Midterm1_3

Midterm1_3 - Evolution of Social Behavior Sexual Selection...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Evolution of Social Behavior I. Sexual Selection a. Selection for mating success b. May oppose natural selection c. May lead to sexual dimorphism Asymmetries in sexual reproduction - Females typically have larger parental investment (“sperm is cheap”) - Female reproductive success low and stable—limited by number of pregnancies she can carry - Male reproductive success highly variable—limited by number of successful matings - Asymmetric sexual reproduction in newts: more important for males to have more mates than females Sex roles reversed in some species - In seahorses and pipefish, males carry young in pouch and provide all parental care - When parental investment reverses, asymmetries in mating and reproduction also change - In pipefish, having more mates is more important for females than males - When parental investment roles are reversed, other traits reverse 1. Female pipefish more brightly colored, more competitive; Males choosy, prefer larger females 2. Phalaropes: Parental care by males; females more
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 2

Midterm1_3 - Evolution of Social Behavior Sexual Selection...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online