Search results
Results from the WOW.Com Content Network
The minimum cost of breeding for a mare owner includes the stud fee, and the cost of proper nutrition, management and veterinary care of the mare throughout gestation, parturition, and care of both mare and foal up to the time of weaning. Veterinary expenses may be higher if specialized reproductive technologies are used or health complications ...
Elephants can use their ears as threat displays in male-to-male competition. Sexual selection in mammals is a process the study of which started with Charles Darwin's observations concerning sexual selection, including sexual selection in humans, and in other mammals, [1] consisting of male–male competition and mate choice that mold the development of future phenotypes in a population for a ...
A broodmare. Note slight distension of belly, indicating either early pregnancy or recent foaling. A mare is an adult female horse or other equine. [1] In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger.
The polygyny threshold model also shows the effects of female reproductive success when multiple females in the same territory mate with one male. In this situation, the female has the option of breeding with an unmated male in a poor-quality territory or with an already-mated male in a high-quality territory.
In support of the Charnov and Bull hypothesis, Warner and Shine (2008) showed confidently that incubation temperature influences males’ reproductive success differently than females in Jacky Dragon lizards (Amphibolurus muricatus) by treating the eggs with chemicals that interfere with steroid hormone biosynthesis. These chemicals block the ...
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 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 (intrasexual ...
Looking into the genetic determinants of human sex can have wide-ranging consequences. Scientists have been studying different sex determination systems in fruit flies and animal models to attempt an understanding of how the genetics of sexual differentiation can influence biological processes like reproduction, ageing [24] and disease.
By and large, a male's potential reproductive success is limited by the number of females he mates with, whereas a female's potential reproductive success is limited by how many eggs she can produce. According to Bateman's principle, this results in sexual selection , in which males compete with each other, and females become choosy in which ...