Bgyb51: chapter 2 (pages 37 49 and 53 65) These muscles are effective for animals that are very hairy like chimpanzees. Most of us are not that hairy (except some of you hormone excessive freaks), and thus the result of these muscles contracting is goose bumps. This implies that we descended from ancestors who were hairier than us: read page 42 for more examples, vestigial traits also occur at a molecular level. Humans have one on chromosome 6; a dna sequence that looks like a gene for the enzyme cmah. It is actually disabled by a 92-base-pair deletion and humans cannot manufacture cmah. Fossil: a trace of any organism that lived in the past. Transitional species should show a mix of features of the. They do! ancestral population as well as novel traits of later descendants: a great example is the archaeopteryx. It was a birdlike creature with a dinosaurian appearance.