Skip to main content

Questions tagged [sex-ratio]

the ratio of males to females in a population. Use this tag in questions related to sex ratio in a population or species, or regarding the principles and calculations about sex ratios.

Filter by
Sorted by
Tagged with
0 votes
0 answers
21 views

Fisher's principle in humans [duplicate]

Some research suggests that men have historically had far less reproductive success than women, even given the approximately 1:1 sex ratio in humans. However, doesn't Fisher's principle suggest that ...
user avatar
2 votes
1 answer
105 views

Evidence of condition-dependent sex-allocation in regards to humans

Coming from zero background in biology, I am looking for expert opinion on evidence regarding Trivers-Willard hypothesis (1973) and humans. In short the hypothesis states that if "Condition" of ...
snoram's user avatar
  • 163
7 votes
2 answers
277 views

Does knowing the sex of each of a couple’s first N children have any marginal value in predicting the sex of child N+1?

Does knowing the sex of each of a couple’s first N children have any marginal value in predicting the sex of child N+1? By “marginal” I mean predictive power beyond other known effects, e.g., the race ...
kuzzooroo's user avatar
  • 441
6 votes
2 answers
1k views

How can sex ratios remain Fisherian (1:1) in species where only the dominant male gets to mate

In certain species only the dominant male gets to mate (or given strong preference), and yet the sex ratio remains 1:1. (I'm thinking in particular of gorillas). How does this happen? It doesn't seem ...
pseudosudo's user avatar
1 vote
2 answers
3k views

In what animal species is the sex ratio skewed in favour of the fertile female?

Ants have something like a single fertile female to several males. The same applies to bees, and larger animals - elephants too. Is the sex ratio universally skewed in favour of the female? What ...
Everyone's user avatar
  • 3,863
19 votes
3 answers
656 views

Are human fetuses more likely to be male? [duplicate]

Question: From a physiological point of view, when sex is determined in a human fetus, is it equally likely to be male or female? Studies in this area typically measure age at birth, where the data ...
Douglas S. Stones's user avatar