Imagine that we are trying to work out how to move to other planets and how to live for millions of years. Now consider that the entire genetic blueprint for a human would fit inside an organism the size of a bacteria. A human egg cell is about the diameter of a human hair, 100 microns, but a human sperm head is about 5 microns. That sperm cell head at 5 microns contains all the genetic code of a complete intelligent adult human. Also in the range of .2 to 5 microns: Bacteria.
My idea is that a very advanced alien race could have invented the first bacteria that arrived on earth as a way to transport themselves to another world. Bacteria, which can live in space, survive radiation and near zero temperatures and can survive dormant as spores for 25 million years, repair their DNA and reproduce, would be like alien super sperm. Under the right conditions, as does a 5 micron human sperm cell, they grow into some large intelligent life form, perhaps the Grey aliens in the movies, or something with a form best adapted to the current environment.
Bacteria share genetic information (they learn) so we may just be in the phase where they are learning the best traits of life on this planet before they germinate into a new creature that takes over the planet.
Next step: Consider the genetic code of the oldest bacteria we’ve found.
October, 1999; 250-million-year-old bacteria were found in ancient sea salt beneath Carlsbad, New Mexico. The microscopic organisms were revived in a laboratory after being in ‘suspended animation’, encased in a hard-shelled spore, for an estimated 250 million years. The species has not been identified, but is referred to as strain 2-9-3, or B. permians.
But is it?
There are several reasons to doubt the antiquity of B. permians. The first concerns the extraordinary similarity of its 16S rRNA gene sequence to that of Bacillus marismortui. Bacillus marismortui was described by Arahal et al. (1999) as a moderately halophilic species from the Dead Sea and was later renamed Salibacillus marismortui (Arahal et al. 2000 ). The B. permians sequence differs from that of S. marismortui by only one transition and one transversion out of the 1,555 aligned and unambiguously determined nucleotides. In comparison, the 16S rRNA gene from Staphylococcus succinus, which was claimed to be “25–35 million years old” (Lambert et al. 1998 ), differs from its homolog in its closest present-day relative (a urinary pathogen called Staphylococcus saprophyticus) by 19 substitutions out of 1,525 aligned nucleotides.
How far back does bacteria go? At least 3.5 billion years according to a New York Times article from March 2017, but we don’t have DNA.
Heated disputes are nothing new in the search for the earliest life on Earth. In 1993 J. William Schopf, a paleontologist at the University of California, Los Angeles, and his colleagues found what that they, too, argued were the world’s oldest fossils: chainlike blobs in 3.46 billion-year-old rocks made, they said, by bacteria. Other researchers later argued that the structures were just oddly shaped minerals.
But additional specimens from other sites came to light over the past two decades, and many of them have withstood scrutiny. There is now solid evidence of life dating back about 3.5 billion years.