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

Arab League Delays Forming Joint Force

Delay grows out of one of original obstacles facing pan-Arab force, analysts say: 'They may agree on the principle, but they continue to argue about how to implement the project' More

Pakistan Demands Afghanistan Protect Its Kabul Mission, Staff

Officials in Islamabad say Afghan agents are harassing Pakistani embassy personnel, particularly those living outside of mission’s compound More

US Survey: Trump Lead Grows in Republican Presidential Contest

Quinnipiac University poll shows brash billionaire real estate mogul with 28 percent support among Republican voters 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.
Colombians Flee Venezuela as Border Crisis Escalatesi
X
August 27, 2015 2:08 AM
Hundreds of Colombians have fled Venezuela since last week, amid an escalating border crisis between the two countries. Last week, Venezuelan President Nicolas Maduro ordered the closure of a key border crossing after smugglers injured three Venezuelan soldiers and a civilian. The president also ordered the deportation of Colombians who are in Venezuela illegally. Zlatica Hoke reports.
Video

Video Colombians Flee Venezuela as Border Crisis Escalates

Hundreds of Colombians have fled Venezuela since last week, amid an escalating border crisis between the two countries. Last week, Venezuelan President Nicolas Maduro ordered the closure of a key border crossing after smugglers injured three Venezuelan soldiers and a civilian. The president also ordered the deportation of Colombians who are in Venezuela illegally. Zlatica Hoke reports.
Video

Video Is China's Economic Data Accurate?

Some investors say China's wild stock market gyrations have been made worse by worries about the reliability of that nation's economic data. And some critics say the reports can mislead investors by painting an unrealistically-strong picture of the economy. A key China scholar says Beijing is not fudging ((manipulating)) the numbers, but that the economy is evolving quickly from smoke-stack industries to services, and the ways of tracking new economic activity are falling behind the change. V
Video

Video Next to Iran, Climate at Forefront of Obama Agenda

President Barack Obama this week announced new initiatives aimed at making it easier for Americans to access renewable energy sources such as solar and wind. Obama is not slowing down when it comes to pushing through climate change measures, an issue he says is the greatest threat to the country’s national security. VOA correspondent Aru Pande has more from the White House.
Video

Video Shipping Containers Provide Experimental Housing

Housing prices around the San Francisco Bay area are out of reach for many people, so some young entrepreneurs, artists and tech industry workers are creating their own houses using converted shipping containers. But as VOA's Mike O’Sullivan reports from Oakland, the effort requires ingenuity and dealing with restrictive local laws.
Video

Video Arctic Draws International Competition for Oil

A new geopolitical “Great Game” is underway in earth’s northernmost region, the Arctic, where Russia has claimed a large area for resource development and President Barack Obama recently approved Shell Oil Company’s test-drilling project in an area under U.S. control. Greg Flakus reports.
Video

Video Philippine Maritime Police: Chinese Fishermen a Threat to Country’s Security

China and the Philippines both claim maritime rights in the South China Sea.  That includes the right to fish in those waters. Jason Strother reports on how the Philippines is catching Chinese nationals it says are illegal poachers. He has the story from Palawan province.
Video

Video Technique May Eliminate Drill-and-Fill Dental Care

Many people dread visiting dentists because they're afraid of drills. Now, however, a technology developed by a British firm promises to eliminate the need for mechanical cleaning of dental cavities by speeding a natural process of tooth repair. VOA’s George Putic reports.
Video

Video China's Spratly Island Building Said to Light Up the Night 'Like A City'

Southeast Asian countries claim China has illegally seized territory in the Spratly islands. It is especially a concern for a Philippine mayor who says Beijing is occupying parts of his municipality. Jason Strother reports from the capital of Palawan province, Puerto Princesa.
Video

Video Ages-old Ice Reveals Secrets of Climate Change

Ice caps don't just exist at the world's poles. There are also tropical ice caps, and the largest sits atop the Peruvian Andes - but it is melting, quickly, and may be gone within the next 20 years. George Putic reports scientists are now rushing to take samples to get at the valuable information about climate change locked in the ice.
Video

Video French Experiment in Integrating Roma Under Threat

Plans to destroy France’s oldest slum have sparked an outcry on the part of its Roma residents. As Lisa Bryant reports from the Paris suburb of La Courneuve, rights groups argue the community is a fledgling experiment on integrating Roma who are often outcasts in many parts of Europe.
Video

Video Kenyans Turn to Agriculture for Business

Each year Kenyan universities continue to churn out graduates for the job market despite the already existing high rate of unemployment among youth in the country. Some of these young men and women have realized that agriculture can be as rewarding as any other business or job, and they are resorting to agribusiness in large numbers as a way of tackling unemployment. Rael Ombuor reports for VOA.
Video

Video First Women Graduate Elite Army Ranger School

Two women are making history for the U.S. Army by proving they are among the toughest of the tough. VOA's Carla Babb reports from Fort Benning, Georgia as 94 men and those two women rise as graduates of the difficult Ranger school.

VOA Blogs