Question
A species of brown bear in Russia and the brown bear in the United States have a common ancestor. How did speciation produce these different brown bears?
Mutations and asexual reproduction.
Mutations and genetic recombination.
The development of structures for climbing trees.
The inheritance of acquired traits.
Mutations and asexual reproduction.
Mutations and genetic recombination.
The development of structures for climbing trees.
The inheritance of acquired traits.
Answers
GPT-4o mini
Speciation in the case of the brown bear in Russia and the brown bear in the United States is primarily driven by **mutations and genetic recombination**.
When populations of a species become geographically isolated (for example, through environmental changes or migration), they experience different selective pressures and mutations accumulate over time. Genetic recombination during reproduction also contributes to this genetic diversity. As these populations adapt to their respective environments and accumulate genetic differences, they may eventually diverge to the point where they can no longer interbreed, resulting in the formation of distinct species.
The other options listed, such as asexual reproduction, the development of structures for climbing trees, and the inheritance of acquired traits, do not appropriately describe the primary mechanisms that lead to speciation in this context. Asexual reproduction does not apply to bears, and the inheritance of acquired traits is not supported by modern evolutionary biology. Thus, the correct answer is mutations and genetic recombination.
When populations of a species become geographically isolated (for example, through environmental changes or migration), they experience different selective pressures and mutations accumulate over time. Genetic recombination during reproduction also contributes to this genetic diversity. As these populations adapt to their respective environments and accumulate genetic differences, they may eventually diverge to the point where they can no longer interbreed, resulting in the formation of distinct species.
The other options listed, such as asexual reproduction, the development of structures for climbing trees, and the inheritance of acquired traits, do not appropriately describe the primary mechanisms that lead to speciation in this context. Asexual reproduction does not apply to bears, and the inheritance of acquired traits is not supported by modern evolutionary biology. Thus, the correct answer is mutations and genetic recombination.