The answer is either A, the bottleneck effect or C, natural selection. The answer is most likely A because it is hinted that the predator fish was placed in the isolated stream. The predators eating the darters less than 5cm is natural selection though.
Answer:
An ecological community is made up of all the populations of all the different species that live together in a particular area. The interactions between different species in a community are called interspecific interactions, inter- means "between".
During the rock cycle igneous rock is weather into metamorphic rock