My Google Page Rank

Mammoths wiped out by multiple killers


Woolly mammoths were apparently driven to extinction by a multitude of culprits, with climate change, human hunters and shifting habitats all playing a part in the long decline of these giants, researchers say.

Woolly mammoths (Mammuthus primigenius) wandered the planet for about 250,000 years, ranging from Europe to Asia to North America covered in hair up to 20 inches (50 centimeters) long and possessing curved tusks up to 16 feet (4.9 meters) long. Nearly all of these giants vanished from Siberia by about 10,000 years ago, although dwarf mammoths survived on Wrangel Island in the Arctic Ocean until 3,700 years ago.

Scientists have often speculated over what might have driven the mammoths to extinction. For instance, for years researchers suspected that ancient human tribes hunted the mammoths and other ice age giants to oblivion. Others have suggested that a meteor strike might have drastically altered the climate in North America about 12,900 years ago, wiping out most of the large mammals there, the so-called "Younger Dryas impact hypothesis."

Now an analysis of thousands of fossils, artifacts and environmental sites spanning millennia suggest that no one killer is to blame for the demise of the woolly mammoths.

"These findings pretty much dispel the idea of any one factor, any one event, as dooming the mammoths," researcher Glen MacDonald, a geographer at the University of California, Los Angeles, told LiveScience.

*Mammoth database

Scientists investigated the extinction of woolly mammoths living in Beringia, the last refuge of mammoths that nowadays lies mostly submerged under the icy waters of the Bering Strait. To get an idea of woolly mammoth abundance, past climate and other environmental factors, they analyzed samples from more than 1,300 woolly mammoths, nearly 450 pieces of wood, nearly 600 archaeological sites and more than 650 peatlands, compiling their ages and locations to see how these giants and their environments changed over time. They also probed mammoth genetic data found in fossils of the titans.

"There will be people talking about the incompleteness of the fossil record, and there'll always be uncertainties here, no question, but the size of our database is thousands of data points, so I think we can see the general patterns," MacDonald said.
Their results revealed woolly mammoths flourished in the open steppe of Beringia between 30,000 to 45,000 years ago, with its relatively abundant grass and willow trees. The area wasn't as warm then as today, but not as cold as the height of the ice age. "That seemed to be very favorable for mammoths, in terms of abundance," MacDonald said. Humans coexisted with mammoths back then, clearly not driving them to extinction at that time.

Later, during the iciest part of the ice age 20,000 to 25,000 years ago, the "Last Glacial Maximum," northern woolly mammoth populations declined, likely because the area became too barren to be hospitable. However, during that time, the giants became abundant in the warmer interior parts of Siberia.

"There was an old idea that cold glacial conditions like the Last Glacial Maximum were optimal for mammoths," MacDonald said. "That idea now doesn't really hold water."

*Northern refuge

Northern mammoth populations grew after the Last Glacial Maximum, but then dipped again during the Younger Dryas period about 12,900 years ago. Although there is controversy as to what happened at that time, "there was certainly a very rapid and profound cooling of many regions then, followed by rapid warming," MacDonald said. "Did this cause the extinction of the mammoth? Absolutely not. They were still present in far northern sites at the end of the Younger Dryas. Right now it's not quite definitive how great an impact the Younger Dryas had."

The last mammoths seen on the continents were concentrated in the north. They apparently disappeared about 10,000 years ago as the climate warmed and peatlands, wet tundra and coniferous forests developed, environments to which mammoths were poorly suited. The long-lasting proximity between mammoths and humans suggested that our species was perhaps a factor in the beasts' decline, possibly killing off the final island populations of woolly mammoths that went extinct 3,700 years ago.

Overall, these findings suggest the mammoths experienced a long decline due to many factors.
"There was no one event that ended the mammoths," MacDonald said. "It was really the coalescence of climate changeand the habitat change that triggered [it], and also human predators on the landscape at the end."

These findings regarding mammoths could shed light on what species today might face in the future.
"Mammoths faced profound climate change and very profound changes in their habitat and landscape, and also faced pressure from humans," MacDonald said. "Now think about the 21st century, where we're seeing rapid climate change, massive changes in the landscape and certainly pressure from humans on the environment. Species today are facing the same sorts of challenges the mammoths did, but the rate of those changes today are much greater than what mammoths faced."

Future research can focus on other animals once plentiful across Beringia, such as horse and bison. The scientists detailed their findings online June 12 in the journal Nature Communications.

by Charles Q. Choi

Related news items:
Newer news items:
Older news items:

Prev Next Page:

Understanding the legal status of Sulu Sultanate nation-state (Part V)

23 Nov 2015 Hits:192

It is defined in the International Law that “A State is a community of persons more or  less numerous, permanently occupying a definite portion of territory, having a government of[...] Read more

A brutal double murder in Bunguiao

23 Nov 2015 Hits:181

A mother and a daughter were hacked to death, in a secluded place in Bunguiao, East Coast, by an unidentified person or persons, during the weekend. Barangay eMedia was able[...] Read more

“BG” has new eye-popping edict worth implementing

23 Nov 2015 Hits:163

(PASSAGE of the Day):“If God is for us, who can ever be against us?” (Romans 8:31). Email:****--***--** “BG” INITIATES ONE LAUDABLE PROJECTTHE youngest honorable member, right now, of the[...] Read more

Fatal blade

21 Nov 2015 Hits:195

There was a couple of police reports, two days ago, which were quite disturbing, and both were perpetrated via a fatal blade. The first was about a child, in Vitali,[...] Read more

Obama’s assurances unreliable?

21 Nov 2015 Hits:842

LIFE’S INSPIRATIONS: “… It is time for you to act, Lord;  your law is being broken…” (Psalm 119:126, the Holy Bible).-ooo-OBAMA’S ASSURANCES CANNOT BE RELIED UPON? I really do not[...] Read more

WMSU has seen its own “heartbreaks”

21 Nov 2015 Hits:275

(PASSAGE of the Day):THE real temple of God is the body of a human being free of the serpent seed where God wants to dwell.“Destroy this temple and in three[...] Read more

The grandstand’s rehabilitation plan

20 Nov 2015 Hits:208

The siege of 2013 permanently altered many things locally here in Zamboanga City. Albeit, many of the ordinary Zamboangueños, up to now, are still pretty undecided or undetermined as to[...] Read more

Why are Poe and Chiz leading in surveys?

20 Nov 2015 Hits:235

LIFE’S INSPIRATIONS: “… my people are destroyed from lack of knowledge…” (Hosea 4:6, the Holy Bible).-ooo-WHY ARE POE AND CHIZ LEADING IN SURVEYS? Why is Sen. Grace Poe continuing to[...] Read more

EXPECT a better image of our public market

20 Nov 2015 Hits:156

(PASSAGE of the Day):“Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him.” (1 John 3: 15). Email:***--**--**WHY DESTROY ROADS[...] Read more

What a rainy Wednesday yesterday!

18 Nov 2015 Hits:227

Due to the heavy rains of the early dawn of yesterday—November 18, the CDRRMO-Zamboanga City sent a soft-copy public service to Barangay eMedia as to advice the people, to wit—[...] Read more

Sun ready to burst and burn the heavens?

18 Nov 2015 Hits:211

LIFE’S INSPIRATIONS: “… `If anyone does not remain in me, he is like a branch that is thrown away and withers; such branches are picked up, thrown into the fire[...] Read more

FIGHT like David!

18 Nov 2015 Hits:165

(PASSAGE of the Day):“For God so loved the world that he gave his only begotten Son, that whosoever believeth in him should not perish, but have eternal life.” (John 3:[...] Read more

Bags of Smuggled Rice and Sugar

18 Nov 2015 Hits:183

The baranggay of Talabaan is a cozy outskirt of the City, in the East Coast. One cannot suspect that contrabands can now be found there, even the rated TV host/announcer[...] Read more

THOSE “spillovers”

18 Nov 2015 Hits:165

(PASSAGE of the Day)“Seek ye first the kingdom of God, and his righteousness; and all these things shall be added unto you.” (Matthew 6: 33). Email:—***—**—**THOSE KNOWN “SPILLOVERS”THIS is[...] Read more

“Amen”: one of the Names of God

15 Nov 2015 Hits:197

LIFE’S INSPIRATIONS: “… Yet to all who did receive him, to those who believed in his name, he gave the right to become children of God---children born not of natural[...] Read more

Previous administration not criminally and administratively liable on Magay fire

15 Nov 2015 Hits:232

The burning of the public market in Magay on October 31, 2015 that claimed the lives of 15 persons prompted the city government to conduct an investigation to determine the[...] Read more

It was Ayala National High School

15 Nov 2015 Hits:528

Thursday evening, November 12, the personnel of Barangay eMedia busily discussed amongst themselves, in a meeting, to finally recap the details for an important event which the company, and the[...] Read more

(Sharing Time) THE importance of GOD’s WORD

15 Nov 2015 Hits:178

THERE are other important details that can’t simply be divulged, at all. THEY’RE said to be highly confidential, hence, as they: “These are all for your eyes and ears only.”AND[...] Read more