Question

4/10
how do homologous structures provide evidence for common ancestry?
they have similar structures but different functions.
they are identical in all species.
they evolved independently in each species.

Explanation:

Homologous structures are anatomical features in different species that have a similar underlying structure (derived from a common ancestor) but may have different functions. For example, the forelimbs of humans, bats, and whales have similar bone arrangements (humerus, radius, ulna, carpals, metacarpals, phalanges). This similarity in structure (not function) indicates that these species shared a common ancestor. Over time, as species diverged and adapted to different environments, these structures evolved different functions (e.g., grasping for humans, flying for bats, swimming for whales). The key is the structural similarity due to common ancestry, not functional identity or independent evolution.

Answer:

They have similar structures but different functions.