Seemingly dissimilar organisms such as hummingbirds, humans, and whales have similar skeletal structures. This most directly suggested to biologists that __________.

• A. only the best-adapted organisms can survive
• B. advantageous changes can be passed along to offspring
• C. most evolution occurs rapidly following a mass extinction
• D. All of the listed responses are correct.
• E. dissimilar organisms might have evolved from a distant, common ancestor

Answer: (E)

Verified step by step guidance

1. Begin by understanding the concept of homologous structures, which are anatomical features in different species that have a similar structure but may serve different functions. This suggests a common ancestry.
2. Consider the evolutionary principle that organisms with similar structures likely share a common ancestor. This is because these structures have been inherited from that ancestor and modified over time.
3. Analyze the given organisms: hummingbirds, humans, and whales. Despite their differences in appearance and lifestyle, they share similar skeletal structures, indicating a shared evolutionary origin.
4. Evaluate the options provided in the problem. The presence of similar skeletal structures does not directly suggest rapid evolution after mass extinction or that only the best-adapted organisms survive. Instead, it points to a common ancestry.
5. Conclude that the most direct implication of similar skeletal structures in dissimilar organisms is that they might have evolved from a distant, common ancestor, which is a fundamental concept in evolutionary biology.