ORIGINS OF LIFE

"MIT Technology Review is running a story about an arXiv paper in which geneticists Alexei A. Sharov and Richard Gordon propose that life as we know it originated 9.7 billion years ago. The researchers estimated the genetic complexity of phyla in the paleontological record by counting the number of non-redundant functional nucleotides in typical genomes of modern day descendants of each phylum. When plotting genetic complexity against time, the researchers found that genetic complexity increases exponentially, just as with Moore's law, but with a doubling rate of about once every 376 million years. Extrapolating backwards, the researchers estimate that life began about 4 billion years after the universe formed and evolved the first bacteria just before the Earth was formed. One might image that the supernova debris that formed the early solar system could have included bacteria-bearing chunks of rock from doomed planets circling supernova progenitor stars. If true, this retro-prediction has some interesting consequences in partly resolving the Fermi Paradox. Another interesting consequence for those attempting to recreate life's origins in a lab: bacteria may have evolved under conditions very different from those on earth."