Final answer:
The correct option in the final answer is c. A pattern of nested sets of traits among organisms supports the concept of descent with modification from a common ancestor, which is central to Darwin's theory of evolution, demonstrating how species diversify and evolve from a common lineage.
Step-by-step explanation:
A pattern of nested sets of traits in a group of organisms supports the idea of descent with modification from a common ancestor. When examining the phylogenetic tree of life, we observe that organisms evolve from common ancestors and then diversify, showcasing both shared characteristics and genetic codes. This concept, which was one of the key insights of Charles Darwin's theory of evolution, suggests that all life on Earth shares a common origin and that differences among species arise due to mutations and natural selection over time.
The observation of an Archaeopteryx fossil, which presents features common to both reptiles and birds, underscores the principle of common descent. It highlights that modern species have inherited characteristics from ancestors while also acquiring new traits through evolutionary processes. According to the pattern of descent with modification, once a new trait becomes prevalent within a group, it leads to diversification and the emergence of new species as variations continue to arise, with some being adaptive and persisting.
In summary, descent with modification explains the unity and diversity of life by illustrating how organisms have evolved and diversified from a shared ancestral line. It is the foundation of modern evolutionary biology that emphasizes the genetic changes and appearance of new traits over generations, leading to the formation of different species from common ancestors.