Bacteria do become extinct at substantial rates, finds a new study, contradicting widely held scientific thinking that the microbes rarely die because of their very large population.
For the study, published in Nature Ecology and Evolution, the team used massive DNA sequencing and big data analysis to create the first evolutionary tree encompassing a large fraction of Earth’s bacteria over the past billion years.
Despite the frequent, steady extinction of individual species, the study shows that overall bacteria have been diversifying exponentially without interruption.
The team estimated 1.4-1.9 million bacterial lineages exist on Earth today. However, 45,000 to 95,000 extinctions occurred in the last million years.
The researchers suspected that competition between bacterial species drives the high rate of microbial extinctions, leaving them less prone to sudden mass, multi-species extinctions.