Question

From Amphibian on, the skeletal structure of Animals show "homologous" structures. What are homologous structures?

a) Homologous structures are different, so different that it points to a separate evolutionary path.
b) Homologous structures are structures that are so similar and shows that animals share a common ancestor
c) Homologous structures are structures that are exactly the same and show that the animals have the same parents.
d) All of the above

Answer 1

Homologous structures are anatomical features that originate from a common ancestor and can have different functions in descendants, unlike analogous structures, which are similar due to convergent evolution but not shared ancestry.

Step-by-step explanation:

Homologous structures are anatomical features in different species that share a common evolutionary origin, implying that these species have a common ancestor. These structures may have different functions but exhibit a similar underlying morphology. For instance, the bone structure in the limbs of various mammals like bats, humans, and whales is homologous because all these species inherited this pattern from a common ancestor. However, over time, they have evolved to fulfill different roles, such as flying, walking, or swimming.

It is crucial to note that homologous features are distinct from analogous structures, which arise due to convergent evolution where different species evolve similar traits independently, often due to similar environmental challenges or lifestyles. An example of analogous structures would be the wings of birds and butterflies. While both wings serve the function of flight, they do not share a common origin as in the case of homologous structures.