Microbe in evolutionary stasis for ‘175 million years’!
A research team examining the genome of the bacterium. Candidatus Desulforudis audaxviator (CDA) have claimed that it has remained virtually unchanged for more than 175 million years. This is from when the alleged supercontinent Pangea started to break up, isolating populations of the bacteria from each other. “They appear to be living fossils from those days” stated paper co-author Ramunas Stepanauskas.
150 of the microbes were collected from three different continents for examination. The team had believed that bacteria normally adapt to different environments very quickly. As such they expected to find clear differences in the genetics of the populations and were shocked when this was not the case. The team ruled out cross contamination, and as the microbes live deep underground the team also ruled out that they could have travelled long distances. This left them with two options, 1 – recent dispersal, or 2 – ancient dispersal and evolutionary stasis.
The team favoured option two. However, in doing so had to admit, “This discovery shows that we must be careful when making assumptions about the speed of evolution and how we interpret the tree of life.” Lead author Eric Becraft said, “It is possible that some organisms go into an evolutionary full-sprint, while others slow to a crawl, challenging the establishment of reliable molecular timelines.”
But this really is just a bad case of trying to have your cake and eat it, wanting evolution to always work through consistent information-adding mutations, except when it doesn’t. Option number one, a recent dispersal, makes much more sense with the bacteria ending up in their current locations due to the action of Noah’s Flood, some 4,500 years ago.
- Becraft, E.D. and 15 others, Evolutionary stasis of a deep subsurface microbial lineage, ISME J, 6 Apr 2021.
- Fuge, L. Living fossil discovered below Earth’s surface; cosmosmagazine.com, 12 Apr 2021.