Fossil Evidence Essay Example for Free

Fossil Evidence Essay 1. A. Fossil evidence has been used to support evolution. Paleontologists have dug up old bones and other things that were preserved in sedimentary rock. All of these things that were found show evidence that there was life long ago, however that’s not the only thing these fossils show. Fossils also show that there have been changes in the organisms that have inhabited this earth. The reason it supports that is once we compare the fossils to another organism, by using many different techniques, we can then see how the fossil from back then has adapted and evolved into this new organism. However it is still the same organism just modified to the environment it lives in during that time period. Just like everything else that has positives, this also has some negatives. One of the weaknesses of fossil evidence is that many organisms that died never got preserved because of where they were located. Not only were some organisms not fossilized, but some fossils were destroyed by geological processes. That leaves only some to be found. Despite these weaknesses the fossil record is still a great tool to show us the biological change that has occurred over vast amounts of time. B. The relationship between many organisms can be traced back to a common ancestor. As time progresses organisms evolve and change from this common ancestor, making it harder to just see the relationships between organisms. There are three types of evidence that explains how organisms can be related and that it just is the organism evolving; comparative anatomy, comparative biochemistry, and comparative embryology. One of the ones I am discussing is comparative biochemistry which is when you compare organisms by the similarity of their DNA, proteins, genes, gene products and their common genetic code. DNA, RNA, the genetic code and proteins are similar in all organisms. When the genetic and molecular similarity between species is great, that means that those two species are closer to sharing a common ancestor. The second one I will explain is comparative anatomy. This also shows that organisms share a common ancestor, but proves it by the similarities of the organism’s anatomical structure. You look at the organism’s body parts and their anatomy and look to see if there is any connection between the organisms. There are two major concepts to comparative anatomy; homologous structures and analogous structures. Homologous is when the structures are  similar due to common descent. While analogous is when structures are similar because they evolved in similar environments. You do this by taking the bone structures and looking the appendages, because that is where you can see if one or multiple organisms have the same bone structure for that particular area.