Animal Behavior Lecture 3

This set of flashcards covers key concepts in animal behavior, focusing on sexual selection, mating systems, and parental investment.

Gametes

The haploid cells that join to form a diploid zygote, which then develops into an organism.

Isogamy

All gametes are the same size.

Anisogamy

Two kinds of gametes.

Sperm

Small, numerous, motile gametes produced by males.

Eggs

Large, less numerous, usually non-motile gametes produced by females.

Female fitness

Not limited by sperm numbers; enough sperm exists to fertilize all eggs.

Male fitness

Limited by egg numbers; males need to find females whose eggs they can fertilize.

Bateman's principle

Male fitness is primarily limited by access to females, while female fitness is limited by egg production.

Sexual selection

Selection acting on variation among members of one sex in their abilities to obtain fertilizations of the gametes of the other sex.

Intrasexual selection

Direct competition between members of the same sex to mate with members of the other sex.

Intersexual selection

Choice of a mating partner of the opposite sex by one sex, often forms of female choice.

Monogamy

One male mates with one female.

Polygyny

One male mates with more than one female.

Polyandry

More than one male mates with one female.

Lek polygyny

Males gather in groups on 'display grounds' and females come to mate.

Paternity assurance

Females are assured maternity, but males may not be assured of paternity.

Hamilton's rule

If the benefit provided to other individuals, scaled by r, is greater than the cost to self, then such 'sacrificial' behavior can evolve.