Ancient bacteria breathed long before oxygen became in abundance

Oxygen compensates today 21% of our atmosphereBut it wasn’t always so abundant. About 2.7 billion years ago, cyanobacteria – equal bacteria that generate energy through photosynthesis – develop and began to release oxygen into the oceans. This oxygen gradually accumulates in the atmosphere in a process called A great oxidized event (Goe), which took place between 2.4 and 2.1 billion years. However, new studies suggest that aerobic (oxygen) bacteria may have appeared long before Go.

An international team of researchers has reconstructed the evolutionary tree of one of the most living forms of life on Earth, revealing that bacteria may have adapted to the presence of oxygen long before it was abundant in our atmosphere. Their work detailed in a exploration Posted today in Science magazine, it triggered the previous assumption that most life before Goe was an anaerobic, that is, organisms that do not need oxygen to survive.

Researchers used a multidisciplinary approach to reconstruct evolutionary tree for bacteria and tracking when adapted to oxygen. This includes analyzing geological records, fossil evidence and over 1000 different bacterial genomes; implementation Phylogenetic reconciliation (Comparing the story of two closely intertwined life forms); and computer modeling. According to their evolutionary tree, the last common ancestor of modern bacteria probably existed somewhere between 4.4 and 3.9 billion years.

“This Combined Approach of Using Genomic Data, Fossils, and Earth’s Geochemical History Brings New Clarity to Evolutionary Timelines, Especially for Microbial Groups That Don Don’s Have Szöllősi, a co-author on the study and an evolutionary biologist from the okinawa institute of science and technology graduate university, Said in a university statementS

Their results suggest that some aerobic bacteria appeared before Goe, about 3.22 to 3.25 billion years ago. Probably these bacterial genera was the ancestors of cyanobacteria, which means that they developed the ability to metabolize small amounts of oxygen before photosynthesis develop. In fact, the study suggests that the adaptation of oxygen may have played a decisive role in the evolution of photosynthetic abilities of cyanobacteria – and as a result, changes in the atmosphere of the Earth during Goe.

The approach of the team “works well to study the spread of aerobic metabolism and can also be a useful approach to exploring how other traits appear and interact with the displacing environment on the planet during geological times,” says Tom Williams, a calculated evolutionary biologist at the University of Bristol, as well as the test.

The study is also a reminder of the fact that the atmosphere we enjoy today has been formed by billions of years of microbial activity.