Flashcards in Fisher sex ratios Deck (5)
What did Blows et al. (1999) do?
Observed convergence onto 1:1 sex ratio in D. serrate and D. birchii hybrids. Created 30 hybrid lines with female-biased progeny, allowed to evolve for 16 generations, sex ratio moved back to 1:1
In Red Deer the birth ratio is often female-biased as males die in utero. Who found this and how is it corrected for?
Clutton-Brock et al. (1981)
Feeding rate is male-biased, more investment in male offspring
Who described differential pay-offs in Red Deer, and what did they say?
Krebs, Davies and West (2012)
Males are more expensive so dominant females have sons as they can direct more resources into them. Females are less expensive so lower ranking females produce daughters as they have less resources to give them.
What did Komdeur et al. (1997) find?
Parents can control the sex ratio. In Seychelles warblers female offspring will stay and help by bringing food to the nest. In goods territories broods are female-biased, in bad territories they are male-biased as females drain resources.