A scientist made the hypothesis: 'Organism B may have evolved from organism A.'
A scientist studies two fossils, Fossil A and Fossil B. Fossil A is found in a rock layer 50 metres deep. Fossil B is found in a rock layer 20 metres deep. Both fossils have similar body structures, but Fossil B has a more complex skeleton.
What two pieces of evidence support the scientist's hypothesis?

The fossil record provides strong evidence for evolution. 1. **Age of Fossils:** The principle of superposition states that in layers of sedimentary rock, the oldest layers are at the bottom and the youngest are at the top. Since Fossil A was found deeper (50m) than Fossil B (20m), Fossil A is older. This is consistent with it being an ancestor. 2. **Changes over Time:** Evolution by natural selection leads to gradual changes in species over millions of years. Often, this results in organisms becoming more complex or better adapted to their environment. The fact that the younger fossil (B) is more complex than the older, similar fossil (A) supports the hypothesis that B evolved from A.