Alternative reproductive strategies, Lecture 12

Question 1

Alternative reproductive strategies

Answer 1

Individuals of some species have different reproductive behaviours

Question 2

If selection maximises lifetime reproductive success, how can two strategies evolve?
eg: Natterjack toads

Answer 2

1. males call to attract females to mating pools
2. females follow a sound gradient towards the pool
3. larger males make louder calls - tend to mate first
4. non- calling males act as silent satellites
5. satellites intercept some of the arriving females

Question 3

Why are callers and satellites different in Natterjack toads?

Answer 3

callers are larger, small males can’t out-croak them
satellites are younger, size increases with age,
so next year they will be callers,
not a genetic difference