1. what evidence supports the common ancestry of humans and chimpanzees?

I do agree with that, scientists claim that evolution was how Homo sapiens branched off of the genus Homo. There is evidence to evolution, though.
The first is a cladogram, which shows evolutionary relatedness based on ancestral traits and derived traits. So bones and teeth for the ancestral. That would definitely show relatedness between humans and chimpanzees.
The next is a fossil, which is used to identify organisms and place them on cladograms.

The gens present in the dna in the nucleus of the cell in the body