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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, [1] [2] [3] the natural capability to produce offspring, [4] measured by the number of gametes (eggs), seed set, or asexual ...
Fecundity selection, also known as fertility selection, is the fitness advantage resulting from selection on traits that increases the number of offspring (i.e. fecundity). [1] Charles Darwin formulated the theory of fecundity selection between 1871 and 1874 to explain the widespread evolution of female-biased sexual size dimorphism (SSD ...
In medicine, the definition of fertility is "the capacity to establish a clinical pregnancy." [24] Women have hormonal cycles which determine when they can achieve pregnancy. The cycle is approximately twenty-eight days long, with a fertile period of five days per cycle, but can deviate greatly from this norm.
To test this hypothesis, red jungle-fowl males were infected with a parasitic roundworm and monitored for growth and developmental changes. Female preference was also evaluated. The researchers found that parasites affected the development and final appearance of ornamental traits and that females preferred males who were not infected.
A theory to explain the fertility-intelligence relationship is that while income and IQ are positively correlated, [35] income is also in itself a fertility factor that correlates inversely with fertility, that is, the higher the incomes, the lower the fertility rates and vice versa.
Sexual selection is an evolutionary concept that has been used to explain why, in some species, male and female individuals behave differently in selecting mates. In 1930, Ronald Fisher wrote The Genetical Theory of Natural Selection, [3] in which he introduced the modern concept of parental investment, introduced the sexy son hypothesis, and introduced Fisher's principle.
Bateman initially saw his study on Drosophila to be a test of Charles Darwin's doctrine of sexual selection, [2] which he saw not as flawed, but as incomplete. He felt that if he were to provide a concrete demonstration of how sexual selection played a role in the reproductive success of certain species, he could explain the gap between Darwin ...
Prenatal and perinatal psychology are often discussed together to group the period during pregnancy, childbirth, and through the early stages of infancy. The role of prenatal and perinatal psychology is to explain the experience and behavior of the individual before birth , postnatal consequences, and the lasting effects on development that ...