As life has evolved, its complexity has increased exponentially, just like Moore’s law which states that the number of transistors on an integrated circuit doubles approximately every two years. The regression suggests that if life takes 10 billion years to evolve to the level of complexity associated with homo sapiens, then we may be among the first, if not the first, intelligent civilization in the Milky Way, negating Drakes Equation.
Our Solar Nebula formed from the remnants of an earlier star, suggesting that life from this period might be preserved in the original gas, dust and ice clouds. Life on Earth may be a continuation of a process that began many billions of years before the formation of our Solar System.
In a 2015 study, geneticists, Alexei Sharov at the National Institute on Ageing in Baltimore and Richard Gordon at the Gulf Specimen Marine Laboratory in Florida, extrapolated this trend backwards and found that by the measure of Moore’s Law, life is older than the Earth itself.
The team takes Moore’s Law back to zero complexity and the origin of life, by measuring the complexity of life and the rate at which it has increased from prokaryotes to eukaryotes to more complex creatures such as worms, fish, amphibians and eventually mammals. The result is an exponential increase identical to that behind Moore’s Law with the doubling time, however, expanding to 376 million years rather than two years.
The application of Linear regression of genetic complexity on a log scale extrapolated back to just one base pair suggests the time of the origin of life 9.7 billion years ago. This cosmic time scale for the evolution of life has important consequences: life took ca. 5 billion years to reach the complexity of bacteria; the environments in which life originated and evolved to the prokaryote stage may have been quite different from those envisaged on Earth.
The graph above shows the complexity of organisms, as measured by the length of functional non-redundant DNA per genome counted by nucleotide base pairs (bp), increases linearly with time (Sharov, 2012). Time is counted backwards in billions of years before the present (time 0).
Additionally they suggest that the evolution of advanced organisms has accelerated via development of additional information-processing systems: epigenetic memory, primitive mind, multicellular brain, language, books, computers, and Internet. As a result the doubling time of complexity has reached about every 20 years.
Ref: arxiv.org/abs/1304.3381: Life Before Earth
The Daily Galaxy via MIT Technology Review and Arxiv.org
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