Question

State one reason why some species might have similar body structures even if they are not closely related.

Answer 1

Convergent evolution of unrelated species found in same habitat.

Step-by-step explanation:

The unrelated species found in the same habitat exhibit same morphological and functional adaptations to make them better adapted to the surroundings. hence, convergent evolution of unrelated species results in presence of similar body structure even if they are not closely related.

Example: Birds and bats have wings for flying (same body structure); though birds are aves while bats are mammals.

Answer 2

A reason would be the function: some body structures are good for some functions.

For example, a Giraffe is tall to be able to eat from the tree tops. Another animal might get a selective advantage of being tall and might develop a long neck, because the leaves from tree tops might support the taller individuals in survival.

So some structures are adaptive in some environments and might arise independently.