News / Science & Technology

Invasive Species Could Trigger Next Massive Extinction

Clues to a modern apocalypse found in ancient fossils

According to an expert, the rate of species loss today is higher than anything documented in the fossil record and many creatures could soon go the way of the dinosaurs.
According to an expert, the rate of species loss today is higher than anything documented in the fossil record and many creatures could soon go the way of the dinosaurs.

Multimedia

Audio
Rosanne Skirble

The most recent mass extinction was 65 million years ago when the dinosaurs disappeared. That was one of five mass extinctions in earth's history - when the number of species dramatically declines. Scientists are eyeing the next mass extinction, which might be triggered by an invasive species.

According to Ohio University paleo-geologist Alycia Stigall, the sixth era of mass extinction is already under way. It began about a million years ago when big animals like wholly mammoths and saber tooth cats went extinct.

The Ocean in Devonian times: Is the past a prologue in biodiversity collapse?
The Ocean in Devonian times: Is the past a prologue in biodiversity collapse?

Collapse

Stigall sees clues to a modern apocalypse in the fossil record from the Devonian period 360 million years ago.

The Devonian was an era of mass extinction, when marine ecosystems completely collapsed, and reefs disappeared from the world's oceans. Sea levels rose and fell. Continents moved closer together. The stage was set for safe passage of invasive species. The invaders captured resources and adapted to their new living conditions, overwhelming native species.  

Stigall says it was a huge change in how the ecosystem was structured. "What you realize is that the main organisms that are dominant in the rocks suddenly change. So the major groups of organisms, the major types of corals, the major type of shell fish, that we see beneath the 'biodiversity crisis interval' are completely different from the major groups of organisms that we see afterwards."

Alycia Stigall, in her laboratory, displays fossils and tools of her research.
Alycia Stigall, in her laboratory, displays fossils and tools of her research.

Bio-diversitycrisis

Species go extinct at regular intervals in earth's history, but the mass extinction during the late-Devonian was unlike any other in the planet's history. The formation of new species came to a halt. Stigall calls it a "bio-diversity crisis."  "These new groups that are trying to become a new species, rather than to be able to expand their population and be successful, they get out competed for resources and just go extinct."  

Stigall sees parallels with our world, in which human activities - agriculture, industry, population growth and urbanization - are promoting invasives, accelerating habitat loss and pushing species toward extinction.

"Evolution of new species or speciation is harder to see because the process of speciation takes between 10,000 and 50,000 years. Whereas you could drive a species extinct in a decade."

These small shelled marine animals were some of the most common inhabitants of the late Devonian period.
These small shelled marine animals were some of the most common inhabitants of the late Devonian period.

Stigall adds that if invasive species could trigger a mass extinction 360 million years ago, similar forces could be at work today. "What we can see from this is that things that are very limited or specialized in their ecology are the types of species that are both more likely to go extinct and less likely to have successful speciation down the line. So we may want to focus resources on species that are a little more broadly adapted that are still in their natural local habitats."  

According to Stigall, the rate of species loss today is higher than anything documented in the fossil record. "We are looking at basically a whole series of potential effects that line up very well with the worst mass extinctions that occurred, which was 250 million years ago where 96 percent of the earth's species went extinct."  

Stigall says her study underscores the long-term impact of invasive species.  "The more we know about this process," she says, "the more we will understand how best to preserve bio-diversity."  The work is published in PloS ONE.

You May Like

Could Nemtsov Threaten Putin in Death as in Life?

Dynamic and debonair opposition leader had supported liberal economic reforms, criticized Russian president's aggression in Ukraine More

Oil Smuggling Highlights Challenges in Shutting Down IS Finances

Pentagon spokesman says Islamic State 'certainly continues to get revenue from the oil industry black market' but that airstrikes have made a dent More

India Focuses on Infrastructure, Investment to Propel Economy

Government expects economy to grow at 8 to 8.5 percent in next fiscal year 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.
US Supreme Court Hears Hijab Discrimination Casei
X
Katherine Gypson
February 25, 2015 11:30 PM
The U.S. Supreme Court has heard opening arguments in a workplace religious discrimination case that examines whether a clothing store can refuse to hire a young woman for wearing the headscarf she says is a symbol of her Muslim faith. Katherine Gypson reports from the Supreme Court.
Video

Video US Supreme Court Hears Hijab Discrimination Case

The U.S. Supreme Court has heard opening arguments in a workplace religious discrimination case that examines whether a clothing store can refuse to hire a young woman for wearing the headscarf she says is a symbol of her Muslim faith. Katherine Gypson reports from the Supreme Court.
Video

Video Falling Gas Prices Hurt Nascent Illinois Hydraulic Fracturing Industry

Falling oil prices are helping consumers purchase cheaper petroleum at the pump. But that’s made hydraulic fracturing or “fracking” less economically viable for the companies in the United States invested in the process. VOA’s Kane Farabaugh reports on one Midwestern town that was hoping to change its fortunes by cashing in on the next big U.S. oil boom.
Video

Video Fighting in Sudan's South Kordofan Fuels Mass Displacement

Heavy fighting in Sudan's South Kordofan state is causing hundreds of thousands to flee into uncertain conditions. Local aid organizations estimate as many as 400,000 civilians have been internally displaced since the conflict began more than three years ago, while another 250,000 have fled across the border to refugee camps in South Sudan. VOA's Adam Bailes reports.
Video

Video Lao Dam Project Runs Into Opposition

A Lao dam project on a section of the Mekong River is drawing opposition from local fishermen, international environmental groups and neighboring countries. VOA's Say Mony visited the region to investigate the concerns. Colin Lovett narrates.
Video

Video A Filmmaker Discovers Her Biracial Identity in "Little White Lie

Lacey Schwartz grew up in an upper middle-class Jewish family, in a town in upstate New York where almost everyone she knew was white. She assumed that she was, as well. Her recent documentary, Little White Lie, tells the story of how she uncovered the secret of her true racial background. VOA’s Carolyn Weaver has more on the film.
Video

Video Deep Under Antarctic Ice Sheet, Life!

With the end of summer in the Southern hemisphere, the Antarctic research season is over. Scientists from Northern Illinois University are back in their laboratory after a 3-month expedition on the Ross Ice Shelf, the world’s largest floating ice sheet. As VOA’s Rosanne Skirble reports, they hope to find clues to explain the dynamics of the rapidly melting ice and its impact on sea level rise.
Video

Video US-Cuba Normalization Talks Resume Friday

Negotiations aimed at normalizing diplomatic relations between the U.S. and Cuba resume Friday. On the table: lifting a half-century trade embargo and easing banking and travel restrictions. There's opposition in Congress, but some analysts say there may be sufficient political and economic incentives in both nations for a potential breakthrough this year. VOA's Mil Arcega reports.
Video

Video Pakistan's Deadline For SIM Registration Has Cellphone Users Scrambling

Pakistani cell phone users have until midnight Thursday to register their SIM cards, or their service will be cut off. While some privacy experts worry about government intrusion, many Pakistanis are just worried about keeping their phone lines open. VOA Deewa reporter Arshad Muhmand has more from Peshawar.
Video

Video Myanmar Warns Factory Workers to End Strikes

Outside Myanmar's main city Yangon, thousands of workers walked off their jobs earlier this month demanding a doubling of their wages, pay raises after a year and input from labor unions on industrial regulations. Since Friday, the standoff has grown more tense as police moved in to disrupt the sit-ins, resulting in clashes that injured people from both sides. VOA correspondent Steve Herman visited industrial zones which have become a focus of Myanmar's fledgling workers rights movement.
Video

Video Oscar Winners Do More Than Thank the Academy

The Academy Awards presentation is Hollywood’s night to reward the best movies from the previous year. It’s typically a lot of glitter, a lot of thank you’s, a lot of speeches. But many of this year’s speeches carried messages beyond the thank you's. VOA’s Carolyn Presutti takes a look.

All About America

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More