For each missing word or phrase, circle the choice that correctly completes the sentence
The Devil's Hole water system is part of a large underground aquifer in Death
Valley National Park. After the last lce Age, around 10,000 years ago, as the
water dried up and the land tumed to desert, separate pools of water formed.
(Biomes / Species / Populations) of pupfish eventually became isolated in a
few of these water holes and springs and then evolved different (adaptive /
disruptive / stabilizing) traits to become distinct species over time. This kind of
(polygenic drift / genetic drift / environmental effect) likely occurred because
each water pool was inhabited by a few surviving individuals of the original larger
population. A change in (habitat conditions /
genetic equilibrium / allele frequency following a large reduction in
population size is called a (bottleneck effect/polvaenetic effect/
environmental effect)