Imagine a situation much like the example of guppies in Trinidad and Tobago described in your text. In this situation, populations of guppies who once shared an evolutionary history have been separated by the for-mation of barrier waterfalls

Question

If you are an evolutionary biologist studying reproductive trade-offs, make a prediction about the reproduc-tive strategies you might find in female guppies found on each side of this barrier when the upstream side population faces lower predation than the downstream side. In this situation, the predators on the down-stream side are also larger and can eat any guppy offspring, no matter the size. Describe your predictions about how females on each side of this barrier might reproduce and explain the trade-offs faced by reproduc-ing females.

What will be an ideal response?

Answer 1

ANS:
Will vary, but could include: females at high predation sites mature faster and produce more smaller fry than their upstream counterpart. Trade-offs might include higher probability of larger offspring surviving in lower predation sites but each fry requires more of a female's resources, so fewer fry are produced. In high preda-tion sites, natural selection may favor the production of more but smaller fry.