Oxygen & Life Evolution

Oxygen played a key role in the evolution of complex organisms, according to new research published in BMC Evolutionary Biology. The study shows that the complexity of life forms increased earlier than was thought, and in parallel with the availability of oxygen as an energy source. In the largest study to date that does not focus on vertebrates, researchers from Pennsylvania State University used molecular dating methods to create a new timeline of eukaryotic evolution. By adding information about the numbers of different cell types possessed by each group of organisms, the researchers reconstructed how the complexity of life has increased over time. The study shows that organisms containing more varied cell types evolved following increases in atmospheric oxygen. Professor Blair Hedges, who led the research team said: "To build a complex multicellular organism, with all the communication and signalling between cells it entails, you need energy. With no oxygen or mitochondria, complex organisms couldn't get enough of this energy to develop." The study showed that organisms containing more than two or three different cell types appeared soon after the surface environment became oxygenated around 2,300 million years ago. This was around the same time that cells became able to extract the energy from oxygen, thanks to the emergence of mitochondria.

Category:

Science & Technology

Tags:

• Oxygen
• The Evolution of Life

[worldswonders]

What you refer to is known as abiogenesis, i.e. the spontaneous appearance of life from inanimate matters. In fact, the view that the spontaneous appearance of the first form of life on earth in an oxygen-less atmosphere has been the basis for most abiogenesis theories. However, the first primitive simple life might have been appeared without oxygen but all the more complex living organisms evolved from this might require oxygen to survive and reproduce.

[kogolz]

In my mind I always thoughted that oxygen played the part of a catalyst in a chemical reaction that created life. Given the fact that even today we have multicellurar organisms that live with no oxygen whatsoeven throughout their existance makes me think that life in other forms can be created in environments with no oxygen with another chemical, not oxygen, playing the role of the catalyst.