Question

Fossil X can be considered to have evolved earlier than fossil Y if

• A. Y has vestigial structures that are homologous to functional structures in fossil X.
• B. Y is structurally more of preservation than X.
• C. X is in better state of preservation than Y
• D. X is found in lower stratum of undisturbed sedimentary rock than Y.

Answer 1

Answer: (A)

Y has vestigial structures that are homologous to functional structures in fossil X.

Vestigial structures are the non-functional structures i.e., they have no apparent function. These are not functional in related animals but were functional in their ancestors. These structures suggest that the species has changed over time and descended from an ancestor with different ecological or genetic characteristics.

So, if fossil X is considered to be evolved earlier than Y, then Y could have vestigial structures that were functional in X, as Y descended from X and during this course of evolution, the functional structure in X became non-functional in Y.

So, the correct answer is A.