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Sexual selection in birds. Male greater frigatebird displaying. Sexual selection in birds concerns how birds have evolved a variety of mating behaviors, with the peacock tail being perhaps the most famous example of sexual selection and the Fisherian runaway. Commonly occurring sexual dimorphisms such as size and color differences are ...
In bdelloid rotifers, females reproduce exclusively by parthenogenesis (obligate parthenogenesis), [52] while in monogonont rotifers, females can alternate between sexual and asexual reproduction (cyclical parthenogenesis). At least in one normally cyclical parthenogenetic species obligate parthenogenesis can be inherited: a recessive allele ...
e. The ZW sex-determination system is a chromosomal system that determines the sex of offspring in birds, some fish and crustaceans such as the giant river prawn, some insects (including butterflies and moths), the schistosome family of flatworms, and some reptiles, e.g. majority of snakes, lacertid lizards and monitors, including Komodo dragons.
Sexual selection creates colourful differences between sexes in Goldie's bird-of-paradise.Male above; female below. Painting by John Gerrard Keulemans.. Sexual selection is a mechanism of evolution in which members of one biological sex choose mates of the other sex to mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex ...
That’s because it takes time for birds to signal sexual maturity. Most songbirds reach this state after one year, but bald eagles can take as long as five years to attain full adult plumage.
Most birds reproduce earlier if spring comes earlier. Climate change makes it difficult to notice a connection between temperature and the time of reproduction. [further explanation needed] Visser et al. (2009) has attempted to find this connection with a 6-year-long experiment in great tits (Parus major). If spring comes three weeks early ...
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete (haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes . [1]
Copulation (zoology) In zoology, copulation is animal sexual behavior in which a male introduces sperm into the female's body, especially directly into her reproductive tract. [ 1 ][ 2 ] This is an aspect of mating.