• Email Us: [email protected]
  • Contact Us: +1 718 618 4351
  • Skip to main content
  • Skip to primary sidebar

Medical Market Report

  • Home
  • All Reports
  • About Us
  • Contact Us

Could Earth’s Biggest Extinction Event Have Been Caused By A Single Gene Transfer?

December 9, 2022 by Deborah Bloomfield

Think of an extinction event and your mind probably leaps to the asteroid that killed the dinosaurs – but Earth has been through five mass extinction events (so far) and is possibly going through our sixth.

Of the extinction events, the Cretaceous mass extinction event that put an end to the non-avian dinosaurs is not even the largest. That honor goes to the Permian mass extinction, aka The Great Dying, that wiped out around 90 percent of all land species and 70 percent of all marine species on Earth. 

Advertisement

As well as this, a strange 10-million-year gap in coal created around the time of the extinction – known as the “coal gap” – suggests that vast numbers of coal-forming trees went extinct during the event, taking millions of years to recover.

Finding a time period in the fossil record where there is a sudden drop-off in species numbers is, apparently, the easy part. Scientists have proposed a number of explanations for the extinction and the causes behind them – from a catastrophic release of methane from the ocean floor to our old friend the asteroid impact. 

From studying rocks that formed at the time of the extinction, we know that oceans and shallow waters lacked oxygen in the late Permian period. Lack of oxygen (aka anoxia) looks like it certainly played a part in the extinction event, as well as having a domino effect. 

Advertisement

Sulfate-reducing microorganisms, which can perform anaerobic respiration using sulfate rather than old reliable O2, likely thrived in these low-oxygen environments. The hydrogen sulfide byproduct they produce, as well as turning oceans sulfidic as a side order to their lack of oxygen, could have been released into the atmosphere. Here, it may have poisoned plants and damaged the ozone layer, exposing life to killer levels of UV rays about 250 million years before it had developed sunscreen, plus heating up the planet in the process. Heating the oceans, in turn, could have caused frozen methane in the oceans to be released into the atmosphere, compounding the problem.

One alternative explanation for the extinction, proposed by a team from MIT in 2014, is perhaps the most worrying. Could the biggest extinction event the world has seen be caused by microbes?

Daniel Rothman, Professor of Geophysics at MIT, and his team noticed the rise of a certain microbe around the time of the extinction. Methanosarcina, a single-celled organism, became capable of digesting organic matter, producing methane as a byproduct, thanks to a single gene transfer from the bacteria Clostridia. 

Advertisement

The hypothesis is that Methanosarcina thrived at this time, spewing methane into the atmosphere and disrupting the carbon cycle, causing (or adding to) the disruption of the carbon cycle and ultimately fueling the extinction event. 

The chemical process involved in the microbes creating methane involves the metal nickel – meaning that if the team couldn’t find a corresponding higher amount of nickel during the extinction event, the hypothesis could effectively be discounted. However, the team looked at the most-studied sediments in South China, and found high levels of nickel, possibly backing up the theory.

“A single horizontal gene transfer instigated biogeochemical change, massive volcanism acted as a catalyst, and the resulting expansion of acetoclastic Methanosarcina acted to perturb CO2 and O2 levels,” the team concluded in the study.

Advertisement

“The ensuing biogeochemical disruption would likely have been widespread. For example, anaerobic methane oxidation may have increased sulfide levels, possibly resulting in a toxic release of hydrogen sulfide to the atmosphere, causing extinctions on land.”

The team stressed that, though more evidence is needed for the theory, the study could show how sensitive the Earth is to evolution in microbial life.

“The implications for today are that there [are] many ways in which natural fluctuations can happen in Earth’s carbon cycle,” Rothman told The Conversation. “When studying the changes happening to the carbon cycle now, we should try to take into consideration as many of those as possible to make future predictions.”

Advertisement

The study is still far from conclusive, with other explanations – or perhaps a combination of events – still very much in the running. It is also not possible to pin down precisely when Methanosarcina evolved to begin producing methane as a byproduct.  However, if this hypothesis is correct, it’s possible that up to 90 percent of the planet’s species were knocked out in part by a single gene transfer in a single microbe. 

Given the sheer volume of microbes on Earth, that isn’t the most reassuring possibility we’ve ever heard.

Deborah Bloomfield
Deborah Bloomfield

Related posts:

  1. Wildfire raging in Spain forces more than 900 to flee, a firefighter dies
  2. Amagi tunes into $100M for cloud-based video content creation, monetization
  3. Australia should do more to contain housing bubble, climate change-IMF
  4. Compromise needed to clinch global tax deal – France

Source Link: Could Earth's Biggest Extinction Event Have Been Caused By A Single Gene Transfer?

Filed Under: News

Primary Sidebar

  • If Insects Joined Forces They’d Weigh More Than All Humans And Livestock
  • Wormholes Distorting Light Could Be Our Most Powerful Eyes In The Sky
  • This Small, Vibrating Bracelet Might Change Your Life
  • Cavern Of Crab Shells Shows Neanderthals Were Fine Diners, Just Like Us
  • Scientists Ignored Animal Clitorises For Centuries – Now We’re Discovering Just How Varied They Are
  • How Closely Dogs Are Related To Wolves Can Influence If They Howl Or Bark
  • Woodpecker Fills Walls Of Home With 318 Kilograms Of Acorns
  • “Dead” Woman Discovered Alive And Gasping For Air In Body Bag
  • If You Want To Know Sea Level’s Future, Ask An Octopus
  • Man Develops Strong Irish Accent As Incredibly Rare Complication Of Prostate Cancer
  • How Scientists Work Out What Ancient Hominins Ate
  • Cleaner Fish Easily Recognize Their Own Faces, New Research Finds
  • Cave Sealed For Thousands Of Years Reveals Claw Marks Of Prehistoric Bears
  • What Is The Information Catastrophe, And When Is It Going To Happen?
  • Powerful “Atmospheric River” Storms Are Slowing Arctic Sea Ice Recovery
  • “New Layer” Of Earth Oozes Gently Like Rocky Honey Under The Crust
  • Even The Earth’s Magnetic Field Has Moon-Driven Tides
  • Nine-Year-Old Boy Becomes One Of The Youngest High School Graduates Ever
  • New Earth-Sized Planet May Be Habitable, Although Half Is In Eternal Darkness
  • DNA Of Skull In Alaska Solves Mystery Of New Yorker Missing Since 1976
  • Business
  • Health
  • News
  • Science
  • Technology
  • +1 718 618 4351
  • +91 78878 22626
  • [email protected]
Office Address
Prudour Pvt. Ltd. 420 Lexington Avenue Suite 300 New York City, NY 10170.

Powered by Prudour Network

Copyrights © 2023 · Medical Market Report. All Rights Reserved.

Go to mobile version