But the researchers were able to successfully produce offspring using in vitro fertilization.
|
|
Since they couldn't produce offspring, the sterile screwworms flies should gradually eradicate the species.
|
|
Apparently beluga whales and narwhals produce offspring with big, burly heads — but, sadly, no tusks.
|
|
That gets problematic, though, when you consider that different species can get together and produce offspring.
|
|
And unfortunately for his species, Dr. Sischo says, he could not produce offspring without a mate.
|
|
Great whites, meanwhile, may take as long as 33 years before they begin to produce offspring.
|
|
When they mate with female mosquitoes in the wild, they produce offspring that cannot survive to adulthood.
|
|
The Australian scientists who made it happen say it's the oldest sperm ever used to produce offspring.
|
|
One reason for this is a high rate of sperm abnormality, meaning many males that mate never produce offspring.
|
|
"Every year in spring, the lemurs are among the first species to produce offspring," zoo director Dagmar Schratter said.
|
|
Scientists are also perfecting mosquitoes genetically modified to produce offspring that die young, but that approach requires more testing.
|
|
But the country's frigid climate hadn't been ideal for the beasts, and the girls hadn't been able to produce offspring.
|
|
When these insects are born, they will produce offspring that is unable to transmit a variety of diseases, including Zika.
|
|
Geneticists advised breeding certain species together to produce offspring closer to the qualities of an auroch, and then breed the offspring.
|
|
Hybridization is already rather common in cetaceans, Skovrind told Gizmodo, so they weren't surprised that the two were able to produce offspring.
|
|
Oxitec has made a name for itself in the pest-prevention business by making mosquitoes and other insects that can't produce offspring.
|
|
If she and your son marry and produce offspring, you will be entitled to express grandparental concern about sharp objects in tiny mouths.
|
|
On the flip side, if resources are scarce, the animal will devote these meagre resources to sustaining itself, rather than trying to produce offspring.
|
|
The so-called Medfly is a devastating agricultural pest, and by engineering it to produce offspring that cannot survive, Oxitec hopes to cull its numbers.
|
|
In each generation, the solutions that perform best on some metric—the ability to control a two-legged robot, say—are selected and produce offspring.
|
|
Plus, since the bricks can produce offspring, builders could also grow the material at a construction site, reducing emissions from the manufacturing and transportation processes.
|
|
Laws were passed to keep Chinese women out of the country, so that the Chinese males who were brought over for menial labor couldn't produce offspring.
|
|
They do, however, mate with disease-carrying female Aedes aegypti insects and produce offspring that, like its genetically modified father, die before it can reach adulthood.
|
|
"Asexual reproduction should dominate and sex should be rare because sex is enormously wasteful, primarily because males don't produce offspring, (at least not directly)," Auld says.
|
|
"So getting them back to health and having them potentially reproduce in the wild, and produce offspring, has a many-magnitude effect" on the overall population.
|
|
Theoretically, the Mandarin could mate with a native duck, an ornithologist with the Cornell Lab of Ornithology said, although it's unclear if they could produce offspring.
|
|
To start, sexual populations of G. nakajimai do occasionally produce offspring from unfertilized eggs, which perhaps "pre-adapted" them to get along fine without males, he said.
|
|
But activists say the biggest threat is the genetic impact of farmed fish that escape their pens, reproduce with wild salmon and produce offspring ill-equipped to survive.
|
|
The company, Oxitec, inserts a modified gene into male mosquitoes so that when they mate with females in the wild, they will produce offspring that die before they reach adulthood.
|
|
Artificial insemination -- an assisted reproductive technology -- has been used to produce offspring with 60 mammals, including the giant panda, black-footed ferret and Asian elephant, and 35 non-domestic birds.
|
|
For this experiment, the researchers wanted to take it a step further and see if it was possible for male mice to produce offspring without any y-chromosome genes at all.
|
|
There are about 3993 million deer in the lower 48 states, 47 million ducks, a million elk, and 15 million pheasants, and they produce offspring annually and from a young age.
|
|
Verily's male mosquitoes were infected with the Wolbachia bacteria, which is harmless to humans, but when they mate with and infect their female counterparts, it makes their eggs unable to produce offspring.
|
|
Previous studies in monkeys got part of the way there: researchers showed that the transplanted testicle tissue could produce sperm — but stopped short of proving that the sperm could actually produce offspring.
|
|
Put simply, while you no longer need a dick to be President of the United States, you do need to fuck people of the opposite sex, in a matrimonial setting, and produce offspring.
|
|
When the genetically altered males mate with the local female mosquito population they produce offspring that die while still young, minimizing the spread of diseases carried by the animals, including Zika and dengue.
|
|
This has largely informed our understanding of reproduction ever since, and until now, no one has been able to show that any cell other than an egg cell can combine with sperm to produce offspring.
|
|
Scientist Nathan Morehouse has discovered that one of the most common butterflies — the white cabbage — has an unusual sex life, including large, protein-rich ejaculates that nourish the females as they produce offspring, according to the Atlantic.
|
|
That means that, for the most part, dogs of any breed can mate and produce offspring — but they also have subtle genetic variants that determine which dog is small or big and which dogs have curly or long, black fur.
|
|
Genetically-modified mosquitoes that produce offspring that die before they mature to the adult stage (effectively wiping out the population) are alreadybeing tested on a small scale in Brazil and theFood and Drug Administration is considering a bid to test the modded skeeters in Florida.
|
|
But the Cape honeybee, a subspecies that lives in the Fynbos ecoregion, a unique area of incredible diversity along the southwestern tip of South Africa, evolved a workaround where, in some cases, female workers can become something like a queen and produce offspring of their own.
|
|
Ms Monk and her co-authors question the first assumption by pointing out that many animals seem to mate at a frequency far higher than looks necessary merely to reproduce—meaning that the proportional costs of any instance of sexual activity which does not produce offspring must be low.
|
|
The most notable, perhaps, is that Tilikum "inspired" people by being a part of a documentary that demonstrated how life for a killer whale is worse in captivity than it is in the wild, as the whales were shown to be mistreated, perform odd stunts, and forced to produce offspring.
|
|
"The New Elite marry each other, combining their large incomes and genius genes, and then produce offspring who get the benefit of both," Charles Murray, a scholar at the American Enterprise Institute and the author of "Coming Apart," wrote in the Washington Post: Far from spending their college years in a meritocratic melting pot, the New Elite spend school with people who are mostly just like them — which might not be so bad, except that so many of them have been ensconced in affluent suburbs from birth and have never been outside the bubble of privilege.
|
|
Older females produce offspring with reduced size and at increased interbrood intervals.
|
|
"True" parthenogenesis is a form of asexual reproduction in all-female species that produce offspring without any male involvement.
|
|
Other couplings between male deities could be viewed positively and even produce offspring, as in one text in which Khnum is born from the union of Ra and Shu.
|
|
Females produce offspring starting at age 5, and thereafter in a cycle of 2 years. Typically, Bactrian camels seen alone are postdispersal young individuals which have just reached sexual maturity.
|
|
The female worms produce offspring continually. The vast majority of larvae will never find a suitable place to settle, but sufficient numbers will do so to provide the next generation of worms.
|
|
Johanna of Hanau-Münzenberg married twice: #From September 1637Dek, p. 30: 1 February 1637. with Wild- and Rhinegrave Wolfgang Friedrich of Salm (1589 – 24 December 1638). The marriage did not produce offspring.
|
|
Little is known regarding the mating behavior of black- spotted cuscuses. Courting is typically performed on tree limbs. Black-spotted cuscuses produce offspring via sexual reproduction. They are viviparous, with the mother birthing live young.
|
|
Under good conditions the blind and wingless form predominates, but if their surroundings become too tough, they produce offspring which develop into winged adults with eyes. The wings are paddle shaped, and have reduced venation.
|
|
Internal and external organs are included in the reproductive system. There are two reproductive systems including the male and female, which contain different organs from one another. These systems work together in order to produce offspring.
|
|
Primitive markings on non-duns can be seasonal, visible only when the horse is shedding its coat. Such primitive markings also seem to be heritable, as horses with prominent countershading dorsals often produce offspring with the same.
|
|
E. ijimae is viviparous. Neonates begin reproductive activity in the second or third summer and third spring after birth. Studies have suggested that E. ijimae are income breeders that rely on temporal energy intake to produce offspring.
|
|
North American river otters are polygynous. Females usually do not reproduce until two years of age, although yearlings produce offspring on occasion. Males are sexually mature at two years of age. The number of corpora lutea increases directly with age.
|
|
Formosa was exported to France in 1879 and died there in February 1881. While she did not produce offspring that excelled at racing, her daughters that were exported to Germany and New Zealand did produce descendants that were successful racers.
|
|
Facultative parthenogenesis is the term for when a female can produce offspring either sexually or via asexual reproduction.Bell, G. (1982). The Masterpiece of Nature: The Evolution and Genetics of Sexuality, University of California Press, Berkeley, pp. 1- 635 (see page 295).
|
|
Schuyler wanted to marry an Aryan man to boost her career and produce offspring she deemed ideal. Schuyler and her father were members of the John Birch Society. In addition to her native English language, she spoke French, Italian, Spanish, Portuguese, and German.
|
|
The resultant 'sex-sorted' spermatozoa are then able to be used in conjunction with other assisted reproductive technologies such as artificial insemination or in-vitro fertilization (IVF) to produce offspring of the desired sex - in farming animals but also in human medical practice.
|
|
Germline mosacisim disorders are usually inherited in a pattern that suggests that the condition is dominant in ether or both of the parents. That said, diverging from Mendelian gene inheritance patterns, a parent with a recessive allele can produce offspring expressing the phenotype as dominant through germline mosaicism. A situation may also arise in which the parents have milder phenotypic expression of a mutation yet produce offspring with more expressive phenotypic variance and a more frequent sibling recurrences of the mutation. Diseases caused by germline mosaicism can be difficult to diagnose as genetically-inherited because the mutant alleles are not likely to be present in the somatic cells.
|
|
The bandy-bandy is oviparous i.e. produces offspring within eggs that are hatched after birth. Females seasonally produce offspring, laying eggs in the late summer (February - March) after undergoing vitellogenesis in October. Both live-bearing and oviparous Australian elapid snakes follow a similar seasonal reproductive cycle.
|
|
VSH activity results in (1) an abnormally low proportion of mites that produce offspring within the population that remains in capped brood and (2) reducing the brood infestation rate by greater than 70%. The specifics of how hygienic bees detect mite infested brood currently are unknown.
|
|
Sylon hippolytes are r-strategists. An externa can only produce offspring once during its lifetime. Therefore, the parasite utilizes an enormous amount of energy towards producing as many eggs as possible for reproduction. The size of the parasitic sac has proportional relationship with the size of its host.
|
|
On the other hand, a reciprocal cross (SI x SC) will not produce offspring, because the pollen tubes will not reach the ovules. This is known as unilateral incompatibility, which also occurs when two SC or two SI species are crossed.Hadley , H.H. & Openshaw, S.J. 1980. Interspecific and intergeneric hybridization.
|
|
A black roan Abyssinian. This color is linked with potentially lethal defects. Two roan Abyssinians should not be bred, because they will produce offspring with genetic problems linked to the white gene that produces the coloration. A roan Abyssinian can be safely bred to any other color, however.
|
|
Uniparental inheritance refers to the fact that, in most organisms, many offspring inherit organelle genes from only one parent. However, this is not a general law. Many organisms that have the ability to differentiate maternal and paternal sexes will produce offspring with a mixture of maternal, paternal, and biparental mitochondrial DNA.
|
|
Graph of Total Fertility Rate vs. GDP (PPP) per capita of the corresponding country, 2015. Income and fertility is the association between monetary gain on one hand, and the tendency to produce offspring on the other. There is generally an inverse correlation between income and the total fertility rate within and between nations.
|
|
Hybridization is when two different species or genetically different varieties of the same species are able to breed and produce offspring together. The offspring may have limited reproductive capability. T. intermedia has successfully been able to mate with a similar moth, Tegeticula cassandra. Both have incredibly similar superficial ovipositor and aedeagus physiology.
|
|
Breeding pair is a pair of animals which cooperate over time to produce offspring with some form of a bond between the individuals.Gaston, A. J. "The evolution of group territorial behavior and cooperative breeding." The American Naturalist 112.988 (1978): 1091-1100. For example, many birds mate for a breeding season or sometimes for life.
|
|
However, several chromosomes show structural differences in the location and size of C-heterochromatin blocks. In nature, the two species do not meet, but will mate and produce offspring in captivity. However, both reciprocal crosses produce sterile hybrid males and females with decreased fertility. There is a clear effect in which types the parents are.
|
|
Another cost of living in one-male social groups is that there is a high occurrence of inbreeding. This means that closely related individuals can mate and produce offspring. This results in decreasing genetic diversity with subsequent generations of the species. For example, inbreeding has been studied in one-male groups of sun-tailed monkeys (Cercopithecus solatus).
|
|
Vespiform are an insectoid species resembling giant wasps, born en masse in hives in the Silfrax Galaxy. Each possesses the ability to morph into other species. It also has the ability to breed with other species, including humans, to produce offspring. The Monster Files feature establishes them as an ancient race and that they have fought the Quark rebels.
|
|
At first, field trials were performed on Grand Cayman, starting in 2009. Approximately 3.3 million of the transgenic male Aedes aegypti mosquitoes were released. The experiments demonstrated that the animals were able to survive in this environment and produce offspring. Some eleven weeks after the release, a decline in the A. aegypti mosquito population by about 80% was observed.
|
|
Cleistogamy allows plants to produce offspring year round and have more chances for establishment. This system is especially important in violets, as these plants are often weak competitors for pollination due to their small size. Many violet species exhibit two modes of seed dispersal. Once seed capsules have matured, seeds are dispelled around the plant through explosive dehiscence.
|
|
Those individuals are more likely to survive to produce offspring bearing that allele. The population will continue for more generations because of the success of these individuals. The academic field of population genetics includes several hypotheses and theories regarding genetic diversity. The neutral theory of evolution proposes that diversity is the result of the accumulation of neutral substitutions.
|
|
Therefore, during mating season they produce offspring who also stay in the same general area when they mature. It makes sense not to move from an area if it is providing for your most basic needs. The common name for Eliomys is the garden dormouse. Dryomys are often compared to Eliomys as they have many similarities.
|
|
Oxyurida, in general, tend to take advantage of the amazing colonizing ability of the females. An individual female can colonize a host if she can last long enough to mate and produce offspring with parthogenetically birthed sons. There is evidence that mother- son matings occur in these species. Thick-shelled eggs are the transmission and dispersal stage of G. batrachiensis.
|
|
There is an increased chance for women over the age of 35 to have multiple births. IVF is a common genetic and ethical topic. Through IVF individuals can produce offspring successfully when natural procreation is not viable. However, in vitro can become genetically specific and allow for the selection of particular genes or expressible traits to be dominantly present in the formed embryo.
|
|
Inbreeding depression has also been found to occur more gradually than predicted in some wild populations, such as in the highly inbred population of Scandinavian wolves. This appears to be due to a selection pressure for more heterozygous individuals, which generally are in better condition and so are more likely to become one of the few animals to breed and produce offspring.
|
|
Adult male mandrills with alpha status display vivid colouration on their skin, while those with beta status are more dull in colour. Both types of males engage in mating, but only the dominant alpha males have the ability to produce offspring. Male mandrills sometimes fight for breeding rights which results in dominance. Though conflicts are rare, they can be deadly.
|
|
Selection for and against genes that increase flight traits showed rapid changes in flight traits in both directions. There is, however, a trade-off between mobility and fitness. Research has shown that sedentary females have higher fecundity, or the ability to produce offspring, than mobile females. Sedentary females are larger in size, lay more eggs, and live longer than mobile females.
|
|
Overall, P. occidentalis has a very high relatedness, primarily due to the number of queens in the colony over time. As the colony grows, the number of queens decreases. P. occidentalis follows cyclic oligogyny, which increases genetic relatedness among the colony members because over time, as the queens die, fewer queens produce offspring. The fewer the reproducers, the higher the relatedness.
|
|
A baby Komodo dragon, Varanus komodoensis, produced through parthenogenesis. Komodo dragons are an example of a species which can produce offspring both through sexual reproduction and parthenogenesis. Some species reproduce exclusively by parthenogenesis (such as the bdelloid rotifers), while others can switch between sexual reproduction and parthenogenesis. This is called facultative parthenogenesis (other terms are cyclical parthenogenesis, heterogamy or heterogony).
|
|
However, if a gray horse is heterozygous (Gg), meaning it inherits one copy of the recessive gene (g), that animal may produce offspring who are not gray, depending on the genetics of the other parent and Mendelian inheritance principles. Genetic testing is now possible to determine whether a horse is homozygous or heterozygous for gray."Gray - Horse Coat Color DNA Testing." Animal Genetics, Incorporated.
|
|
Meerkats have foreclaws adapted for digging and have the ability to thermoregulate to survive in their harsh, dry habitat. Three subspecies are recognised. Meerkats are eusocial, and form packs of two to 30 individuals each that occupy home ranges around large. There is a social hierarchy—generally dominant individuals in a pack breed and produce offspring, and the nonbreeding, subordinate members provide altruistic care to the pups.
|
|
Gottfried is an intelligent man that commanded the nation for several hundred years. As a pure-blood, it was difficult for Gottfried to produce offspring. Thus, when Bridget was born, she was allowed to be princess and heir in the off chance that Gottfried died. As soon as Adelheid was born, Gottfried banished his older daughter in order to prevent civil war between the two children.
|
|
Alternative slicing of a gene homologous to the gemini transcription factor of Drosophila controls worker sterility. Knocking out an exon resulted in rapid worker ovary activation. A 9 nucleotide deletion from the normal altruistic worker genome may turn a honeybee into a parasite. As for many eusocial insects, termite workers are totipotent and rarely produce offspring although they are capable of reproduction when the breeding pair dies.
|
|
Females of matching body sizes tend to produce more numerous but smaller-sized offspring in high-predation conditions. Female guppies first produce offspring at 10–20 weeks of age, and they continue to reproduce until 20–34 months of age. Male guppies mature in 7 weeks or less. Total lifespan of guppies in the wild varies greatly, but it is typically around 2 years.
|
|
Most aquatic animals, except for aquatic mammals and reptiles, reproduce through the process of spawning. Spawn consists of the reproductive cells (gametes) of many aquatic animals, some of which will become fertilized and produce offspring. The process of spawning typically involves females releasing ova (unfertilized eggs) into the water, often in large quantities, while males simultaneously or sequentially release spermatozoa (milt) to fertilize the eggs.Spawn Fishbase Glossary.
|
|
However, self-pollination can be advantageous, allowing plants to spread beyond the range of suitable pollinators or produce offspring in areas where pollinator populations have been greatly reduced or are naturally variable. Pollination can also be accomplished by cross-pollination. Cross-pollination is the transfer of pollen, by wind or animals such as insects and birds, from the anther to the stigma of flowers on separate plants.
|
|
The second launch, of Foton-M2, was, however, a success. Foton-M3 was launched on 14 September 2007 carried by a Soyuz-U rocket lifting off from the Baikonur Cosmodrome in Kazakhstan with Nadezhda, a cockroach that was the first earth creature to produce offspring that had been conceived in space. It returned successfully to Earth on September 26, 2007, landing in Kazakhstan at 7:58 GMT.
|
|
This concept is not always useful, particularly when it comes to hybrids. Other species concepts include phylogenetic species concept which describes a species as the smallest identifiable monophyletic group of organisms within which there is a parental pattern of ancestry and descent. This concept defines species on the identifiable. It would also suggest that until two identifiable groups actually produce offspring, they remain separate species.
|
|
The spawn metaphor, i.e., to produce offspring as in egg deposition, had its early use in the VMS, now OpenVMS, operating system (1977). In academia, there existed a lively debate between proponents of the Unix fork (crude copy of memory layout, but fast) versus VMS's spawn (reliable construction of process parameters, but slower). This debate revived when the VMS spawning mechanism was inherited by Windows NT (1993).
|
|
Female workers forage to feed themselves and non-foragers, such as the queen, larvae, and males. They help to build the nest and care for the larvae. Workers may mate with males and remain inseminated even if they are never able to attain queenship and produce offspring. Worker-worker relatedness is not asymmetrically higher than relatedness between workers and males or workers and the queen.
|
|
Although workers are generally unable to mate, they have functional ovaries that allow them to lay eggs. Because these eggs are not fertilised, they would become male wasps. Workers would want to produce such wasps as they would be more closely related to their own sons than to their mothers' sons, or brothers. However, it is not in the queens best interest for workers to produce offspring.
|
|
Darwin added to that body of work with his scientific observations about the ability of science to change species. These accounts contributed to Darwin's theory of natural selection. For thousands of years, humans have used selective breeding to improve the production of crops and livestock to use them for food. In selective breeding, organisms with desirable characteristics are mated to produce offspring with the same characteristics.
|
|
The presence of selfish genetic elements can be difficult to detect in natural populations. Instead, their phenotypic consequences often become apparent in hybrids. The first reason for this is that some selfish genetic elements rapidly sweep to fixation, and the phenotypic effects will therefore not be segregating in the population. Hybridization events, however, will produce offspring with and without the selfish genetic elements and so reveal their presence.
|
|
The second son of Ranuccio II Farnese and Maria d'Este of Modena, the Duke, despite his efforts otherwise, saw Parma declared a fief of the Duchy of Milan, an Austrian province in Italy, towards the end of the war.Armstrong, p 6. His inability to produce offspring, combined with his brother Antonio's barrenness, lead to the accession of his niece the Queen of Spain's eldest son, Don Carlos, in 1731.
|
|
As the snails can reproduce both sexually and asexually, the snail has been used as a model organism for studying the costs and benefits of sexual reproduction. Asexual reproduction allows all members of a population to produce offspring and avoids the costs involved in finding mates. However, asexual offspring are clonal, so lack variation. This makes them susceptible to parasites, as the entire clonal population has the same resistance mechanisms.
|
|
Other honey bee species, including the giant honey bees Apis dorsata and Apis laboriosa, generally construct nests consisting of a single comb in open areas.Winston, Mark L. The biology of the honey bee. Harvard University Press, 1991. However, despite the striking similarities between Apis cerana and Apis mellifera, there is evidence to suggest that these two species are quite distinct; for example, mating between these species does not produce offspring.
|
|
Poopsie turned 37 on 27 December 2010. She was euthanized on 9 November 2011 following arthritic conditions, compromised mobility, and depression. The Salisbury Zoo was also home to the oldest known Andean bear, Gritto, to successfully produce offspring, when he sired a cub, Alba, born on 23 January 2015. Gritto, who was born on 28 January 1991, was euthanized on 15 October 2015 due to stroke-like symptoms.
|
|
Within the wolf pack, the alphas, now more commonly referred to as the breeding pair, are the only wolves in the group which breed and produce offspring; they are the matriarch and patriarch of the family. It was previously believed to be common for an aging or sick alpha to be replaced by one of their offspring, but more recent studies have shown this incestuous behavior to be very rare.
|
|
Mate value has been seen to differ between males and females. Various studies have been conducted to determine what these are, and the extent to which they exist. Researchers have found that men place a much bigger emphasis on the reproductive capacity of a mate in order to ensure they are able to produce offspring. This reproductive capacity may be determined by focusing on the youth and attractiveness of a female.
|
|
This is due to the fact that when women are at their peak fertility, this is the most optimal time for them to mate and produce offspring. However, this tends to be only applied in situations when women are faced with rivals who they consider to be attractive. When with an unattractive rival, women might not necessarily see them posing any threat, as they would feel more attractive in comparison.
|
|
Many species within this group produce offspring that are self-sufficient, and are able to regulate their body temperatures and forage for themselves immediately after birth, thereby eliminating the need for parental care. Maternal care exists in crocodilians, where the mother assists hatchlings by transporting them in her mouth from the nest to the water. She may stay with the young for up to several months.Pooley, A. (1977).
|
|
All of these traits are heritable, and will determine if the foal will be a success in its chosen discipline. The offspring, or "get", of a stallion are often excellent indicators of his ability to pass on his characteristics, and the particular traits he actually passes on. Some stallions are fantastic performers but never produce offspring of comparable quality. Others sire fillies of great abilities but not colts.
|
|
A woman also had a proposition for him, and he was shocked that humans even charged money for what she was proposing. When a man's car was stolen, Blackwulf tried to help by hurling his Shadowlance at it, but he destroyed the car in the process, upsetting the owner. At that moment, the Celestial’s Godstalker appeared, thinking that Blackwulf was his father Tantalus. Godstalker did not believe that Tantalus could ever produce offspring.
|
|
Cows typically weigh 1250 to 1500 pounds while bulls can reach a weight of 2300 to 2800 pounds. Hays Converters are an early maturing breed, this feature allows them to breed and produce offspring sooner than other breeds of cattle. Hays chose three particular breeds of cattle in order to achieve the optimal breed of cattle. He achieved this by combination crosses of Holstein cattle on Hereford cattle and Brown Swiss cattle.
|
|
During the winter, blueberry aphids overwinter as tiny eggs at the bases of buds. In the Spring, when young foliage begins to develop, which is usually during bloom, eggs begin to hatch and young aphids move in search for a place to feed. The ideal temperature for the eggs to hatch is around 38 °F [3.3 °C]. Once the aphids are mature, they are able to reproduce sexually and asexually (females produce offspring without mating).
|
|
Recruitment overfishing occurs when the mature adult population (spawning biomass) is depleted to a level where it no longer has the reproductive capacity to replenish itselfthere are not enough adults to produce offspring. Increasing the spawning stock biomass to a target level is the approach taken by managers to restore an overfished population to sustainable levels. This is generally accomplished by placing moratoriums, quotas, and minimum size limits on a fish population.
|
|
In the neo-Darwinian paradigm, one of the assumed definition of a species is that of Mayr’s, which defines species based upon sexual compatibility. Mayr’s definition therefore suggests that individuals that can produce fertile offspring must belong to the same species. However, in hybridization, two organisms produce offspring while being distinct species. During hybridization the characteristics of these two different species are combined yielding a new organism, called a hybrid, thus driving evolution.
|
|
The status quo between Gustav III and his consort was nurtured by the Queen Dowager, who did not want competition in her influence over her son. There were rumors that the King was a homosexual or sexually underdeveloped. His sexuality, which had much effect on Sophia Magdalena's life, as a royal marriage was designed to produce offspring, has been much debated. His sexual inexperience has been blamed on immaturity or his also being asexual.
|
|
Many animals have complex mating rituals require higher levels of cognition to evaluate. Birds are well known for their intense mating displays including swan dances that can last hours or even days. Higher levels of cognition may have evolved to facilitate the formation of longer lasting relationships. Animals that form pair bonds and share parental responsibilities produce offspring that are more likely to survive and reproduce, which increases the fitness of these individuals.
|
|
Colonies of Platythyrea punctata from Florida and the Caribbean Islands produce offspring almost exclusively by automictic thelytoky. Automixis appears to involve central fusion of two of the haploid products of meiosis (see diagram). This form of automixis tends to maintain heterozygosity in transmission of the genome from mother to offspring, and to minimize inbreeding depression. Furthermore, crossover recombination occurs at a greatly reduced rate during meiosis, which likely restrains the transition from heterozygosity to homozygosity.
|
|
Peter II then pursued the murderers of his other brother, Gilles. By 1455, Peter II and his wife, Frances d'Amboise, had failed to produce offspring. Given the health problems of Peter II, this raised the question of succession. To prevent the throne of Brittany from falling into foreign hands, the Duke decided to marry his niece, Margaret, the eldest daughter of his deceased brother Francis, to his cousin, Francis, Count of Étampes.
|
|
In non-human populations it is often possible to collect information in a controlled way. For example, among farm animals it is easy to arrange for a bull to produce offspring from a large number of cows and to control environments. Such experimental control is generally not possible when gathering human data, relying on naturally occurring relationships and environments. In classical quantitative genetics, there were two schools of thought regarding estimation of heritability.
|
|
Cockroaches have been used for space tests. A cockroach given the name Nadezhda was sent into space by Russian scientists as part of a Foton-M mission, during which she mated, and later became the first terrestrial animal to produce offspring that had been conceived in space. Because of their long association with humans, cockroaches are frequently referred to in popular culture. In Western culture, cockroaches are often depicted as dirty pests.
|
|
Female hinnies and mules are not customarily spayed, and may or may not go through estrus. Female mules have been known, on rare occasions, to produce offspring when mated to a horse or donkey, although this is extremely uncommon. Since 1527, sixty cases of foals born to female mules around the world have been documented. In contrast, according to the ADMS, there is only one known case of a female hinny doing so.
|
|
Ramshorn snails are hermaphroditic;Ramshorn Snail – The Care, Feeding and Breeding of Ramshorn Snails Red Ramshorn Snail Factoids two organisms of any sex have the ability to breed and produce offspring. Ramshorn snails lay eggs in globules, which tend to be brownish in color. The globules contain about a dozen or so eggs, though it can vary. The globules are translucent, so it is possible to visually see the new snails develop in size.
|
|
In 1983, she was moved to Rangatira Island so that the other breeding female, Old Green who wasn't directly related to her would have a chance to produce offspring and the remaining genetic diversity could be preserved. Sadly none of Old Green's offspring managed to survive to the stage where they could breed. That resulted in Old Green's genes being lost. Through Old Blue's breeding period, she managed to raise eleven chicks.
|
|
Finally, fluctuating or declining territory value should reduce the extent of site fidelity. The extent to which female territorial preferences remain constant throughout the mating season will be very important in territory value. Males are expected to abandon territories at times when they no longer have the potential to produce offspring. It is also conceivable that in X. sonorina, the quality of the male's sex pheromone may be a key feature determining his sexual attractiveness.
|
|
The oldest semen believed to be in existence was from a sire named Cottonade Emmet, who was a member of the American Breeders Service sire battery in 1952. Semen was collected on Emmet in November 1952 and has been used several times to produce offspring. However, the last time any such offspring was born was in the mid-1980s. Osborndale Ivanhoe, who was probably the most famous Holstein bull of the early semen era, died in November 1963.
|
|
A fight ensues, during which Annette is thrown over a railing. Ada learns that the golden locket contains a sample of the G-virus, and later – taken over by her emotions – returns to Leon, tending to his bullet wound. Meanwhile, Claire is reunited with Sherry and discovers that William has implanted his daughter with an embryo to produce offspring. Leon, Ada, Claire, and Sherry advance through an abandoned factory connected to Umbrella's secret underground research facility.
|
|
Empress Bruttia Crispina, draped bust On the basis of a misreading of HA Commodus 5.9 and Dio 73.4.6, her fall is sometimes wrongly associated with Lucilla's conspiracy to assassinate Commodus in 181 or 182. Her name continues to appear in inscriptions until as late as 191 (). Her eventual exile and death may instead have been a result of the fall of Marcus Aurelius Cleander, or of Commodus's inability to produce offspring with her to ensure the dynastic succession.
|
|
The trends in breeding these dogs are to produce offspring less aggressive towards people.Sider Sedefchev: The Karakachan Dog – Continuation of an old Bulgarian Tradition in: CDPNews No 9, December 2005 Karakachan dogs are large, long-haired, massive dogs with a well-developed musculature and well-expressed sexual dimorphism. Males are a minimum of 63 cm in height; females at least 60 cm. Karakachan dogs are used as herding dogs to escort and guard sheep and goat herds in Bulgaria.
|
|
Drug resistance in bacteria is an example of an outcome of natural selection. When a drug is used on a species of bacteria, those that cannot resist die and do not produce offspring, while those that survive potentially pass on the resistance gene to the next generation (vertical gene transmission). The resistance gene can also be passed on to one bacterium by another of a different species (horizontal gene transmission). Because of this, the drug resistance increases over generations.
|
|
Janet Evason lives on Whileaway, an all-female human colony planet whose inhabitants produce offspring by chemically combining ova because all their males died in a plague 30 generations earlier. When male astronauts arrive from Earth, they assume that Whileaway society must be in some way deficient, and announce that they will reproduce with the women. Janet's wife tries to kill the astronauts; Janet stops her, but realizes that their very existence will change Whileaway society forever.
|
|
According to Claude Levi- Strauss, the custom of couvade reinforces the institution of the family in some societies by "welding" together men and their wives and future children. Conflict, Order and Action (Chapter 33), Edward Ksenych & David Liu, 2001 Couvade has been interpreted by some as a manifestation of male womb envy, with the ritual serving as a psychological defense mechanism in which men appropriate or attempt to compensate for women's innate ability to produce offspring.
|
|
The majority of offspring produced in the first brood are female, ranging from 74-81% of the offspring. Only about 50% of foundresses survive to the production of the second brood. This means that some unmated workers will produce offspring, which leads to more male offspring being produced in the second brood than in the first. Therefore, the ratio of males produced in the second brood most likely depends upon whether the foundress does or does not survive.
|
|
This species is oviparous, meaning these turtles produce offspring by laying eggs only and do not provide parental care outside of nest-building. Thus, the location and quality of nesting sites determine the offspring survival and fitness, so females invest significant time and energy into nest site selection and construction. Females select nest sites based on soil temperature (preferring warmer temperature nest sites), but not soil composition. Average nest size is four inches wide and three inches deep.
|
|
The programme showed examples of individuals with serious inherited diseases being crowned show champions. Such individuals are not forbidden from being bred and some go on to produce offspring who inherit the same diseases. It was reported that the 2003 Crufts champion – a Pekingese – had to sit on an ice pack to have its photo taken. The programme explained that the breed tends to overheat due to its inability to breathe properly, as a result of its flattened face.
|
|
The Western Australian aviculturalist, Alwyn Pepper, began a breeding program in 1962, using eggs obtained from a fallen nest in its native habitat. The clutch was incubated by Bengalese finches (Lonchura domestica) and a breeding pair were reared to successfully produce offspring within the first year. Pepper's work on this breeding program was acknowledged with an award from the Avicultural Society of Australia in 1986. Research into captive breeding was continued in Western Australia by Hutton.
|
|
Co- dominance, where allelic products co-exist in the phenotype, is different from incomplete dominance, where the quantitative interaction of allele products produces an intermediate phenotype. For example, in co-dominance, a red homozygous flower and a white homozygous flower will produce offspring that have red and white spots. When plants of the F1 generation are self- pollinated, the phenotypic and genotypic ratio of the F2 generation will be 1:2:1 (Red:Spotted:White). These ratios are the same as those for incomplete dominance.
|
|
Fertility is the natural capability to produce offspring. As a measure, fertility rate is the number of offspring born per mating pair, individual or population. Fertility differs from fecundity, which is defined as the potential for reproduction (influenced by gamete production, fertilization and carrying a pregnancy to term) A lack of fertility is infertility while a lack of fecundity would be called sterility. Human fertility depends on factors of nutrition, sexual behavior, consanguinity, culture, instinct, endocrinology, timing, economics, way of life, and emotions.
|
|
In the Middle Ages the upper socioeconomic groups generally included royalty and nobility. Conduct books from the period present an image of the role of elite women being to obey their spouse, guard their virtue, produce offspring, and to oversee the operation of the household. For those women who did adhere to these traditional roles, the responsibilities could be considerable, with households sometimes including dozens of people. Further, when their husbands were away the role of women could increase substantially.
|
|
A parthenogenetic species can undergo a more rapid population increase than a sexual species because all parthenotes are female and produce offspring, while in sexual species half of all individuals are males and do not give birth to offspring. Additionally, laboratory experiments have revealed that even obligate parthenotes retain the capability of incorporating new genetic material through sexual reproduction to form new parthenogenetic lineages, and the ability to outcross on occasion may explain the lengthy evolutionary persistence of some parthenogenetic species.
|
|
In hybridogenesis, females of a unisexual species mate with a male of a related species and utilize their genetic material in order to produce offspring. However, in spite of this requirement, the genetic material of the male is not passed on to the next generation. Just prior to meiosis, during mitotic division, spindle fibers attach to the maternal chromosomes, leaving the paternal chromosomes in the cytoplasm. The paternal chromosomes are therefore excluded from nascent eggs, without recombination having typically occurred.
|
|
Sterilizing disables the sex organs of the individual, making it impossible to reproduce. Procreation became a privilege because only authorized individuals were allowed to produce offspring—their characteristics were considered specifically desirable. Although sterilization in the United States was more limited than it was in Germany, German racial hygienists highlighted that sterilization practices in some areas of the United States were more extreme than those in Nazi Germany. The International Federation of Eugenic Organization held a conference in the Netherlands in 1936.
|
|
Ovarian tissue cryopreservation also poses a risk of reintroducing malignant cells after cancer recovery, particular in those with previous leukaemia. Artificial ovaries could be an effective alternative in fertility preservation. The artificial ovary aims to replicate it’s natural counterpart by producing oocytes and releasing steroid hormones. To date, no human oocytes have been fertilised or used to produce offspring using an artificial ovary and it is unlikely that this will occur until further research has been completed and bioethical concerns have been considered.
|
|
The scientists fear she may mate with human males and produce offspring that could eliminate the human race. Sil is intent on producing offspring as soon as possible, and kills several people to prevent them from notifying the authorities or simply to use their clothing. Sil first tries to mate with Robbie (Anthony Guidera), but after sensing that he is diabetic, she rejects him. Unsatisfied, he tries to rape her, prompting her to kill him by puncturing his skull with her tongue.
|
|
Not in > order to produce offspring, but to satisfy lust, are they eager for > corruption. John T. Noonan Jr. said that the Gnostics described by Epiphanius practiced "nonprocreative sexual acts" as a centre in their religious rituals. Epiphanius calls these practices, which include coitus interruptus, masturbation, and homosexual acts, as "the rites and ceremonies of the devil". Shenoute (348-466), another Byzantine who is considered a saint in Oriental Orthodoxy, views masturbation as a sexual "misconduct" and an "outright illicit sexual activity".
|
|
And just as female mules and hinnies only very rarely produce offspring the same appears to be true of zebroids. Considering zebroids are much less common as mules the chances of a fertile zebroid mare are very slim. Only ONE case of such a mare was reported : The zebroid mare of a zebra mare x draft horse stallion produced a foal when she was bred back to her sire but the foal died of lightning and she did not survive it much longer.
|
|
Altruism in animals describes a range of behaviors performed by animals that may be to their own disadvantage but which benefit others. The costs and benefits are measured in terms of reproductive fitness, or expected number of offspring. So by behaving altruistically, an organism reduces the number of offspring it is likely to produce itself, but boosts the likelihood that other organisms are to produce offspring. There are other forms of altruism in nature other than risk-taking behavior, such as reciprocal altruism.
|
|
Cryptic female choice falls under the conflict in reproductive patterns. Cryptic female choice results from process that occurs after intromission which allows the female to preferentially fertilize or produce offspring with a particular male phenotype. It is thought that if the female's cryptic choice provides her with indirect genetic benefits in the form of more fit offspring, any male phenotype that limits female cryptic choice will induce a cost on the female. Often, cryptic female choice occurs in polyandrous or polygamous species.
|
|
This male hybrid was intermediate between the puma and leopard in color and pattern, having faint leopard spots on a puma-colored background. The body length was much less than either parent, while the tail was long, like the puma. Hagenbeck apparently bred these hybrids at the suggestion of an unidentified menagerie owner; however, the hybrids were considered dull and uninteresting. Modern geneticists find them more interesting because the leopard and the puma were not considered to be closely enough related to produce offspring.
|
|
Golden Shepherd has more average mongrel traits than either parent Guessing a mixed-breed's ancestry can be difficult even for knowledgeable dog observers, because mixed-breeds have much more genetic variation than purebreds. For example, two black mixed- breed dogs might each have recessive genes that produce a blond coat and, therefore, produce offspring looking unlike their parents. Starting in 2007, genetic analysis has become available to the public. The companies claim their DNA-based diagnostic test can genetically determine the breed composition of mixed-breed dogs.
|
|
A stricter definition insists that breeds are "consistent and predictable genetic entities", which means that individuals from that breed will produce offspring that is predictably similar to their genitors, and that this similarity is genetically based. This biological definition is useful for conservation, which treats breeds as reliable sources of genetic diversity. Conservation organisations each have their own definition of what constitutes a rare breed. The Rare Breeds Survival Trust (RBST) and The Livestock Conservancy (TLC) both divide rare breeds into five categories, "critical" being the rarest.
|
|
As a result, a female can mate with multiple males and choose when to fertilize her eggs. Furthermore, females can also produce offspring that can feature genetic material from multiple males in a single clutch if she mated with more than one male. A product of this system is that males are not guaranteed to successfully reproduce and bear offspring from a single mating. Therefore, it is in their interest to mate with as many females as possible to increase their chance of passing on genetic material.
|
|
There was also a ten-day expedition in 2004. The goal of this was to capture all three birds and bring them to a bird conservation center on the island, in the hope they would produce offspring. On September 9, 2004, one of the remaining birds, a male, was captured and taken to the Maui Bird Conservation Center in Olinda, in an attempt to breed the bird in captivity. However, biologists could not find a mate for the male before it died on November 26, 2004.
|
|
Like other forms of neutering, vasectomy and tubal ligation eliminate the ability to produce offspring. They differ from neutering in that they leave the animal's levels and patterns of sex hormone unchanged. Both sexes will retain their normal reproductive behavior, and other than birth control, none of the advantages and disadvantages listed above apply. This method is favored by some people who seek minimal infringement on the natural state of companion animals to achieve the desired reduction of unwanted births of cats and dogs.
|
|
These organisms can include natural predators or parasites of the pests. Biological pesticides based on entomopathogenic fungi, bacteria and viruses cause disease in the pest species can also be used. Interfering with insects' reproduction can be accomplished by sterilizing males of the target species and releasing them, so that they mate with females but do not produce offspring. This technique was first used on the screwworm fly in 1958 and has since been used with the medfly, the tsetse fly, and the gypsy moth.
|
|
This species shares the southern extent of its range with the banded stingaree (U. cruciatus). The two species apparently hybridize, highly unusual for cartilaginous fish, and produce offspring that are intermediate in color pattern. In a 2007 study of 388 fishes, these two species were the only two that could not be distinguished on the basis of their cytochrome c gene sequences, attesting to a close evolutionary relationship. Almost the entire range of the yellowback stingaree is under pressure from Australian Commonwealth and State-managed commercial fisheries.
|
|
Wolves use eye contact and posture as an indicator of dominance or submission, which are largely age-based; these postures are rare except in relation to food, as described previously. The smaller and more nuclear a pack is, the status of alpha is less likely to be obtained through fighting, and young wolves instead leave the pack to find a mate and produce offspring of their own.Mech, L. David. 1999. Larger or less-nuclear packs may operate differently and possess more complex and flexible social structures.
|
|
By using cows that produce offspring within a one to two-week period, synchronized breeding allows dairy farmers to artificially inseminate cows for maximum pregnancy rates with minimal effort. BST is a placental lactogen (PL) hormone and falls under the class of growth hormone, or somatotropin. It is relevant to the practice of artificially expediting placental development in farm mammals, specifically dairy cattle. The mechanism through which the hormones of this somatotropin exert their effects can be observed at the cellular and molecular level in placental tissue.
|
|
Birds are social, communicating with visual signals, calls, and songs, and participating in such behaviours as cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of bird species are socially (but not necessarily sexually) monogamous, usually for one breeding season at a time, sometimes for years, but rarely for life. Other species have breeding systems that are polygynous (one male with many females) or, rarely, polyandrous (one female with many males). Birds produce offspring by laying eggs which are fertilised through sexual reproduction.
|
|
A CDC infographic on how antibiotic resistance (a major type of antimicrobial resistance) happens and spreads. Antimicrobial resistance can develop naturally as the evolutionary response of continued exposure to antimicrobials. Natural selection means that organisms that are able to adapt to their environment survive and continue to produce offspring. As a result, the types of microorganisms that are able to survive over time with continued attack by certain antimicrobial agents will naturally become more prevalent in the environment, and those without this resistance will become obsolete.
|
|
Natural selection can act on specific alleles both directly or indirectly. In direct selection, the frequency of the selected allele is favored to the extreme. In cases where an allele is indirectly selected, its frequency increases due to a different linked allele experiencing selection (linkage disequilibrium). The condition of the hybrids under selection can play a role in post-zygotic isolation, as hybrid inviability (a hybrid unable to mature into a fit adult) and sterility (the inability to produce offspring entirely) prohibit gene flow between populations.
|
|
Known parasites of the estuary stingray include the tapeworm Shirleyrhynchus aetobatidis, the nematode Echinocephalus overstreeti and the monogeneans Heterocotyle chin, Empruthotrema dasyatidis and Neoentobdella cribbi. Like other stingrays, the estuary stingray exhibits aplacental viviparity, with the developing embryos sustained initially by yolk and later by histotroph ("uterine milk") produced by the mother. Females probably produce offspring every year. Courtship, in which the male follows the female and bites her disc, has been observed at night in water approximately deep in Hays Inlet from July to October.
|
|
Lower variance in reproductive success and higher costs of physical aggression may explain the lower rates of physical aggression among human females compared to males. Females are in general more likely to produce offspring in their lifetimes than males. Therefore, they have less to gain from fighting and the risk of injury or death would produce greater fitness cost for females. The survival of young children depended more on maternal than paternal care, which underscores the importance of maternal safety, survival, and risk aversion.
|
|
Sudhausia is a genus of nematodes (roundworms) of the family Diplogastridae. They live in association with dung beetles and are primarily known from Africa. Species of Sudhausia show a suite of biological features that, together, are unusual for nematodes and animals in general: hermaphrodites, which are females in form, mature to produce offspring (eggs and larvae) before they are adults and thus even capable of mating, and their eggs grow in size during development. Hermaphrodites are also always live-bearing, which is unusual for nematodes under non-stressful conditions.
|
|
According to the same study, male great white sharks take 26 years to reach sexual maturity, while the females take 33 years to be ready to produce offspring. Great white sharks can swim at speeds of 25 km/hr (16 mph) for short bursts and to depths of . The great white shark has no known natural predators other than, on very rare occasions, the killer whale. It is arguably the world's largest-known extant macropredatory fish, and is one of the primary predators of marine mammals, up to the size of large baleen whales.
|
|
The games are set in the distant future; a time when the planet Earth is mostly ocean, leaving some islands left for civilization to prosper on. Based on in-game dialogue, the series takes place at least in the year 80XX. By this time frame, the original humans have been replaced by artificial lifeforms almost identical to them which can produce offspring with almost no effort. The player controls Mega Man Volnutt, a teenage digger and archaeologist of sorts who searches underground ruins mainly for Quantum Refractors, which are the civilization's primary source of energy.
|
|
Hinnies and mules are hybrids resulting from a cross between a horse and a donkey or between a mare and a donkey, respectively. These animals are nearly always sterile due to the difference in the number of chromosomes between the two parent species. Both horses and donkeys belong to the genus Equus, but Equus caballus has 64 chromosomes, while Equus asinus only has 62. A cross will produce offspring (mule or hinny) with 63 chromosomes, that will not form pairs, which means that they do not divide in a balanced manner during meiosis.
|
|
Same-sex marriage supporters disagreed with the procreation argument and proposed Initiative 957 to challenge the court's assertion. It would have required that all marriages recognized by the state to produce offspring within three years of their solemnization. The initiative was created by the Washington Defense of Marriage Alliance, an LGBT rights group. The Washington Defense of Marriage Alliance hoped to use this to create a test case in order to have a court strike down the measure and highlight what they perceived as the weakness of the Andersen decision's logic.
|
|
Rimu mast occurs only every three to five years, so in rimu- dominant forests, such as those on Whenua Hou, kakapo breeding occurs as infrequently. Another aspect of the kakapo's breeding system is that a female can alter the sex ratio of her offspring depending on her condition. A female in good condition produces more male offspring (males have 30%–40% more body weight than females). Females produce offspring biased towards the dispersive sex when competition for resources (such as food) is high and towards the non- dispersive sex when food is plentiful.
|
|
The peasant class has few rights, and women are expected to marry and produce offspring. Because even peasants are expected to possess the magic of simple illusion, those who do not become outcasts, or "rabble," and are forced to live under the land's surface. Every few generations, the source of power on each planet shifts between animus, the male force, and anima, the female force. When the animus is in power, firstborn men possess the greater magic and a woman loses her magic as she gives birth to more children.
|
|
An IVF technique known as mitochondrial donation or mitochondrial replacement therapy (MRT) results in offspring containing mtDNA from a donor female, and nuclear DNA from the mother and father. In the spindle transfer procedure, the nucleus of an egg is inserted into the cytoplasm of an egg from a donor female which has had its nucleus removed, but still contains the donor female's mtDNA. The composite egg is then fertilized with the male's sperm. The procedure is used when a woman with genetically defective mitochondria wishes to procreate and produce offspring with healthy mitochondria.
|
|
None of the dragons, winged or wyvern, are able to breathe fire, although there is mention that the ancestors of the dragons were able to. The wild, winged dragons and wingless Wyverns are genetically similar enough to successfully produce offspring, and speak the same draconic language, though wild dragons generally despise the Wyverns for their dependence on humans. There are four main types of Wyvern: Leatherback, Hard Green, Gristle, and Brasshide. The Leatherbacks are medium sized dragons, usually weighing around two tons and standing 10–12 feet tall.
|
|
Crocus sativus is unknown in the wild, and its ancestor is unknown. The species Crocus cartwrightianus is the most probable ancestor, but C. thomassi and C. pallasii are still being considered as potential predecessors. Manual vegetative multiplication is necessary to produce offspring for this species as the plant itself is a triploid that is self- incompatible and male sterile, therefore rendering it incapable of sexual reproduction. This inability to reproduce on its own supports the hypothesis that C. sativus is a mutant descending from C. carthwrightianus as a result of selective breeding.
|
|
In Norse mythology, Loki accused Freyr and Freyja of committing incest, in Lokasenna, as they were the son and daughter of Njörðr, the sea deity. It seemed that their father, Njörðr, and their mother were also brother and sister. This is also indicated in the Ynglinga saga, which says that brother-sister marriages were traditional among the Vanir before their alliance with the Aesir, and it was customary for them to produce offspring. In Norse legends, the hero Sigmund and his sister Signy murdered her children and begot a son, Sinfjötli.
|
|
This may lead to DNA methylation or histone modifications which control genic transcription levels. Ecologically, this is an example of the mother utilizing her environment and determining the best method to maximize offspring survival, without actually making a conscious effort to do so. Ecology is generally driven by the ability of an organism to compete to obtain nutrients and successfully reproduce. If a mother is able to gather a plentiful amount of resources, she will have a higher fecundity and produce offspring who are able to grow quickly to avoid predation.
|
|
The life cycle of Chirocephalus diaphanus is extremely fast. The typical duration of a full life cycle is not known, but a figure of around 3 months has been suggested. The eggs are tolerant to drying out; when their habitat fills with water again, some of the eggs will hatch, while others remain dormant. This enables the species to continue to survive in an unpredictable habitat, since some eggs remain in case the habitat does not persist for long enough for the animals to mate and produce offspring.
|
|
Fisher's principle is an evolutionary model that explains why the sex ratio of most species that produce offspring through sexual reproduction is approximately 1:1 between males and females. A. W. F. Edwards has remarked that it is "probably the most celebrated argument in evolutionary biology". Fisher's principle was outlined by Ronald Fisher in his 1930 book The Genetical Theory of Natural Selection (but has been incorrectly attributed as original to Fisher). Fisher couched his argument in terms of parental expenditure, and predicted that parental expenditure on both sexes should be equal.
|
|
436–448 A conflict between the sexes of a species is seen in some species of ants with these reproducers apparently competing to produce offspring that are as closely related to them as possible. The most extreme form involves the production of clonal offspring. An extreme of sexual conflict is seen in Wasmannia auropunctata, where the queens produce diploid daughters by thelytokous parthenogenesis and males produce clones by a process whereby a diploid egg loses its maternal contribution to produce haploid males who are clones of the father.
|
|
Wildlife Sanctuaries , Ventana Wildlife Society After some success, a few birds were released in 1991 and 1992 in Big Sur, and again in 1996 in Arizona near the Grand Canyon. In 1997, the Ventana Wildlife Society began releasing captive-bred California Condors in Big Sur. The birds take six years to mature before they can produce offspring, and a nest was discovered in a redwood tree in 2006. This was the first time in more than 100 years in which a pair of California condors had been seen nesting in Northern California.
|
|
Certain male Argiope bruennichi have an adaptation that they have developed to ensure that they will be the only mate with whom the female can produce offspring. Certain males are able to "plug" the female after they have mated with her to prevent other males from copulating with the female. This plugging involves using the entire male's body, thus allowing him to only mate once. This is a major reason as to why these males are always in a rush to mate after the female has completed her final moult.
|
|
Oecophylla smaragdina queen A queen ant (formerly known as a gyne) is an adult, reproducing female ant in an ant colony; generally she will be the mother of all the other ants in that colony. Some female ants, such as the Cataglyphis, do not need to mate to produce offspring, reproducing through asexual parthenogenesis or cloning, and all of those offspring will be female. Others, like those in the genus Crematogaster, mate in a nuptial flight. Queen offspring ant develop from larvae specially fed in order to become sexually mature among most species.
|
|
Prodryas persephone, a Late Eocene butterfly For example, a butterfly may produce offspring with new mutations. The majority of these mutations will have no effect; but one might change the color of one of the butterfly's offspring, making it harder (or easier) for predators to see. If this color change is advantageous, the chances of this butterfly's surviving and producing its own offspring are a little better, and over time the number of butterflies with this mutation may form a larger percentage of the population. Neutral mutations are defined as mutations whose effects do not influence the fitness of an individual.
|
|
Depending on how far two species have diverged since their most recent common ancestor, it may still be possible for them to produce offspring, as with horses and donkeys mating to produce mules. Such hybrids are generally infertile, due to the two different sets of chromosomes being unable to pair up during meiosis. In this case, closely related species may regularly interbreed, but hybrids will be selected against and the species will remain distinct. However, viable hybrids are occasionally formed and these new species can either have properties intermediate between their parent species, or possess a totally new phenotype.
|
|
The meerkat is a eusocial mammal, forming packs of two to 30 individuals each comprising nearly equal numbers of either sex and multiple family units of pairs and their offspring. Members of a pack take turns at jobs such as looking after pups and keeping a lookout for predators. Meerkats are a cooperatively breeding species—typically the dominant 'breeders' in a pack produce offspring, and the nonbreeding, subordinate 'helpers' provide altruistic care for the pups. This division of labour is not as strictly defined as it is in specialised eusocial species, such as the breeder-worker distinction in ants.
|
|
Researchers estimated that milk-drinking humans could produce offspring up to 19% more fertile than those without the ability, putting the mutation among those under the strongest selection known. As an example of gene-culture co-evolution, communities with lactase persistence and dairy farming took over Europe in several hundred generations, or thousands of years. But this raises a chicken-and-egg type of question: which came first, dairy farming or lactase persistence? To answer this question, population geneticists examined DNA samples extracted from skeletons found in archeological sites in Germany, Hungary, Poland, and Lithuania dating from between 3,800 and 6,000 years ago.
|
|
In at least one hermaphroditic species, self-fertilization occurs when the eggs and sperm are released together. Internal self-fertilization may occur in some other species. One fish species does not reproduce by sexual reproduction but uses sex to produce offspring; Poecilia formosa is a unisex species that uses a form of parthenogenesis called gynogenesis, where unfertilized eggs develop into embryos that produce female offspring. Poecilia formosa mate with males of other fish species that use internal fertilization, the sperm does not fertilize the eggs but stimulates the growth of the eggs which develops into embryos.
|
|
In sexually reproducing populations, both carriers of mutations A and B have a higher fitness and therefore a bigger chance to survive and to produce offspring. When a carrier of mutation A produces offspring with a carrier of mutation B, the more-fit genotype AB can arise. Individuals with genotype AB once again have a higher fitness and therefore they are likely to produce more offspring, assuming that there is no negative interaction between the two mutations. In this way, the relative frequency of both mutation A and B can increase rapidly and both can be fixated simultaneously in the population.
|
|
Furthermore, the laws of the Christian Church, in particular, were important in the evolution of social monogamy in humans. They allowed, even encouraged, poor men to marry and produce offspring, which reduced the gap in reproductive success between the rich and poor, thus resulting in the quick spread of monogamous marriage systems in the western world. According to B. S. Low, culture would appear to have a much larger impact on monogamy in humans than the biological forces that are important for non-human animals. Other theorists use cultural factors influencing reproductive success to explain monogamy.
|
|
Research is currently investigating the possibility of same-sex procreation, which would produce offspring with equal genetic contributions from either two females or two males. This form of reproduction has become a possibility through the creation of either female sperm (containing the genetic material of a female) or male eggs (containing the genetic material of a male). Same-sex procreation would remove the need for lesbian and gay couples to rely on a third party donation of a sperm or an egg for reproduction. The first significant development occurred in 1991, in a patent application filed by U.Penn.
|
|
The reproductive habits of Varanus rosenbergi are closely associated with termite constructions, the above ground nest-mounds of some species, and is thought to rely on these to produce offspring. The use of termitaria provides the newly hatched progeny the favourable conditions within the nest, warmth and regulated humidity, when conditions outside retard the activity of adults. Several other monitor species adopt termitaria as nest sites, those utilized by V. rosenbergi offer regular internal temperatures for most of the year, usually around 30° Celsius, and do not fall below 20 °C at the coolest times of the year.
|
|
Spending equal amounts of resources to produce offspring of either sex is an evolutionarily stable strategy: if the general population deviates from this equilibrium by favoring one sex, one can obtain higher reproductive success with less effort by producing more of the other. For species where the cost of successfully raising one offspring is roughly the same regardless of its sex, this translates to an approximately equal sex ratio. Bacteria of the genus Wolbachia cause skewed sex ratios in some arthropod species as they kill males. Sex-ratio of adult populations of pelagic copepods is usually skewed towards dominance of females.
|
|
In the spotted hyenas, the only way for the males to mate with the females is if they have the female's full cooperation because of the female's peniform clitoris. An increase in the male's status gave them more access to dominant females in the clan. Female dominant hyenas do not mate with multiple males, possibly due to the cost of cleaning their genitalia, which hyenas are seen doing after copulation. Because they will get access to the most dominant and better fit males, they do not need to copulate with multiple males to produce offspring of higher fitness.
|
|
Naturally existing strains of Wolbachia have been shown to be a route for vector control strategies because of their presence in arthropod populations, such as mosquitoes. Due to the unique traits of Wolbachia that cause cytoplasmic incompatibility, some strains are useful to humans as a promoter of genetic drive within an insect population. Wolbachia-infected females are able to produce offspring with uninfected and infected males; however, uninfected females are only able to produce viable offspring with uninfected males. This gives infected females a reproductive advantage that is greater the higher the frequency of Wolbachia in the population.
|
|
The F-15s only flew over Minot until the spring of 1988, when the FIS was inactivated. The lynx den in the squadron was one of the few places where Canada lynx had bred in captivity in the U.S., prompting both the St. Louis and San Diego Zoos to copy it in an attempt to get their own lynx inhabitants to produce offspring. Several generations of lynx flourished there, and after the unit was inactivated, Delta and Dart, twin kitten descendants of the original two Lynx kitten mascots were donated to the Roosevelt Park Zoo in Minot.
|
|
Reciprocal crosses are included within the same grex. If two members of the same grex produce offspring, the offspring receive the same grex name as the parents. If a parent of a grex becomes a synonym, any grex names that were established by specifying the synonym are not necessarily discarded; the grex name that was published first is used (the Principle of Priority). All of the members of a specific grex may be loosely thought of as "sister plants", and just like the brothers and sisters of any family, may share many traits or look quite different from one another.
|
|
The best sperm competitors will less likely be inclined to care for their offspring upon mating because they have the ability to produce offspring elsewhere. Males with the greatest size, strength, or best developed weapons achieve the greatest mating success. In other cases, males may have a higher reproductive success if they have better access to resources than other competitors. For instance, female hanging flies mate with a male only if he provides a large insect for her to eat during copulation and North American bullfrogs protect ponds and small lakes where females come to lay their eggs.
|
|
The differing preferences is affected by the body size of the females, potentially due to body size being an indicator of fecundity, which is the ability to produce offspring. Blue breast males prefer conspecifics over red cheek females that are smaller; however, have a weaker preference for conspecifics over blue breast females that are only slightly smaller. Red cheek males have no preference for conspecifics in the presence of a larger blue breast female or blue cap female. Blue cap males prefer conspecifics over red cheek females; however, have no preference for conspecifics in the presence of a larger blue breast male.
|
|
A 1995 study at the University of Bern showed that women appear to be attracted to the smell of men who have different MHC profiles from their own, and that oral contraceptives reversed this effect. The MHC is a region of the human genome involved with immune function. Because parents with more diverse MHC profiles would be expected to produce offspring with stronger immune systems, dissimilar MHC may play a role in sexual selection. A speed "date" lasting several minutes should be long enough for the MHC hypothesis to come into play, provided the participants are seated close enough together.
|
|
In Brazil, tambaqui is one of the main fish species that is farmed and therefore important to the country's economy. Studies of farmed tambaqui in Brazil have revealed a genetic diversity similar to that seen among wild populations. In fish farms this species is sometimes hybridized with Piaractus to produce offspring that accept a wider temperature range (colder water) than pure tambaqui. In Thailand, this fish, known locally as pla khu dam (ปลาคู้ดำ), was introduced from Hong Kong and Singapore as part of fish- farming projects, but has adapted to local conditions and thrives in the wild in some areas.
|
|
In 1484, he took as his second wife, Catherine Plantagenet, the illegitimate daughter of King Richard III; however, this marriage failed to produce offspring. Ultimately, Herbert only had one child, a daughter by his first marriage, Elizabeth Herbert, 3rd Baroness Herbert, who later married Charles Somerset, later Earl of Worcester. Elizabeth was of great importance to the Somerset family, as she brought to them wealth and a legitimate relationship to royalty. The barony of Herbert was created by patent in favour of her husband, although during her lifetime she held the barony of Herbert in her own right.
|
|
The humanoid Cylons are as biological as they are technological and can potentially mate with humans and produce offspring. This fact seems to be part of the "plan" of the Cylons who want to repopulate the human colonies with a new generation of hybrid beings. Once the Cylons learn of Athena's pregnancy, they decide the child must be protected at all costs and thus have impact on the Cylon agenda in pursuing the refugee fleet. Hera is believed to be the only successful hybrid born, which is believed to be due to the love between her parents.
|
|
5–8 (January 1950); followed by The wild type of this virus has a temperate life cycle that allows it to either reside within the genome of its host through lysogeny or enter into a lytic phase, during which it kills and lyses the cell to produce offspring. Lambda strains, mutated at specific sites, are unable to lysogenize cells; instead, they grow and enter the lytic cycle after superinfecting an already lysogenized cell. The phage particle consists of a head (also known as a capsid), a tail, and tail fibers (see image of virus below). The head contains the phage's double-strand linear DNA genome.
|
|
Reproductive isolation between species appears, in certain cases, a long time after fertilization and the formation of the zygote, as happens – for example – in the twin species Drosophila pavani and D. gaucha. The hybrids between both species are not sterile, in the sense that they produce viable gametes, ovules and spermatozoa. However, they cannot produce offspring as the sperm of the hybrid male do not survive in the semen receptors of the females, be they hybrids or from the parent lines. In the same way, the sperm of the males of the two parent species do not survive in the reproductive tract of the hybrid female.
|
|
Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the natural capability to produce offspring, measured by the number of gametes (eggs), seed set, or asexual propagules. A lack of fertility is infertility while a lack of fecundity would be called sterility. Human demography considers only human fecundity, at its culturally differing rates, while population biology studies all organisms. The term fecundity in population biology is often used to describe the rate of offspring production after one time step (often annual).
|
|
The Whitlams moved into the house around May 1915 and Edward Gough Whitlam was born on 11 July 1916, on the kitchen table according to family legend. Presumably Gough would have been conceived in the front bedroom of the house sometime around early October 1915. Fred and Mattie therefore were in the house no more than 5 months before their attempts to produce offspring were successful.National Trust Heritage Citation He was the older of two children (he had a younger sister, Freda) Fred Whitlam was working at this time in the Commonwealth Crown Solicitor's Office, in the Attorney General's Department, headed by Robert Garran.
|
|
Superfecundation is the fertilization of two or more ova from the same cycle by sperm from separate acts of sexual intercourse, which can lead to twin babies from two separate biological fathers. The term superfecundation is derived from fecund, meaning the ability to produce offspring. Homopaternal superfecundation refers to the fertilization of two separate ova from the same father, leading to fraternal twins; while heteropaternal superfecundation is referred to as a form of atypical twinning where, genetically, the twins are half siblings. Superfecundation, while rare, can occur through either a complex single occurrence of sexual intercourse, separate occurrences of sexual intercourse, or through artificial insemination.
|
|
According to the midrash, Hannah was Elkanah’s first wife; after they had been married for ten years, he also took Peninnah as a wife (Pesikta Rabbati 43). The midrash explains that Elkanah was compelled to marry Peninnah because of Hannah’s barrenness, which explains his preference for Hannah, his first wife. Another tradition has the initiative to marry Peninnah coming from Hannah, thus comparing her to Sarah and Hagar, and Rachel and Leah, in which the beloved wife, who is barren, initiates the taking of an additional wife in order to produce offspring. The different midrashim highlight the difficulty Peninnah faced living in the shadow of another woman.
|
|
Sexual selection preferences are general terms by which the mating and reproductive process are understood. As one article states, sexual selection is in essence a process which favors sexual displays for attraction, aggressiveness, dominance, size, and strength, and the ability to exclude competitors by force if necessary, or by using resources to win. Both male and female use voice, face, and other physical characteristics to assess a potential mate's ability to reproduce, as well as their health. Together with visual and chemical signals, these crucial characteristics which are likely to enhance the ability to produce offspring, as well as long term survival prospects, can be assessed and selections made.
|
|
The expectation that Frederick would not likely produce offspring, despite numerous affairs, was widespread, but sources rarely state the reasons. Some speculate that Frederick was infertile. During the reign of Frederick's father, Christian VIII, the succession question was already being brought forward. (See below: Succession crisis) It has recently been claimed that the king did indeed father a son, Frederik Carl Christian Poulsen, born on 21 November 1843, as a result of his relationship with Else Maria Guldborg Pedersen (also referred to as Marie Poulsen), which took place after his first two unhappy marriages. This was brought forward in a book published in 1994 and again in a book published in 2009.
|
|
As hinted at in chapter one, genes are the supreme lords of the natural world. In other words, the unit of selection is the gene, not an individual, or any other higher-order group as championed by proponents of group selection. As long as an organism survives its childhood and manages to reproduce thus passing its genes down to the next generation, what happens to the parent organism afterwards does not really bother genes. Because an organism is always at the danger of dying from accidents (a waste of investment), it pays for the genes to build an organism which pools almost all its resources to produce offspring as early as possible.
|
|
The Gleaner stated: "Judging by the reviews and pop culture references to his on stage character, Ramsey is a budding star with his delightful sense of comedic timing and delivery, razor sharp wit and gift of physical comedy." A two-month run was followed by a tour of the Jamaican and West Indian diaspora in the United States, Canada, and England. The play was succeeded by another roots play, Like Father, Like Son, and 2008 saw the debut of Di Driva, by Paul O'Beale, at the Green Gables Theatre, Cargill Avenue, St. Andrew. The play tells the story of a politician and his wife, a former beauty queen, and their unsuccessful attempts to produce offspring.
|
|
By using cells from a closely related species to the extinct species, genome editing can play a role in the de-extinction process. Germ cells may be edited directly, so that the egg and sperm produced by the extant parent species will produce offspring of the extinct species, or somatic cells may be edited and transferred via somatic cell nuclear transfer. This results in a hybrid between the two species, since it is not completely one animal. Because it is possible to sequence and assemble the genome of extinct organisms from highly degraded tissues, this technique enables scientists to pursue de-extinction in a wider array of species, including those for which no well-preserved remains exist.
|
|
I was not interested in action for its own sake. And I’ve never worked so hard in my life." Those who hold this interpretation argue that this aspect of Ozu's work gives it its universality, and helps it transcend the specifically Japanese cultural context in which the films were created. Bock writes: "The subject matter of the Ozu film is what faces all of us born of man and woman and going on to produce offspring of our own: the family… [The terms "shomingeki" or "home drama"] may be applied to Ozu’s works and create an illusion of peculiar Japaneseness, but in fact behind the words are the problems we all face in a life cycle.
|
|
Star Wars books and media outside the films have established that banthas are an integral part of the culture of Tusken Raiders on Tatooine, with a deep spiritual and emotional connection developing between each bantha and its Tusken rider. When a Tusken Raider reaches age seven, a bantha of the same gender is ceremonially presented to the child as its partner in life. The young Tusken cares for and raises the bantha as it grows, and once it reaches maturity, the Tusken rides it and takes it into the desert for initiatory ceremonies and tasks. When Tusken Raiders marry, the couple's banthas also mate, and when the Tusken couple has children the banthas will often produce offspring as well.
|
|
Eukaryote hybrid genomes result from interspecific hybridization, where closely related species mate and produce offspring with admixed genomes. The advent of large-scale genomic sequencing has shown that hybridization is common, and that it may represent an important source of novel variation. Although most interspecific hybrids are sterile or less fit than their parents, some may survive and reproduce, enabling the transfer of adaptive variants across the species boundary, and even result in the formation of novel evolutionary lineages. There are two main variants of hybrid species genomes: allopolyploid, which have one full chromosome set from each parent species, and homoploid, which are a mosaic of the parent species genomes with no increase in chromosome number.
|
|
Silene dioica, female flower Silene dioica male flowers (etamins) with anthers Silene noctiflora, male and female flowers Silene are a flowering plant that evolved a dioecious reproductive system. This is made possible through heteromorphic sex chromosomes expressed as XY. Silene recently evolved sex chromosomes 5-10 million years ago and are widely used by geneticists and biologists to study the mechanisms of sex determination since they are one of only 39 species across 14 families of angiosperm that possess sex-determining genes. Silene are studied because of their ability to produce offspring with a plethora of reproductive systems. The common inference drawn from such studies is that the sex of the offspring is determined by the Y chromosome.
|
|
These deities are initiation deities who select their worshipers according to various factors such as gender, martial prowess, ability for clairvoyance, etc. They include the Fawafa, the Python deity of men's initiations, Fakuntifa, the lizard deity of women's initiations, Fayenfe, the god of war and death, Litakon, the god of twins and fertility, Kupon, the deity of divination, etc. These deities are better considered families of deities, or deity types, rather than unique deities: there are male and female Fawafa deities, for example, who are believed to produce offspring of their deity type. The Batammariba may acquire these deities by inheriting them from someone, hunting and capturing them in the wild, or by buying and selling them to and from their neighbors.
|
|
Rich argues that women feel pressure to be heterosexual in the workplace, and that this pressure is also present in society as a whole. As a species will become extinct if no reproduction occurs, and human women must be inseminated to produce offspring, heterosexual relationships are necessary for the survival of the human race, barring artificial insemination. According to Rich, women accept the male sex drive and regard themselves as sexual prey, and this influences compulsory heterosexuality. Furthermore, according to Rich, Barry argues for a "sexual domination perspective", claims that men subject women to what she terms as "sexual abuse" and "terrorism", and that the "sexual domination perspective" causes people to consider this "sexual abuse" and "terrorism" to be natural and inevitable and thus ignore it.
|
|
Women’s preferences for body odor change with their menstrual cycles. The ovulatory-shift hypothesis argues that women experience elevated immediate sexual attraction, relative to low-fertile days of the cycle, to men with characteristics that reflect good genetic quality. Body odor may provide significant cues about a potential sexual partner's genetic quality, reproductive status, and health, with a woman's preferences for particular body odors becoming heightened during her most fertile days. As certain body odors can reflect good genetic quality, woman are more likely to prefer these scents when they are fertile, as this is when they are most likely to produce offspring with any potential mates, with conception-risk being related to a preference for the scent of male symmetry.
|
|
A niche: the place where a statue may stand The ecological meaning of niche comes from the meaning of niche as a recess in a wall for a statue, which itself is probably derived from the Middle French word nicher, meaning to nest. The term was coined by the naturalist Roswell Hill Johnson but Joseph Grinnell was probably the first to use it in a research program in 1917, in his paper "The niche relationships of the California Thrasher". The Grinnellian niche concept embodies the idea that the niche of a species is determined by the habitat in which it lives and its accompanying behavioral adaptations. In other words, the niche is the sum of the habitat requirements and behaviors that allow a species to persist and produce offspring.
|
|
If the breeding is for a purebred animal that will be used for exhibition or future breeding (pets or livestock), the animal must be registered and conform to the criteria laid out for that breed in a breed standard kept by a central authority, such as a kennel club for dogs. In addition, the breed club, kennel club, or other governing authority may have other restrictions on the type of animal that can be used for breeding to produce offspring that can be registered. For example, some equine societies allow backbred and crossbred individuals to be bred from; most dog clubs do not except in exceptional circumstances, by permission. Most kennel clubs allow any registered individual to be bred from; the individual breed club may have additional, stricter criteria.
|
|
Aphids alternate between asexual reproduction in the Summer, i.e., when the environment is favorable and there is plenty of food, and sexually in the Fall when the organism is stressed by its environment. This has the biological advantage of ensuring identical copies of the parent will be well suited to take advantage of the favorable conditions, and variation in offspring in a stressful environment in hopes some of the offspring will find the environment favorable, even when the parents do not. The entire social construct in the novel is therefore an extrapolation of this idea onto a human culture, where successful female clans (female, because only they can produce offspring) can take advantage of their sociological niches by producing exact copies, and unsuccessful females produce variable offspring sexually.
|
|
Mating pair of Anisomorpha buprestoides The life cycle of the stick insect begins when the female deposits her eggs through one of these methods of oviposition: she will either flick her egg to the ground by a movement of the ovipositor or her entire abdomen, carefully place the eggs in the axils of the host plant, bury them in small pits in the soil, or stick the eggs to a substrate, usually a stem or leaf of the food plant. A single female lays from 100 to 1,200 eggs after mating, depending on the species. Many species of phasmids are parthenogenic, meaning the females lay eggs without needing to mate with males to produce offspring. Eggs from virgin mothers are entirely female and hatch into nymphs that are exact copies of their mothers.
|
|
In addition, a females ultimate reproductive success is limited due to ability to distribute her time and energy towards reproducing. Peter T. Ellison states, "The metabolic task of converting energy from the environment into viable offspring falls to the female, and the rate at which she can produce offspring is limited by the rate at which she can direct metabolic energy to the task" The reasoning for the transfer of energy from one category to another takes away from each individual category overall. For example, if a female has not reached menarche yet, she will only need to be focusing her energy into growth and maintenance because she cannot yet place energy towards reproducing. However, once a female is ready to begin putting forth energy into reproduction she will then have less energy to put towards overall growth and maintenance.
|
|
Since a daughter is not considered "a potential contributor to the lineage into which she is born," but rather "it is expected that she will give the children she bears and her adult labor to the family of her husband," the wife of a deceased son would benefit her husband's family by becoming a caregiver in their home. Once the deceased son had a wife, the family could adopt an heir, or a "grandson", to continue on the family line. The purpose of the daughter- in-law was not to produce offspring, as she was to live a chaste life, but she became the "social instrument" to enable the family to adopt. The family preferred to adopt patrilineally related male kin, usually through a brother assigning one of his own sons to the lineage of the deceased.
|
|
Water is an excellent solvent and has two other useful properties: the fact that ice floats enables aquatic organisms to survive beneath it in winter; and its molecules have electrically negative and positive ends, which enables it to form a wider range of compounds than other solvents can. Other good solvents, such as ammonia, are liquid only at such low temperatures that chemical reactions may be too slow to sustain life, and lack water's other advantages. Organisms based on alternative biochemistry may, however, be possible on other planets. Research on how life might have emerged from non-living chemicals focuses on three possible starting points: self-replication, an organism's ability to produce offspring that are very similar to itself; metabolism, its ability to feed and repair itself; and external cell membranes, which allow food to enter and waste products to leave, but exclude unwanted substances.
|
|
While it is often assumed that parthenogenesis is an inferior evolutionary strategy to sexual reproduction because parthenogenetic species lack the ability to complement genetic mutations through outcrossing or are unable to incorporate new genetic material, research on parthenogenetic species has gradually revealed a number of advantages to this mode of reproduction. Triploid unisexual geckos of the species Heteronotia binoei have greater endurance and aerobic capacity than their diploid ancestors, and this advantage may be the result of polyploidy and a form of hybrid vigor. It has also been observed that obligate parthenotes are often found at high altitudes and in sparse or marginal habitats, a pattern known as "geographical parthenogenesis," and their distribution in suboptimal territories may be a result of their increased colonization ability. A single parthenogenetic individual can colonize a new territory and produce offspring, while for a sexual species multiple individuals would need to occupy a new habitat and come into contact with each other for mating in order for successful colonization to occur.
|
|
The maintenance of sexual reproduction (specifically, of its dioecious form) by natural selection in a highly competitive world has long been one of the major mysteries of biology, since both other known mechanisms of reproduction – asexual reproduction and hermaphroditism – possess apparent advantages over it. Asexual reproduction can proceed by budding, fission, or spore formation and does not involve the union of gametes, which accordingly results in a much faster rate of reproduction compared to sexual reproduction, where 50% of offspring are males and unable to produce offspring themselves. In hermaphroditic reproduction, each of the two parent organisms required for the formation of a zygote can provide either the male or the female gamete, which leads to advantages in both size and genetic variance of a population. Sexual reproduction therefore must offer significant fitness advantages because, despite the two-fold cost of sex (see below), it dominates among multicellular forms of life, implying that the fitness of offspring produced by sexual processes outweighs the costs.
|
|
She maintained that while many accusations against them were false, their scholarship was questionable, and they underestimated the importance of non-sexual motivations of rape. She wrote that they misused data to try to support their predictions about the "degree of psychological pain experienced by rape victims", and was unconvinced by their response to the charge. Baxi, writing in 2014, described the book as being part of "a recent resurgence of biological and evolutionary theories of rape", and endorsed the opinion of a critic who maintained that it amounted to "an incitement to rape" by suggesting that rape is an "unchangeable" form of behavior. Thornhill and Palmer, writing in Psychology, Evolution & Gender, wrote that A Natural History of Rape had been criticized by "social constructionists", and that media accounts and reviews of the book misunderstood and misrepresented it, falsely ascribing to them views such as that "rape is good", that rapists are not responsible for their behavior, that "all men will rape", that rapists are driven by "desire to produce offspring" rather than desire for sexual stimulation, and that victims should be blamed.
|
|
Mate desertion involves the decision by an already-mated individual to either continue providing parental care or to desert. In making this decision, a parent must balance investment in terms of current and future reproductive success, choosing the optimal strategy, or one that provides the greatest net benefit towards lifetime reproductive success. Current success is measured by the number of surviving offspring, whereas future success is measured by the potential to successfully produce offspring in future seasons. These trade-offs between costs and benefits are further reflected in the two major conflicts driving mate desertion: 1) parent-offspring conflict over the level of parental investment that a parent should provide and 2) sexual conflict between mates over who should provide care and how much care should be provided. According to evolutionary biologist Robert Trivers, parental investment is defined as “any investment by the parent in an individual offspring that increases the offspring's chance of surviving (and hence reproductive success) at the cost of the parent's ability to invest in other offspring.” This investment includes investing in gametes and feeding and protecting young, which is also known as brooding.
|
|