Entry #2: Major Transitions in Evolution

Mayhew proposed that sex was a major transition and so he goes into the whole process of meiosis and the way it works. He also talks about autotrophic and heterotrophic origins of the biosphere. Dawkins proposed and talks about DNA and replicators that competed for these 'building blocks'. He then proposes that the replicators that survived are the ones that made 'survival machines' to live in. These survival machines are what multicellular organisms are. Both Dawkins and Mayhew talk about DNA and they both talk about the way an organism is made up when two organisms have sex and the process that takes place internally on a molecular level. The differences between these two is that Mayhew talks about recombination and the different processes that may have favored it and he also talks about mutations that can occur which affects the genes of an organism. The scenario that is most likely when choosing between the heterotrophic and autotrophic theories on the origin of life is the autotrophic theory. The autotrophic theory makes more sense on a scientific level and seems like there was more thought put into how replicators became multicellular organisms. The fact that the autotrophic theory has many reasons for why it had taken place also makes it a better and more believable theory rather than the heterotrophic theory. It can be very so that a prokaryotic cell had lost its cell wall in order to engulf large organic particles.