News / Science & Technology

Wildflowers' Disappearance May Have Doomed Ice Age Giants

FILE- Wildflowers bloom on a hill overlooking a fjord filled with icebergs near the south Greenland town of Narsaq, July 27, 2009.
FILE- Wildflowers bloom on a hill overlooking a fjord filled with icebergs near the south Greenland town of Narsaq, July 27, 2009.
Flower power may have meant the difference between life and death for some of the extinct giants of the Ice Age, including the mighty wooly mammoth and wooly rhinoceros.
Scientists who studied DNA preserved in Arctic permafrost sediments and in the remains of such ancient animals have concluded that these Ice Age beasts relied heavily on the protein-rich wildflowers that once blanketed the region.
But dramatic Ice Age climate change caused a huge decline in these plants, leaving the Arctic covered instead in grasses and shrubs that lacked the same nutritional value and could not sustain the big herbivorous mammals, the scientists reported in the journal Nature last week.
The change in vegetation began roughly 25,000 years ago and ended about 10,000 years ago - a time when many of the big animals slipped into extinction, the researchers said.
Scientists for years have been trying to figure out what caused this mass extinction, when two-thirds of all the large-bodied mammals in the Northern Hemisphere died out.
“Now we have, from my perspective at least, a very credible explanation,” Eske Willerslev of the University of Copenhagen, an expert in ancient DNA who led an international team of researchers, said in a telephone interview.
The findings contradicted the notion that humans arriving in these regions during the Ice Age caused the mass extinction by hunting the big animals into oblivion - the so-called overkill or Blitzkrieg hypothesis.
“We think that the major driver [of the mass extinction] is not the humans,” Willerslev said, although he did not rule out that human hunters may have delivered the coup de grace to some species already diminished by the dwindling food supplies.
The Arctic region once teemed with herds of big animals, in some ways resembling an African savanna. Large plant eaters included wooly mammoths, wooly rhinos, horses, bison, reindeer and camels, with predators including hyenas, saber-toothed cats, lions and huge short-faced bears.
The scientists carried out a 50,000-year history of the vegetation across the Arctic in Siberia and North America.
They obtained 242 permafrost sediment samples from various Arctic sites and studied the feces and stomach contents from the mummified remains of Ice Age animals recovered in places like Siberia. They determined the age of the samples and analyzed the DNA.
While many scientists had thought the ecosystem had been grasslands and the big animals were grass eaters, this study showed it instead was dominated by a kind of plant known as forbs - essentially wildflowers.
“The whole Arctic ecosystem looked extremely different from today. You can imagine these enormous steppes with no trees, no shrubs, but dominated by these small flowering plants,” Willerslev said.
Christian Brochmann, a botanist at the Natural History Museum at the University of Oslo, said the permafrost contained “a vast, frozen DNA archive left as footprints from past ecosystems,” that could be deciphered by exploring animal and plant collections already stored in museums.

You May Like

Video Getting to Zero AIDS Infections

More than 35 million people around the world are infected with HIV, a disease that is both preventable and treatable

Children, Childhoods Lost in European Refugee Crisis

According to UNICEF, 190,000 children applied for political asylum in Europe in the first 9 months of this year - twice as many as last year

What Happened When I Landed in Antarctica

Refael Klein chronicles what it's like to visit one of the coldest, most desolate places on Earth

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
With HIV, Can We Get to Zero?i
Carol Pearson
November 29, 2015 1:23 PM
The theme of this year's World AIDS Day is "Getting to Zero." The U.N. says new HIV infections have been reduced by 35 percent since 2000 and AIDS-related deaths are down by 42 percent since the peak in 2004. VOA's Carol Pearson takes a look at what it might take to actually have an AIDS-free generation.

Video With HIV, Can We Get to Zero?

The theme of this year's World AIDS Day is "Getting to Zero." The U.N. says new HIV infections have been reduced by 35 percent since 2000 and AIDS-related deaths are down by 42 percent since the peak in 2004. VOA's Carol Pearson takes a look at what it might take to actually have an AIDS-free generation.

Video Political Motives Seen Behind Cancelled Cambodian Water Festival

For the fourth time in the five years since more than 350 people were killed in a stampede at Cambodia’s annual water festival, authorities canceled the event this year. Officials blamed environmental reasons as the cause, but many see it as fallout from rising political tensions with a fresh wave of ruling party intimidation against the opposition. David Boyle and Kimlong Meng report from Phnom Penh.

Video African Circus Gives At-Risk Youth a 2nd Chance

Ethiopia hosted the first African Circus Arts Festival this past weekend with performers from seven different African countries. Most of the performers are youngsters coming form challenging backgrounds who say the circus gave them a second chance.

Video US Lawmakers Brace for End-of-Year Battles

U.S. lawmakers are returning to Washington for Congress’ final working weeks of the year. And, as VOA's Michael Bowman reports, a full slate of legislative business awaits them, from keeping the federal government open to resolving a battle with the White House over the admittance of Syrian refugees.

Video Taiwan Looks for Role in South China Sea Dispute

The Taiwanese government is one of several that claims territory in the hotly contested South China Sea, but Taipei has long been sidelined in the dispute, overshadowed by China. Now, as the Philippines challenges Beijing’s claims in an international court at The Hague, Taipei is looking to publicly assert its claims. VOA’s Bill Ide has more from Beijing.

Video After Terrorist Attacks, Support for Refugees Fades

The terrorists who killed and injured almost 500 people around Paris this month are mostly French or Belgian nationals. But at least two apparently took advantage of Europe’s migrant crisis to sneak into the region. The discovery has hardened views about legitimate refugees, including those fleeing the same extremist violence that hit the French capital. Lisa Bryant has this report for VOA from the Paris suburb of Cergy-Pontoise

Video Syrian Refugees in US Express Concern for Those Left Behind

Syrian immigrants in the United States are concerned about the negative tide of public opinion and the politicians who want to block a U.S. plan to accept 10,000 Syrian refugees. Zlatica Hoke reports many Americans are fighting to dispel suspicions linking refugees to terrorists.

Video Thais Send Security Concerns Down the River

As Thailand takes in the annual Loy Krathong festival, many ponder the country’s future and security. Steve Sandford reports from Chiang Mai.

Video Islamic State Unfazed by Losses in Iraq, Syria

Progress in the U.S.-led effort to beat Islamic State on its home turf in Iraq and Syria has led some to speculate the terror group may be growing desperate. But counterterror officials say that is not the case, and warn the recent spate of terror attacks is merely part of the group’s evolution. VOA National Security correspondent Jeff Seldin has more.

Video Belgium-Germany Border Remains Porous, Even As Manhunt For Paris Attacker Continues

One of the suspected gunmen in the Nov. 13 Paris attacks, Salah Abdeslam, evaded law enforcement, made his way to Belgium, and is now believed to have fled to Germany. VOA correspondent Ayesha Tanzeem makes the journey across the border from Belgium into Germany to see how porous the borders really are.

Video US, Cambodian Navies Pair Up in Gulf of Thailand

The U.S. Navy has deployed one of its newest and most advanced ships to Cambodia to conduct joint training drills in the Gulf of Thailand. Riding hull-to-hull with Cambodian ships, the seamen of the USS Fort Worth are executing joint-training drills that will help build relations in Southeast Asia. David Boyle reports for VOA from Preah Sihanouk province.

Video Uncertain Future for Syrian Refugee Resettlement in Illinois

For the trickle of Syrian refugees finding new homes in the Midwest city of Chicago, the call to end resettlement in many U.S. states is adding another dimension to their long journey fleeing war. Organizations working to help them integrate say the backlash since the Paris attacks is both harming and helping their efforts to provide refugees sanctuary. VOA's Kane Farabaugh reports.

VOA Blogs