Final answer:
Homologous structures indicate common ancestry and are crucial for constructing phylogenetic trees, while analogous structures result from convergent evolution but don't indicate a common ancestry. Biologists value homologous structures more for studying evolutionary relationships.
Step-by-step explanation:
The difference between homologous and analogous structures lies in their origin and function. Homologous structures have a similar embryonic origin and may or may not have a similar function, indicating a common ancestry. For instance, the bone structure in the limbs of mammals such as humans, bats, and whales suggests a common ancestor, despite these limbs serving various functions like grasping, flying, or swimming. Conversely, analogous structures perform similar functions but do not share a common embryonic origin, implying that they arose independently due to convergent evolution, such as the wings of butterflies and birds.
Biologists often consider homologous structures more critical since they provide insights into evolutionary relationships and common descent, which are essential when constructing phylogenetic trees. These evolutionary trees help scientists understand the lineage and historical connections among different species. Conversely, analogous structures result from convergent evolution and can be misleading when determining phylogenetic relationships.
Answering the multiple choice question provided, the correct option is 'd': Things that are analogous result from convergence and things that are homologous result from common ancestry.