Figure 3: Size‐specific sensitivity of the Trivers–Willard effect to a 1% increase in male mortality in bighorn sheep lambs. Our results show that in order to conclude that females are ...

In 1973, Trivers teamed up with a mathematician, Dan E. Willard, to formulate one of the most celebrated principles in evolutionary biology, called the Trivers-Willard hypothesis. The hypothesis ...

The Trivers-Willard hypothesis was proposed by American biologist Robert Trivers and American mathematician Dan Willard in their 1973 paper “Natural selection of parental ability to vary the sex ...

In an earlier post, I explain that the logic of the generalized Trivers-Willard hypothesis (gTWH) leads to the prediction that physically more attractive parents are more likely to have daughters ...

In 1973 biologist Robert Trivers and computer scientist Dan Willard published a paper suggesting that parents invest more resources, such as food and effort, in male offspring when times are good ...

Together the studies provide support for a 40-year-old theory in evolutionary biology. The Trivers-Willard hypothesis states that natural selection favors parental investment in daughters when ...

That’s the basis of the controversial Trivers-Willard hypothesis, which has shown mixed results across different species and studies. Another rationale for the increase in baby boys is that ...

In 1973, the biologist Robert Trivers and the computer scientist Dan Willard made a striking prediction about parents and their offspring. According to the principles of evolutionary theory ...

Often, they invest more in one sex than the other. The most famous explanation for this pattern was proposed by Robert Trivers and Dan Willard. They argued that females in rude health should ...