1. Why would females choose “flashy”?

2. Gray tree frogs

4. Do long calls indicate good genes?

5. Do long calls indicate good genes? yes

8. Runaway sexual selection?

9. Fisherian Runaway Selection The notion that sexual selection is more rapid than natural selection and that it can lead to evolution of great extravagances that are detrimental

10. Male red-collared widow bird

11. Antlers are secondary sexual characteristics… Use varies by species: Visual display of dominance Fighting Mate attraction Extinct 11,000 years ago

12. Irish Elk—extinct Crazy-big antlers, right? “Runaway Sexual Selection”? Or not…

13. http://eebweb.arizona.edu/animal_behavior/chase/chaseaway2a.htm ˄ Why the Irish Elk went extinct… Not

14. Note axes = log scale M = Megaloceros X axis = 200 mm increase Y axis = 1000 mm increase Not a 1:1 ratio of increase! Irish Elk had antlers exactly the right size for their bodies Runaway sexual selection could not have been the cause of their extinction!

15. Endler Experiment Without predator, sexual selection is the driving force

16. Endler Experiment With predator, sexual selection is tempered

17. Discussion Why are females often drab? Why don’t males prefer flashy females?