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

Photogallery Pistorius Sentenced, Taken to Prison

Pistorius, convicted of culpable homicide in shooting death of girlfriend Reeva Steenkamp, will likely serve about 10 months of five-year sentence, before completing it under house arrest More

UN to Aid Central Africa in Polio Vaccinations

Synchronized vaccinations will be conducted after Cameroon reports a fifth case of the wild polio virus in its territory More

WHO: Ebola Vaccine May Be in Use by Jan.

WHO assistant director Dr. Marie Paule Kieny says clinical trials of Ebola vaccines are underway or planned in Europe, US and Africa 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.
After Decades of Pressure, Luxembourg Drops Bank Secrecy Rulesi
X
October 21, 2014 12:20 AM
European Union finance ministers have reached a breakthrough agreement that will make it more difficult for tax cheats to hide their money. The new legislation, which had been blocked for years by countries with a reputation as tax havens, was approved last week after Luxembourg and Austria agreed to lift their vetoes. But as Mil Arcega reports, it doesn’t mean tax cheats have run out of places to keep their money hidden.
Video

Video After Decades of Pressure, Luxembourg Drops Bank Secrecy Rules

European Union finance ministers have reached a breakthrough agreement that will make it more difficult for tax cheats to hide their money. The new legislation, which had been blocked for years by countries with a reputation as tax havens, was approved last week after Luxembourg and Austria agreed to lift their vetoes. But as Mil Arcega reports, it doesn’t mean tax cheats have run out of places to keep their money hidden.
Video

Video Kobani Refugees Welcome, Turkey Criticizes, US Airdrop

Residents of Kobani in northern Syria have welcomed the airdrop of weapons, ammunition and medicine to Kurdish militia who are resisting the seizure of their city by Islamic State militants. The Turkish government, however, has criticized the operation. VOA’s Scott Bobb reports from southeastern Turkey, across the border from Kobani.
Video

Video China Political Meeting Seeks to Improve Rule of Law

China’s communist leaders will host a top level political meeting this week, called the Fourth Plenum, and for the first time in the party’s history, rule of law will be a key item on the agenda. Analysts and Chinese media reports say the meetings could see the approval of long-awaited measures aimed at giving courts more independence and include steps to enhance an already aggressive and high-reaching anti-corruption drive. VOA’s Bill Ide has more from Beijing.
Video

Video US ‘Death Cafes’ Put Focus on the Finale

In contemporary America, death usually is a topic to be avoided. But the growing “death café” movement encourages people to discuss their fears and desires about their final moments. VOA’s Jerome Socolovsky reports.
Video

Video Ebola Orphanage Opens in Sierra Leone

Sierra Leone's first Ebola orphanage has opened in the Kailahun district. Hundreds of children orphaned since the beginning of the Ebola outbreak face stigma and rejection with nobody to care for them. Adam Bailes reports for VOA about a new interim care center that's aimed at helping the growing number of children affected by Ebola.
Video

Video Young Nairobi Tech Innovator on 'Track' in Security Business

A 24-year-old technology innovator in Nairobi has invented a tracking device that monitors and secures cars. He has also come up with what he claims is the most robust audio-visual surveillance system yet. As Lenny Ruvaga reports from the Kenyan capital, his innovations are offering alternative security solutions.
Video

Video Latinas Converting to Islam for Identity, Structure

Latinos are one of the fastest growing groups in the Muslim religion. According to the Pew Research Center, about 6 percent of American Muslims are Latino. And a little more than half of new converts are female. VOA’s Carolyn Presutti travelled to Miami, Florida -- where two out of every three residents is Hispanic -- to learn more.
Video

Video Exclusive: American Joins Kurds' Anti-IS Fight

The United States and other Western nations have expressed alarm about their citizens joining Islamic State forces in Syria and Iraq. In a rare counterpoint to the phenomenon, an American has taken up arms with the militants' Syrian Kurdish opponents. Elizabeth Arrott has more in this exclusive profile by VOA Kurdish reporter Zana Omer in Ras al Ayn, Syria.
Video

Video South Korea Confronts Violence Within Military Ranks

Every able-bodied South Korean male between 18 and 35 must serve for 21 to 36 months in the country’s armed forces, depending upon the specific branch. For many, service is a rite of passage to manhood. But there are growing concerns that bullying and violence come along with the tradition. Reporter Jason Strother has more from Seoul.
Video

Video North Carolina Emerges as Key Election Battleground

U.S. congressional midterm elections will be held on November 4th and most political analysts give Republicans an excellent chance to win a majority in the U.S. Senate, which Democrats now control. So what are the issues driving voters in this congressional election year? VOA National Correspondent Jim Malone traveled to North Carolina, one of the most politically competitive states in the country, to find out.
Video

Video Comanche People Maintain Pride in Their Heritage

The Comanche (Indian nation) once were called the “Lords of the Plains,” with an empire that included half the land area of current day Texas, large parts of Oklahoma, New Mexico, Kansas and Colorado.The fierceness and battle prowess of these warriors on horseback delayed the settlement of most of West Texas for four decades. VOA’s Greg Flakus reports from Lawton, Oklahoma, that while their warrior days are over, the 15,000 members of the Comanche Nation remain a proud people.
Video

Video Turkey Campus Attacks Raise Islamic Radicalization Fears

Concerns are growing in Turkey of Islamic radicalization at some universities, after clashes between supporters of the jihadist group Islamic State (IS) or ISIS, and those opposed to the extremists. Pro-jihadist literature is on sale openly on the streets of Istanbul. Critics accuse the government of turning a blind eye to radicalism at home, while Kurds accuse the president of supporting IS - a charge strongly denied. Henry Ridgwell reports from London.

All About America

AppleAndroid