Question 18 The diagram shows a population of fish species that live in a river ecosystem. A small part of the population is geographically isolated from the rest of the population when a dam is built. The diagram shows the population 100 years after the dam was constructed. Which statement BEST describes what would occur between the populations if the dam were removed? a The two populations would not be able to reproduce with each other because they became two different species. b The two populations would be able to reproduce with each other because they have a common ancestor. c The two populations would be able to reproduce with each other because they have the same resources available. d The two populations would not be able to reproduce with each other because they have different appearances.