Chapter 6 - Coyne.
1. What are sexual dimorphisms?
2. What problem do costly male, secondary sex traits pose for evolution?
3. What is sexual selection? Does it differ from natural selection?
4. Coyne discusses two different mechanisms for sexual selection. What are they?
5. What's the story behind the northern elephant seal?
6. What happened to male red-winged black birds when experimenters removed
their epaulets by painting them black?
7. What is post-mating competition? What types of traits/behaviors are
attributable to selection via post-mating competition?
8. What experiment did they perform with peacocks to examine female mate
choice? What experiment was done in long-tailed widow birds?
9. What is the two-fold cost of sex? Why should it favor asexually reproducing
species?
10. What hypotheses are out there to explain the evolution of sex?
11. What's the difference in humans between the maximum known number of
offspring for a female versus a male?
12. Here's one of my favorite evolution questions for an I-clicker.
The graphs above show the reproductive success for phalaropes (females compete
for males who take care of the eggs, peacocks (one male mates with many females),
and blue-footed boobies which are monogamous. Which graph refers to which bird?
How did you make your choice?
Second question, why do males and females have - on average - equal reproductive
success?
13. Why do we see reversed sexual dimorphisms in seahorses, pipefish, and
phalaropes?
14. Why do females choose males with extravagant ornaments? If these decrease
male survival (and the traits are heritable), then her sons will also have to express
these costly traits. Why not pick the dull colored guy? Coyne offers three reasons
why females may evolve certain preferences. What are they?