Bacteria go extinct quite often, study reports

BY JOSEPH SCALISE
Posted on JAN 14, 2019

A new evolutionary map shows how many bacteria species have gone extinct over time.

While bacteria tend to avoid mass extinctions, the microorganisms die off at substantial rates, according to new researchin Nature Ecology & Evolution.

The new study -- run by a team of international scientists -- contradicts the common belief that microbe taxa rarely die off and shows they are not as hardy as previously believed.
To reach the new findings, researchers used a combination of DNA sequencing and big data analysis to create an evolutionary tree of Earth's bacteria.

"Bacteria rarely fossilize, so we know very little about how the microbial landscape has evolved over time," explained lead author Stilianos Louca, a researcher with University of British Columbia's Biodiversity Research Center, according to Phys.org. "Sequencing and math helped us fill in the bacterial family tree, map how they've diversified over time, and uncover their extinctions."

The team estimates there are 1.4 to 1.9 million bacterial lineages on Earth today. Between 45,000 and 95,000 distinct species went extinct in the last million years.

Though bacteria are still extremely diverse, that diversity has shifted many times throughout Earth's long history.

Rather than succumbing to planet-wide mass extinctions, most bacteria disappear as a result of competition between species. That conflict drives many die-offs, but also creates more resilient strains.

Now that researchers know such information, they next want to analyze how bacteria physiological properties evolve over time. They also want to use new technology to see if their ecological diversity increases at the same rate as their taxonomic diversity.

"This study wouldn't have been possible 10 years ago," said study co-author Michael Doebeli, a researcher at the University of British Columbia, according toZME Science. "Today's availability of massive sequencing data and powerful computational resources allowed us to perform the complex mathematical analysis.

 

 

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