**Title: Evolution of Dark Pocket Mice: Understanding Genetic Changes** **Introduction** In studying the evolutionary changes in populations, let's consider pocket mice, an example of a species that likely evolved from being light colored to darker hues. This adaptation is believed to have occurred recently in response to environmental pressures, especially in areas with dark lava flows. Understanding what factors led to this evolution can provide insights into the mechanisms of natural selection and evolution. **Multiple Choice Question:** It is likely that, ancestrally, pocket mice were light colored. The dark coloration evolved recently in populations on the young, dark lava flows. For the evolution of dark pocket mice to occur, there must have been ___________. - **A.** some individuals in the ancestral population that had mutations that made them darker than other individuals - **B.** a large population of dark pocket mice somewhere in the species range in the ancestral population - **C.** a mutation that turned all light colored mice into dark colored mice at once - **D.** a gradual darkening of light colored mice during their lifetime so that they could occupy the dark lava flow **Explanation:** - **Option A** suggests that mutations occurred in some individuals, leading to darker fur, providing a camouflage advantage in the dark lava environment. This is consistent with the concept of natural selection where advantageous traits increase survival and reproduction. - **Option B** proposes a pre-existing large dark population, which is less likely given the environmental conditions described. - **Option C** implies a sudden, simultaneous mutation in all members, which is biologically improbable due to the random nature of mutations. - **Option D** suggests an acquired characteristic during a single lifespan, which contradicts genetic inheritance principles, as traits are passed genetically rather than acquired. **Conclusion:** Understanding how species adapt to their environments can give us powerful insights into the processes driving evolution. In the case of the pocket mice, considering genetic mutations and natural selection offers the most plausible explanation for the observed evolutionary changes.

Which of the following scenarios shows the founder effect? O Two different species of frogs mate with each other and create a triploid hybrid. This hybrid can produce viable offspring via parthenogenesis OA small group of salamanders moves away from the large population. By chance, this newly established population contains only individuals with the same genetic mutation O Butterflies with a foul taste are left alone by predators, while those without the foul taste are eaten O An avalanche wiped out 90% of a snow hare population, by chance, only the dark brown hares survived O Cichlid fish in lake Tanganyika were under the influence of different microhabitats and evolved based on the local environmental conditions

1. What is the term describing the process that occurs when a species evolves into a new species with a physical barrier separating populations? a adaptive radiation . geographic isolation b. coevolution c. Geographic isolation d. Mutation

A small number of birds arrive on an island from a neighboring larger island. This small population begins to adapt to the new food plants available on the island, and their beaks begin to change. About twice a year, one or two more birds from the neighboring island arrive. What effect do these new arrivals have? O A. Their arrival represents a colonizing event. O B. Their arrival will likely prompt genetic drift. O C. Their arrival tends to retard adaptation to the new food plants. O D. Their arrival speeds the process of speciation. O E. Their arrival tends to promote adaptation to the new food plants.