25. the diagram below represents a section of undisturbed layers of sedimentary rock in new york state and shows the location of fossils of several closely related species. according to currently accepted evolutionary theory, which is the most probable assumption about species a, b, and c?

a. species b is more abundant than species c.
b. species c existed before species b.
c. species a and b are genetically identical.
d. species b descended from species a.
e. species c evolved from species b

B.Species C existed before species B.

Explanation:

Sedimentary rocks are true "history books" containing fossils of the species that have lived. Each layer represents a specific time period where the deeper the layer, the older it is. Thus, as seen in the diagram, Species C is the oldest of them all. Thus it existed before species B and could not evolve from it, just as species B could not be a descendant of species A. It cannot be determined from the diagram if species A and B are genetically identical (most probably not as they are two different species) or which species was most abundant of them all.