Unit 3 Recall

evolutionary trap example

turtle hatching and going to light

polyandry example

o   Pipefish: male pregnancy similar to seahorses (who are monogamous)

§  Males provide parental care by carrying fertilized eggs in a brood pouch.

§  They are not monogamous because of population density. In dense populations, a female has a higher likelihood of encountering multiple males with available pouches

inclusive fitness example

worker honey bee

intrasexual selection on males example

male deer fighting

by product mutualism example

o   pied kingfishers: cooperative breeding (help given without direct reciprocation). During first year can be: 1. Helpers (bring fish to nestlings), or 2. Delayers (do not help). Primary helpers related to pair (higher investment to help), and secondary pairs are unrelated to breeding pair (less investment)

male parental care example

seahorses

lek example

sage grouse

eusociality example

ant

r-strategist

mouse

k-strategist

elephant

sexual conflict

ducks

handicap signal

peacock

intersexual selection on males

peacock

future direct benefits from cooperation

vampire bat

new environment hypothesis

a relatively recent evolutionary pressure, and host birds have not yet evolved the ability to recognize and reject foreign eggs

net benefit hypothesis

even if accepting a foreign egg imposes a cost, the cost of mistakenly rejecting one’s own egg (or attacking the wrong chick) may be higher

2 main features of evolution through natural selection that distinguish it form most other processes like competition

variation and heritability in traits and differential reproductive success from traits