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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 ...
Women who married at age 25–29 years had a mean of 5.7 children and 5.0% remained childless. Women who married at 30–34 years had a mean of 4.0 children and 8.2% remained childless. [ 20 ] The average age at last birth in natural fertility populations that have been studied is around 40.
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.
This is an accepted version of this page This is the latest accepted revision, reviewed on 3 February 2025. Procreative biological processes of humanity Part of a series on Sex Biological terms Sexual dimorphism Sexual differentiation Feminization Virilization Sex-determination system XY XO ZW ZO Temperature-dependent Haplodiploidy Heterogametic sex Homogametic sex Sex chromosome X chromosome ...
This is an accepted version of this page This is the latest accepted revision, reviewed on 4 February 2025. Union of opposite-sex gametes in sexual reproduction to form a zygote This article is about fertilisation in animals and plants. For fertilisation in humans specifically, see Human fertilization. For soil improvement, see Fertilizer. "Conceive" redirects here. For the health magazine ...
There is little advantage in adaptations that permit successful competition with other organisms, because the environment is likely to change again. Among the traits that are thought to characterize r-selection are high fecundity, small body size, early maturity onset, short generation time, and the ability to disperse offspring widely.
In biology, the gonadosomatic index (GSI) is the calculation of the gonad mass as a proportion of the total body mass. It is represented by the formula: [1] GSI = [gonad weight / total tissue weight] × 100. It is a tool for measuring the sexual maturity of animals in correlation to ovary development and testicle development. The index is ...