Trivers-Willard hypothesis

In evolutionary biology, the Trivers-Willard hypothesis proposes that parents should invest more in the sex that gives them the greatest reproductive payoff (grandchildren) with increasing or "marginal" investment. The hypothesis was used to explain why Red Deer mothers would produce more sons when they are in good condition, and more daughers when in poor condition.

Dominance also affects the sex of their offspring, with dominant females birthing more sons and non-dominant females birthing more daughters.