1+What+is+the+origin+of+life?+Mark+and+Tasha

What is the origin of life?

Chemical Evolution:  Arthur Stanley Eddington first suggested in 1920. It is also known as nucleosynthesis. (a) One theory of the origin of life is chemical evolution. This is the idea that all life evolved from space--or meteoroids hitting Earth rather. These rocks hitting down on our planet caused new molecules to be brought about. And these molecules then cause the creation of RNA and later DNA. The Big Bang Theory further explains this process. This theory is one that scientists feel is most sensible although there are multiple other theories. (b) The first living things on Earth were prokaryotes with a type of cell similar to present-day bacteria. Prokaryote fossils have been found in 3.4-million-year-old rock in the southern part of Africa and in even older rocks in Australia, including some that appear to be photosynthetic. All forms of life are theorized to have evolved from the original prokaryotes, probably 3.5-4.0 billion years ago. So in sum, fossils from earlier life give us proof to this theory of chemical evolution.

(c) Another explanation of these fossils is "Community Clay." This theory was originated by Alexander Graham Cairns-Smith and states that the first molecules of life began on clay. These surfaces might not only have concentrated these organic compounds together, but also helped organize them into patterns much like our genes do now. Such organisms that were formed by this method were likely to stick around the clay that they were "born" on. Later on, dying off and leaving their imprints on the clay and giving us the fossils that we examine today. (d) In light of the evidence, the model should not change. Although there are many theories as to where fossils come from, we can really make sense of the theory of chemical evolution and see that living things that are unlike what organisms we know today existed in a period of time before us. Perhaps in the chemical evolution idea there should be a part where the organisms die off and imprint themselves in the clay to further this evidence, but I'm positive we all understand that living organisms die off and their remains eventually decay and possible are covered and perserved. Chemical Evolution is not in fact the only theory of life that could have created the fossils we see today, however it is the one that makes the most sense in our eyes.

Evidence: