News / Science & Technology

Microbes Trigger Largest Mass Extinction Ever

FILE - Limestone layers in between volcanic ash beds from Meishan, China, during the
FILE - Limestone layers in between volcanic ash beds from Meishan, China, during the "Great Die-Off" (Courtesy: Shuzhong Shen).
Rosanne Skirble
MIT scientists say almost everything on Earth died 252 million years ago in the largest mass extinction on the planet.

While scientists have come up with a number of theories — from asteroids to volcanoes and raging coal fires — the research team from the Massachusetts Institute of Technology says the culprit was a methane-spewing microbe.

According to the team's lead researcher, Daniel Rothman, MIT Professor of Geophysics, massive volcanic eruptions and chemical changes coincided to dramatically change the climate and the chemistry of the ocean.

“When one examines old rocks that were deposited at the time, the results of those geochemical analyses indicate that there was a large influx of carbon into the Earth’s system — that is, the oceans and the atmosphere — and that carbon likely entered system as CO2," Rothman says, explaining that the change happened in the geological blink of an eye — about 60,000 years — killing 96 percent of life in the ocean and 70 percent of life on land in what's known as the Permian-Triassic extinction event — or, simply put, the Great Dying.

The carbon dioxide that erupted from volcanos was a potent greenhouse gas that, in large doses, warms the air and turns oceans acidic. But, Rothman says, the volcanic activity in what is today Siberia cannot solely account for the global geo-chemical change.

“It’s a gross correlation, and the question is how it might be related," he says. "It’s not the only question, but it is the one of the questions we address in our paper.”  

Methane-spewing marine microbes

One answer came from an analysis of the genomic record that revealed a marine microbe that produces methane and could be an important player in the massive die-off.

“Methane-producing microbes had already been present, but this was a particular microbe that could do it a little bit more efficiently than the others," he explains. "And so we’ve hypothesized that it might have been responsible for the outburst of carbon into the system — originally methane — and the methane would have been oxidized to CO2.”

Writing in the Proceedings of the National Academy of Sciences, Rothman and colleagues report that the methane microbes experienced an explosive growth spurt fueled by the mineral nickel, which they found in sedimentary rocks from those Siberian eruptions.

The nickel concentrations rose considerably just before extinction, which would have made a very favorable environment for the methane-producing microbes.

Massive extinction natural event

Unlike today's climate disruption, primarily caused by the carbon pollution of fossil fuel-based power plants, cars and buildings, the Permian-Triassic extinction was a natural event that heated up the Earth’s biological systems.

“It’s not that unusual in the history of life for such things to occur," Rothman says. "The point is that life and the environment interact. They always have and they always will, and we collectively need to be careful how we handle our end of the equation.”

You May Like

Lesotho Faces New Round of Violence, Political Crisis

Brutal killing of military officer has sent former leaders back into S. Africa where they're watching anxiously as regional officials head in to try to restore peace More

Video US Diplomat Expects Adoption of Bosnian Massacre Anniversary Resolution

Samantha Power says there's broad consensus about killings in Bosnia's war, but Russia calls resolution 'divisive,' backs UN countermeasure More

UN Report Exposes Widespread Boko Haram Atrocities

Damning report graphically details pattern of vicious, widespread atrocities committed by Islamist militants More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Olympics Construction Scars Sacred Korean Mountaini
X
July 02, 2015 4:10 AM
Environmentalists in South Korea are protesting a Winter Olympics construction project to build a ski slope through a 500-year-old protected forest. Brian Padden reports that although there is strong national support for hosting the 2018 Pyeongchang Winter Olympics, there are growing public concerns over the costs and possible ecological damage at the revered mountain.
Video

Video Olympics Construction Scars Sacred Korean Mountain

Environmentalists in South Korea are protesting a Winter Olympics construction project to build a ski slope through a 500-year-old protected forest. Brian Padden reports that although there is strong national support for hosting the 2018 Pyeongchang Winter Olympics, there are growing public concerns over the costs and possible ecological damage at the revered mountain.
Video

Video Xenophobia Victims in South Africa Flee Violence, Then Return

Many Malawians fled South Africa early this year after xenophobic attacks on African immigrants. But many quickly found life was no better at home and have returned to South Africa – often illegally and without jobs, and facing the tough task of having to start over. Lameck Masina and Anita Powell file from Johannesburg.
Video

Video Family of American Marine Calls for Release From Iranian Prison

As the crowd of journalists covering the Iran talks swells, so too do the opportunities for media coverage.  Hoping to catch the attention of high-level diplomats, the family of American-Iranian marine Amir Hekmati is in Vienna, pleading for his release from an Iranian prison after nearly 4 years.  VOA’s Heather Murdock reports from Vienna.
Video

Video UK Holds Terror Drill as MPs Mull Tunisia Response

After pledging a tough response to last Friday’s terror attack in Tunisia, which came just days before the 10th anniversary of the bomb attacks on London’s transport network, British security services are shifting their focus to overseas counter-terror operations. VOA's Henry Ridgwell has more.
Video

Video Obama on Cuba: This is What Change Looks Like

President Barack Obama says the United States will soon reopen its embassy in Cuba for the first time since 1961, ending a half-century of isolation. VOA White House correspondent Luis Ramirez reports.
Video

Video Hate Groups Spread Influence Via Internet

Hate groups of various kinds are using the Internet for propaganda and recruitment, and a Jewish human rights organization that monitors these groups, the Simon Wiesenthal Center, says their influence is growing. The messages are different, but the calls to hatred or violence are similar. VOA's Mike O’Sullivan reports.
Video

Video US Silica Sand Mining Surge Worries Illinois Residents, Businesses

Increased domestic U.S. oil and gas production, thanks to advances known as “fracking,” has created a boom for other industries supporting that extraction. Demand for silica sand, used in fracking, could triple over the next five years. In the Midwest state of Illinois, people living near the mines are worried about how increased silica sand mining will affect their businesses and their health. VOA’s Kane Farabaugh has more in this first of a series of reports.
Video

Video Blind Somali Journalist Defies Odds in Mogadishu

Despite improving security in the last few years, Somalia remains one of the most dangerous countries to be a journalist – even more so for someone who cannot see. Abdulaziz Billow has the story of journalist Abdifatah Hassan Kalgacal, who has been reporting from the Somali capital for the last decade despite being blind.
Video

Video Texas Defies Same-Sex Marriage Ruling

Texas state officials have criticized the US Supreme Court decision giving same-sex couples the right to marry nationwide. The attorney general of Texas says last week's decision did not overrule constitutional "rights of religious liberty," and therefore officials performing wedding services can refuse to perform them for same-sex couples if it is against their religious beliefs. Zlatica Hoke reports on the controversy.
Video

Video Rabbi Hits Road to Heal Jewish-Muslim Relations in France

France is on high alert after last week's terrorist attack near the city Lyon, just six months after deadly Paris shootings. The attack have added new tensions to relations between French Jews and Muslims. France’s Jewish and Muslim communities also share a common heritage, though, and as far as one French rabbi is concerned, they are destined to be friends. From the Paris suburb of La Courneuve, Lisa Bryant reports about Rabbi Michel Serfaty and his friendship bus.
Video

Video Saudi Leaks Expose ‘Checkbook Diplomacy’ In Battle With Iran

Saudi Arabia’s willingness to wield its oil money on the global diplomatic stage appears to have been laid bare, after the website WikiLeaks published tens of thousands of leaked cables from Riyadh’s Ministry of Foreign Affairs. VOA's Henry Ridgwell reports.
Video

Video In Kenya, Police Said to Shoot First, Ask Questions Later

An organization that documents torture and extrajudicial killings says Kenyan police were responsible for 1,252 shooting deaths in five cities, including Nairobi, between 2009 and 2014, representing 67 percent of all gun deaths in the areas reviewed. Gabe Joselow has more from Nairobi.

VOA Blogs