• Question: What proof do we have that evolution exists?

    Asked by harrystylesgirlfriend to Mike, Pip, Tim, Tom on 4 Jul 2012.
    • Photo: Tim Stephens

      Tim Stephens answered on 4 Jul 2012:

      Great question.

      We’ve got fossil records that show different stages of the evolution of different animals, and the scientists who study these are able to link them together.

      We’ve got evidence in the form of animals that exist on different continents, but have the same ancestors (because the continents were once connected before the tectonic plates moved apart), and we can link them together because of their DNA fingerprints.

      Erm, that’s all I know since I’ve never really studied this field but I bet your biology teachers know some more!

    • Photo: Tom Lister

      Tom Lister answered on 4 Jul 2012:

      Seeing is believing, and there is plenty of visible evidence of evolution. There are different theories suggesting how evolution happens, most notably natural selection, artificial selection and sexual selection.

      Humans have understood artificial selection for years, and we see it all around us. It’s how we have so many breeds of domesticated dog, or varieties of vegetable and garden flowers. We carefully pick the parents and see their ‘good’ genes passed on to their offspring. Over many generations, there can be great changes – our agricultural crops bear little resemblance to their wild ancestors.

      Evolution can be seen even faster than this, within fractions of our lifetimes. For example, insects pests can quickly develop resistance to pesticides, and the story is always the same. When a new insecticide is used, many insects are killed by the poison, but often some survivors remain. The healthy insects may have something about them, a ‘trait’, which helped them to beat the poison. They go on to reproduce, and their offspring have a higher chance of survival. This is good for pesticide companies, because you always have to buy their new product!

      A last point I will mention is the similarities in different groups of animals, such as the skeletal structure of limbs in mammals. Bats, whales, cats and humans all have the same basic structure of their limbs which suggests a common ancestor. Some snakes have the vestigial remains of a pelvis, and we have the stump of a tail (coccyx).

Comments