Quantity of genetic information exchange on earth
The main driver of evolution is communication, both direct and indirect, between genomes. Genetic information exchanged via sexual reproduction is arguably the largest source of genetic variation. Consider the volume of DNA exchange between organisms. The earth has roughly 5 × 10^30 microbes living on it at any given moment, of which, say, one in a hundred million is undergoing some sort of transfer of genetic information with other microbes. The replication cycle of microbes ranges from about 20 min to days or months, so let us say the average replication cycle is 5 days. That means that there are something like 10^18 genetic signals exchanged per second around the
planet. Those signals are not on-off bits like the signals processed by computers; they are chunks of DNA often containing thousands of nucleotides organized into genes and control sequences. So, the genetic signal-processing activity of the earth’s biome is on the order of 10^23 bits per second. A human brain processes about a thousand trillion – 10^15 – bits per second.
All that signal exchange does nothing useful unless it is organized. Is nature’s processing power organized? You bet! All of the hundred million supercomputers’ worth of genetic information exchange going on in nature is, one way or another, involved in creating new genetic combinations resulting in new phenotypes. All of it is aimed at adaptation – generating alternative phenotypes in order to be apt to adapt to the environment.
The main driver of evolution is communication, both direct and indirect, between genomes. Genetic information exchanged via sexual reproduction is arguably the largest source of genetic variation. Consider the volume of DNA exchange between organisms. The earth has roughly 5 × 10^30 microbes living on it at any given moment, of which, say, one in a hundred million is undergoing some sort of transfer of genetic information with other microbes. The replication cycle of microbes ranges from about 20 min to days or months, so let us say the average replication cycle is 5 days. That means that there are something like 10^18 genetic signals exchanged per second around the
planet. Those signals are not on-off bits like the signals processed by computers; they are chunks of DNA often containing thousands of nucleotides organized into genes and control sequences. So, the genetic signal-processing activity of the earth’s biome is on the order of 10^23 bits per second. A human brain processes about a thousand trillion – 10^15 – bits per second.
All that signal exchange does nothing useful unless it is organized. Is nature’s processing power organized? You bet! All of the hundred million supercomputers’ worth of genetic information exchange going on in nature is, one way or another, involved in creating new genetic combinations resulting in new phenotypes. All of it is aimed at adaptation – generating alternative phenotypes in order to be apt to adapt to the environment.
