Explain Fossil and Molecular Evidence Practice Test

A fossil sequence in older-to-younger rock layers shows:

1. reptiles with jaw bones adapted for chewing,

2. later fossils with smaller jaw bones and larger middle-ear bones,

3. mammals with three middle-ear bones and a single lower jaw bone.

What is the best explanation for how this fossil pattern supports evolution?

Two species have similar-looking body shapes due to living in similar environments, but their DNA sequences are much less similar than expected if they were close relatives. Which statement best explains how molecular evidence helps in this situation?