PREHISTORIC MYSTERY: Mastodons feeding on black ash trees. The disappearance of such megafauna has perplexed scientists.
Image: COURTESY OF BARRY ROAL CARLSEN, UNIVERSITY OF WISCONSIN-MADISON
Before humans arrived, the Americas were home to woolly mammoths, saber-toothed cats, giant ground sloths and other behemoths, an array of megafauna more impressive than even Africa boasts today. Researchers have advanced several theories to explain what did them in and when the event occurred. A series of discoveries announced in the past four weeks, at first glance apparently contradictory, adds fresh details to the mystery of this mass extinction.
One prominent theory pegs humans as the cause of the demise, often pointing to the Clovis people, who left the earliest clear signs of humans entering the New World roughly 13,500 years ago. The timing coincides with the disappearance of megafauna, suggesting the Clovis hunted the animals to extinction or infected them with deadly disease. Another hypothesis supposes that climate was the culprit: it had swung from cold to warm twice, including a 1,300-year-long chill known as the Younger Dryas; such abrupt shifts might have overwhelmed the creatures’ abilities to adapt.
To pin down when the megafauna vanished, paleoecologist Jacquelyn Gill of the University of Wisconsin–Madison and her colleagues analyzed fossil dung, pollen and charcoal from ancient lake sediments in Indiana. The dung of large herbivores harbors a fungus known as Sporomiella , and its amounts in the dung gives an estimate of how many mammoths and other megafauna were alive at different points in history. Pollen indicates vegetation levels, and charcoal signals how many fires burned; the extent of flora and wildfires is related to the presence of herbivores, the researchers say in the November 20 Science. Without megaherbivores to keep them in check, broad-leaved tree species such as black ash, elm and ironwood claimed the landscape; soon after, buildups of woody debris sparked a dramatic increase in wildfires. Putting these data together, Gill and her team conclude that the giant animals disappeared 14,800 to 13,700 years ago —up to 1,300 years before Clovis.
A different study, however, suggests that this mass extinction happened during Clovis. Zooarchaeologist J. Tyler Faith of George Washington University and archaeologist Todd Surovell of the University of Wyoming carbon-dated prehistoric North American mammal bones from 31 different genera (groups of species). They found that all of them seemed to meet their end simultaneously between 13,800 to 11,400 years ago, findings they detailed online November 23 in the Proceedings of the National Academy of Sciences USA.
But if ancient DNA recovered from permafrost is any sign, megafauna survived in the New World millennia after humanity arrived. As the permafrost in central Alaska cracked during springtime thaws, water that held DNA from life in the region leaked in, only to freeze again during the winter. As such, these genes can serve as markers of “ghost ranges” — remnant populations not preserved as fossil bones.
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30 Comments
Add Commentthere is no definately answer to the question,who kill mammoth,according to the essay,but I wonder that how could human beings transport desease to animals...you know,in 10,500 years ago ...or far before it.there exits measely possibility to make some appalling contagious desease like N1H1 or HIV,futuremore,what does Clovis looks like?how do they live?what kind of desease they maybe infected...
Reply | Report Abuse | Link to thisMars,
Reply | Report Abuse | Link to thisThe Clovis culture dates to about 13,000 years ago. These were modern humans, just like you and me. They came to the Americas from Asia. They would have carried a wide variety of diseases, just like any species (viruses , parasites, bacterial infection).
thank you PotatoChip.you are a nice guy..animals are fragile...do Clovis developed culture at that time?I heard from my teacher that countries like China in Asia has 5000 history..really?
Reply | Report Abuse | Link to thisAnatomically modern, that is.
Reply | Report Abuse | Link to thisThe Clovis culture was predominantly pre-agricultural, meaning that they hadn’t domesticated plants or animals. No written language. No written history.
Reply | Report Abuse | Link to thisYou probably mean civilization, not culture. All human populations had some sort of culture. Civilization means cities, commerce, written language and so on.
I made a huge mistake...I mean civilazation,not culture..thank you for your answers,you are quite professional.
Reply | Report Abuse | Link to thisThe title needs to be rewritten. As it is, it asks if mammoths vanished "during humans arrived." Sorry, I'm a proofreader. Sometimes it seems like a curse.
Reply | Report Abuse | Link to thisI don't know...there is just something that tells me they are too far off on this one. It seems more like a fund raising article than a scientific one. If Clovis, or maybe it was humans, brought killer disease to America and killed off all the big dangerous animals and all the large consumable ones, wouldn't there be signs of disease in their bones? If a disease killes you, its imprint can always be found in your bone marror and calcum.
Reply | Report Abuse | Link to thisI heard jesus did it.
Reply | Report Abuse | Link to this...when he came to america to hang for a while. you know, while he was on his top secret intercontinental backpacking trip. ...after the jews came over and non-evolved into the native americans around 600bc.
...we almost elected a mormon president.
It doesn't sound convincing that the small group of invasive but mostly harmless primate species - the Clovis or pre-Clovis - killed dozens of species of animals by diseases or hunting.
Reply | Report Abuse | Link to thisIt is also an unproven statement (PotatoChip) that pre-agricultural cultures had no plants domesticated. Maybe they were gardeners, who knows?
The error is the classical confusion of correlation and causality. Even if there is a correlation found of (Pre-)Clovis immigration and extinction of species, many different types of causality would be possible:
- Clovis killed the animals.
- Extinction opened spaces for Clovis to immigrate.
- A common cause killed the animals and lured the Clovis.
- Coincidence - it happened only once, we therefore cannot even derive a correlation from that.
Shouldn’t science adhere to facts and leave groundless speculation to tabloids?
PS: Hunting has the worst ROI of all ways to obtain food. Why should Clovis have done that?
Seems to me that Clovis could not have had the population density that would require so much food that they had to exterminate the megafauna to feed themselves.
Reply | Report Abuse | Link to thisWouldn't animals such as the buffalo and deer have been easier to hunt and more plentiful than the mammoth? I just do not think that the Clovis people had anything to do with the extinction of the megafauna anymore than they were at fault in their own extinction.
The environment was changing at a pace that allowed man to enter the Americas in the first place. The entry of the Clovis culture into North America was a symptom of what was happening, not the cause. When a stable environment is destablized or disappears, the fauna that depend on it will either migrate to other environments or will perish. Man included.
Just my 2 cents worth.
Broadly, if you invest time in gardening, then you tend to stay put year after year. This would be the foundation of an agricultural life style. If you don’t stay put, you don’t have gardens and you don’t spend your time domesticating plants. Pre-agricultural people could have been very wise about harvesting wild plants, but plant domestication is seen as a core element of agriculture and is generally thought to have developed later (say, between 7 and 9 thousand years ago).
Reply | Report Abuse | Link to thisThe artifact most associated with the Clovis culture was the “Clovis point”, which was a chiseled projectile tool used for hunting. There’s no doubt that they were hunters, but since so many species of large mammal became extinct (and since the Clovis people couldn’t have hunted all of them), hunting isn’t a very good explanation.
Diseases that make a cross-species jump generally do so when the species involved live in close proximity. That wouldn’t have been the case here, and it seems unlikely that this would have been a primary factor.
Drastically changing climate makes more sense. It’s a better explanation in that there’s good reason to say that it happened (considering the retreating ice sheets), and that it accounts for widespread effects.
Let's not forget that the animals of the America's also carried viruses, parasites etc. that could have been bad news for the newest species to arrive. Us.
Reply | Report Abuse | Link to thisPeterT
PotatoChip,
Reply | Report Abuse | Link to thisYou wrote: "There’s no doubt that they (Clovis) were hunters"
"No doubt" is IMHO among the most unscientific phrases that one can say.
There is doubt, of course. I doubt it.
I have no idea why I should believe it.
I saw people with weaponry in many countries, and only a very small fraction of <1% were hunters.
The Clovis point may also have been used to defend attack. Maybe to secure gardens and stocks from animals and other humans, just like the American pioneers did?
I have hunters in my family. Hunting is extremely inefficient. Today and even more in the past. Just think about it. A hunter would have to leave the family back home without protectionover many days, would probably come home without prey (shooting distance is under 150 feet) and wouldn't know whether his wife's next child is actually his one.
Agriculture came with the domestication of grasses which are most effective calory producers. We have no idea what humans grew before they had grasses and how they did that. Saying they grew nothing is IMO not a verifiable statement.
I read from some articles which showed how gaint animals like dinasours behave when they are under attack,as far as their shape and weight concerned,the magefauna just can keep in fighting against enenmies in a few minutes ,but in cost of weeks to recover .we can imagine how human beings use their tiny biface weapon to agitate animals and hunted them after they lost their energy...so according to the statement,magefauna are easier to be caught than small animals like buffalo and deer .
Reply | Report Abuse | Link to thisMars,
Reply | Report Abuse | Link to this...and how did these imaginary hunters prevent someone else from impregnating their women and killing their children during these days of absence?
And who brought the hunters who applied this dangerous tactic to hospital when they got hurt? And who ran the hospitals? Who provided blood bottles?
All these ideas are nice and romantic, nothing else,
Archaeologists can tell a lot about the life styles of ancient human groups, including diet. Excavations often reveal bones alongside tools, or a hearth for cooking and so on. Scientists corroborate and cross-reference. They look for common finds at multiple sites. In this case, archaeological digs have turned up Clovis points alongside mammoth bones.
Reply | Report Abuse | Link to thisWhen scientists tell us that the Clovis people were hunters (or numerous other ancient humans that scientists describe as hunter-gatherers), it’s not a guess. Nor is it a romantic idea.
PotatoChip,
Reply | Report Abuse | Link to thisIt is a strange observation I have made quite often: When I talk about my doubts - which is a valid scientific behavior, probably the most fundamental scientific behavior at all - on that topic, I receive the answer: Oh, there is no doubt. I ask "Why is there no doubt?" and the answer is "Because there is no doubt. We know that there is no doubt."
People make me also feel that I am very uncomfortable to them. The "Hunters-Gatherers" is probably a very cosy concept.
The arrow points may be in the mammooths because people have defended themselves, their families or stocks from the animals. Or an ancient blatherskyte loudmouth has shot the arrow in a dead carcasse to then tell his tribe "Hey I did that" and get the nicest tribe daughter as a wife.
Maybe they had an excess of young men and forced them to pass courage tests. Or any other reason.
How can we tell that they did hunting? It may be true or not.
Do you understand the distinction between a "valid presumption" and a "proven fact"?
That early humans went hunting is a presumption and not at all verified.
Extremophile,
Reply | Report Abuse | Link to thisI bet that if Clovis knew what does ROI mean...they would never eager to hunt animals to feed themselves for earning life.
they are too far away from our time ,I think the priority need of them is to be safe and the second is to survive in dangerous environment, you can also learn more from Maslow's theory,which represents the needs of human beings.the bottom of the pyramid is physiological needs such as excretion,eating,sex,drinking,sleeping,shelter,warmth.
that's it...hope it can slove your problem.
mars
The hunting of large animals was most likely done by plunging a point into the flank of the prey,thus risking only one hunter at a time, then letting it bleed out,and following it from a distance,with smaller game being caught with snars and other traps,as for plants there were many types of tubers,fruits, and berrys gathered by women and children with some male protectors along,with the larger group all traveling together.
Reply | Report Abuse | Link to thisExtremophile,
Reply | Report Abuse | Link to thisreally thank you for your harsh question...honestly speaking,I am totally confused about your question,are hunters really bogged down in such an astounding and serious situation?
sorry for my impudent question but I really have no idea about it,would you please show me some facts or statistics about it?by the way ,I am not an American.In my country,few people choose hunting as their job except some ethnic groups which hold it as a kind of tradition,and the government will supply them jobs and make it as conveninent as possible for them to work in their own places.
further more,the government even provide some study chances for hunters' children for partly free to guarantee their offsprings involving in society quickly and qualifiedly competiting with their peers in getting a beneficial job.
I think government acts an important role in helping hunters to live a better life .
about hospitals ..and the cold-blooded people you mentioned above ...I think it may more concerns about morality problem.maybe government intervention can extenuate the bad situation.
God bless hunters and the poor souls.
mars
Mars,
Reply | Report Abuse | Link to thishunters are small minorities in virtually all countries and cultures. Even Inuit are no more an exception to this rule.
I am happy to respond to all your questions and those of other readers, but believe that this is the wrong place for such an in deep discussion. I damaged the cozy world of "Hunters/gatherers" already too much, and I still have collected much more evidence that make the concept seem implausible.
If you send me a mail message, we can do this offline: oliver@oliverlehmann.com.
Extermophile,
Reply | Report Abuse | Link to thisYou Are AN Idiot of the worst magnatude! You present absolutly unrelated comparisons, and obviously are poorly educated, because if you did actually read what is happening in the archaeology world, you would know how we know that our ancestors were hunter gatherers. If you were not so involved in some kind of socio-sexual fear of loosing your exclusive rights to a woman, you would not be assuming that our ancestors wouldn't/couldn't leave their women long enough to hunt and gather food. If you actually had some kind of knowledge regarding our past you wouldn't be asking stupid questions like who whould be taking the hunters to the hospitals. One last slap at the idiot. You stated that grass is far more efficient as a food source than meat....man, I hope your village finds you and does not let the village idiot out again!
I can recommend a good book that touches on the subject "The Early Settlement of North America: the Clovis Era" by Gary Haynes.
Reply | Report Abuse | Link to thisI can recommend a good book that touches on the subject; "The Early Settlement of North America: the Clovis Era" by Gary Haynes.
Reply | Report Abuse | Link to thisScientists which try to find the answer to questions put in article " Lost Giants: Did Mammoths vanish before, during and after human human arrived? " try to simplify events happened on a planet as a whole and on continents in particular; on a site events which www.mammothsenigma.narod.ru are proved occured on continents according to stages I-IV, that allows not to explain destruction of animals in a general plan, and is concrete more in details on stages I-IV
Reply | Report Abuse | Link to thisIn NewZealand the large mega fauna was wiped out in less than a 500 years after the Maori arrived on 7 sea going rafts
Reply | Report Abuse | Link to thisa 1000 ears ago. So humans could have wiped them out, but with the size of North America and the low number of humans I doubt it. If you have ever thrown a spear with a scapel sharp flint point, with a throwing stick you would know it would be easy to kill a Mammoth. Has range and high killing power. If the Clovis came from Asia, then they would be descended from Mammoth hunters, except Clovis points look more European than Asian. Something abrupt happened, digs have shown a very sharp cut off, with plenty of bone deposits, then suddenly nothing, with a brown iron rust layer seperating them. Looks like an iron meteor hit somewhere in the north of Canada, into the ice sheet, so leaving no crater. Looking at any one discipline place will not give the answer. Also there where people down the west coast of North America 18000 years ago so the Clovs are not the first.
That the manmoths seem to have survived longer in Alaska than south because of blockage of the glaciers, might indicate a more interesting possiblity.
Reply | Report Abuse | Link to thisThat the Clovis people did in fact come from Europe and not from Siberia.
Perhaps the Clovis people did wipe out the big game before the glaciers melted enough to allow the Siberians to move in.
Sceptical,
Reply | Report Abuse | Link to thisSeems you saw that program on the History Channel about an astrial body hitting the Canadian glacier and bringing back the Ice Age for a thousand years. They said it caused drought and dust in the south killing off the big herbivores and causing the Clovis people to move west. It was a good show and well documented.
Thing about the Clovis folks is they were not from the east, but from what is now France... Solutrians, based on the point design. Siberians inserted little barbs in a bone.
That be said, I wonder if they served their mammoth with a béchamel sauce. Could be tasty.
Mars, dear sir,
Reply | Report Abuse | Link to thisHumans and animals share contagion that are mutually deadly. HIV, for example came from African monkeys, Syphilis from sheep and salmonella from fowl.
The Conquestidores killed more Mayans and Aztecs with disease than swords. Europeans wiped out 90% of the Hawaiians when they moved in.
Okay, that's human/human transmission. But all mammals share at least 80% of the same DNA and can be subject to the same diseases. Anytime foreigners move into new territory they bring new pathogens the natives lack resistance to.
Entirely possible that humans wiped out the big mammals with the common cold.
But.
I'm prone to the over hunting theory... if you want to get rid of a pesky animal, put them on the menu.
Secondly, the asteroid crash idea holds merit.
Whatever, research will tell