Will bacteria die out? The world is filled with very diverse populations of microbes, and it is widely accepted that because of the sheer number of bacterial populations bacteria rarely die out or die off.
However, a new study shows that this is not the case and that bacteria, like many other species, have died out. However, it has been difficult to track these declines in populations as bacteria have avoided the large planet-wide mass extinctions that are easily detected in the fossil record.
"Bacteria rarely fossilize, so we know very little about how the microbial landscape has evolved over time," said Stilianos Louca, head of the study. "Sequencing and math helped us fill the bacterial pedigree, map it over time, and expose it to extinction."
Researchers from University of British Columbia Caltech 1
"This study would not have been possible 10 years ago," said Michael Doebeli, lead author of the article. "Today's availability of extensive sequencing data and powerful computational resources allowed us to perform the complex mathematical analysis."
Although researchers were able to trace the evolutionary history of an estimated 1.4 to 1.9 million bacterial lines over the years, pedigree represents only a small fraction of the total bacteria.
"While modern bacterial diversity is undoubtedly high, this is only a small portion of the diversity that evolution has produced in Earth's history," said Louca.
The results published in the journal Nature Ecology and Evolution show that bacteria have experienced thousands of extinctions over the years, between 45,000 and 95,000 in the last million years, to be exact.
Bacteria have managed to avoid large mass extinctions, and the researchers found that they were able to exponentially diversify thousands of extinctions within their tree without interruption.
Researchers now plan to study the evolution of bacteria and their physiological properties over the years, to see what advantages bacteria have for developing and maintaining such high numbers and diversity.
by Kay Vandette Earth.com Author Writer
Credit: Stilianos Louca, University of British Columbia