Give two examples of evidence scientists use to show that life changes over time.

Enter your answer in the space provided

Evolution is evidence that life changes over time and an example is the Blue Moon Butterfly of the Samoan islands was being attacked by a parasite which destroyed male embryos. This led to a gender imbalance whereby males made up only 1% of the butterfly population. However, within ten generations (~1 year) males had returned to 40% of the population. This is not because the parasite has disappeared, it is still present, but it is no longer deadly to male embryos. This case shows how a mutation giving an advantage can rapidly spread throughout a population. Any male with the ability to survive infection would be able to mate with a great many females, due to the paucity of other males, and spread his immunity through the gene pool.

Fossils are also evidence that life changes over time and the evidence is that paleontologists and zoologists have long accepted that birds and reptiles are related. The two groups share many common traits including many skeletal features, the laying of shelled eggs, and the possession of scales, although in birds, scales are limited to the legs. Among modern birds, the embryos even have rudimentary fingers on their wings. In one modern bird, the South American hoatzin the wings of the juvenile have large moveable claws on the first and second digits. The young bird uses these claws to grasp branches.