Why would females choose “flashy”?

Gray tree frogs

Do long calls indicate good genes?

Do long calls indicate good genes? yes

Runaway sexual selection?

Fisherian Runaway Selection

The notion that sexual selection is more rapid than natural selectionand that it can lead to evolution of great extravagances that are detrimental

Male red-collared widow bird

Antlers are secondary sexual characteristics…

Use varies by species:Visual display of dominanceFightingMate attraction

Extinct 11,000 years ago

Irish Elk—extinctCrazy-big antlers, right? “Runaway Sexual Selection”?Or not…

http://eebweb.arizona.edu/animal_behavior/chase/chaseaway2a.htm

˄ Why the Irish Elk went extinct…Not

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 bodiesRunaway sexual selection could not have been

the cause of their extinction!

Endler ExperimentWithout predator, sexual selection is the driving force

Endler ExperimentWith predator, sexual selection is tempered

Discussion

Why are females often drab?

Why don’t males prefer flashy females?