Biology 11 – Darwin and DNA –

The discovery of DNA proved Darwin’s theory of evolution for many reasons. Some of these reasons include, gene similarities in different species, and corrupt DNA. Genetic similarities in different species is very important, and was even mentioned in the NOVA video we watched in class. An example of genetic similarities would be the genetic relationship between human and chimp DNA. There is a 1% difference between human DNA and chimp DNA.

This means, that in some point in time there was a species that is now a common ancestor between humans and chimps. In the video, the species that was this connection is fish. Fish are a common ancestor with dinosaurs and all four legged creatures (for example humans and chimps). One visible similarity between humans and fish, is between human embryo and fish embryos, as was shown in the video. If you compare two images of a human and fish embryo, there are clearly slits (gills) along the neck of both species, for humans these slits (gills) turn into bones in our inner ears, and for fish, these slits turned into gills.

Corrupt DNA is also very important to Darwin’s theory. A big part of Darwin’s theory is that an organism changes into another organism. For this to happen, changes must also happen to a genome over time. Because of this, scientists are able to see relationships between species because of the basic hereditary systems that DNA and RNA use. These systems are used to pass on genes from parents to their offspring. Because of this, it tells how species are closely or distantly related. Telling if species are closely or distantly related, is very similar to what Darwin’s branched out tree of life looks like, like it was shown in the video. This tree shows how all species are related together, whether they are closely related or distantly, all because of their DNA. That is how DNA proved Darwin’s theory of evolution.

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