Humans responsible for demise of gigantic ancient mammals

Aug 17, 2015

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By University of Exeter

Early humans were the dominant cause of the extinction of a variety of species of giant beasts, new research has revealed.

Scientists at the universities of Exeter and Cambridge claim their research settles a prolonged debate over whether humankind or climate change was the dominant cause of the demise of massive creatures in the time of the sabretooth tiger, the woolly mammoth, the woolly rhino and the giant armadillo.

Known collectively as megafauna, most of the largest mammals ever to roam the earth were wiped out over the last 80,000 years, and were all extinct by 10,000 years ago.

Lewis Bartlett, of the University of Exeter, led the research, which also involved the universities of Reading and Bristol and is published in the journal Ecography. He said cutting-edge statistical analysis had helped solve the mystery almost beyond dispute, concluding that man was the dominant force in wiping out the creatures, although climate change could also have played a lesser role.

Read the full article by clicking the name of the source below.

13 comments on “Humans responsible for demise of gigantic ancient mammals

  • Yep, juries in and we are guilty as charged.
    As soon as we moved into a land mass we caused extinctions of the top predators and other mega fauna. Australasia’s a really good example of a smoking gun. The mega-fauna goes out very quickly after we arrive.

    Worse, we are heavily implicated in the extinction of our cousins too as all other human species go extinct not long after we enter their habitat.

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  • This points to the stupidity of our ancestors. What point in killing a mammoth?

    very dangerous. I will hazard a guess that mammoths might be intelligent and might mount group defenses.
    most of the meat will spoil before you can consume it.

    Sounds like ego ran away with our ancestors.

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  • Because they’re abundant, easy to chase off of cliffs with fire, not equipped to deal with thrown spears via evolution, and humans can preserve meat for later.

    Alternatively let’s do a little thought exercise. Since mammoths were similarly sized to elephants that’s about 1000 pounds of meat (Bones, tusks, skin, hair, intestines, etc aren’t edible). Now, a human NEEDS 2000 calories a day if you don’t do a whole lot. If you’re chasing mammoths or actively foraging for food… lets say 4000 a day. That’s about 1-1.25 pounds of meat. A human however can store extra calories as fat so eating 12k calories isn’t unreasonable and eating more is even better from a feast to famine life style stand point. So, let’s say a person eats 3 pounds of meat per day. Now if you have a small group of say… 50 humans eating 3 pounds of meat a day 1000 pounds of meat will only last about 7 days.

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  • It could have been so much worse for the mammoths if our ancestors had invented TV chefs and Waitrose:

    SERVES 40

    20 tbsp sunflower oil
    10 large onion, finely chopped
    2250g wild (or chestnut) mushrooms, wiped clean and sliced if large
    30 fresh sage leaves, finely chopped (to give about 1 tsp)
    10–20 tsp paprika
    3.5 kg tagliatelle
    30 x 200g mammoth or mammoth rump steaks, trimmed of fat and cut into bite-sized pieces
    3.25 l good-quality giant armadillo stock
    50ml brandy (or fermented urine if none available)
    Good few shakes of Worcestershire sauce
    1 kg crème fraîche
    leaves from half bunch of fresh parsley, very finely chopped (to give about 20 tbsp)
    Sea salt and freshly ground black pepper

    Heat 1 tablespoon of the oil in a large frying pan over a low to medium fire. Cook the onion for 4-5 minutes, stirring regularly, until just beginning to soften but not colour. Next, add the mushrooms and sage and paprika and continue to cook for 5 minutes until they begin to wilt. Tip this mixture into a medium pitcher and set aside, reserving the frying pan too.

    Put the pasta on to cook in a large pan of boiling, salted water according to the village elder’s instructions until al dente.

    Return the frying pan to a really blazing fire with the remaining tablespoon of oil and fry the meat pieces for 2–3 minutes, stirring regularly, or until they are brown all over. Tip them into the bowl with the mushroom mix.

    Reduce to a high heat and add the stock, brandy and Worcestershire sauce. This will help deglaze the pan, so scrape any brown bits off the bottom with a wooden spoon for a minute as it bubbles. Season with salt and pepper and leave the liquid to bubble away and reduce down by about a third for 3-4 minutes. Then, reduce the heat to medium and return the meat and mushroom mix to the pan. Simmer for 2-3 minutes to heat through and then add the crème fraîche. Cook for a further minute, stirring. Season to taste, then stir the parsley through and remove from the heat.

    Drain the cooked pasta well and divide amongst hefty serving plates. Spoon the stroganoff over and serve at once.

    TOP TIP If you are using half-fat crème fraîche, then do not let it boil as the crème fraîche will just curdle.

    Drink with a strong bodied Rioja ‘Single Vineyard’ 2013BC Ramón Bilbao

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  • They weren’t singling out Mammoths. The tally of large animals we took to extinction is very long. You can add Sabre tooth’s, terror birds, giant sloths, woolly rhinos, american camels and horses and many others .
    To give data to this:
    When humans arrived in Australia 23 out of 24 large animals vanished in a few thousand years,
    in the Americas its even faster 34 out of 46 large species in just 2 thousand years.
    I don’t think they were deliberately hunting animals to extinction its just that large animals reproduce much slower than smaller ones and you don’t have to kill many in a year to wipe out a herd and there was climate change going on at the same time putting these animals under more pressure.
    Incidentally there is very good evidence that hunter gatherer sapiens were preserving meat in the ice along Siberia and Alaska, so the meat wouldn’t go to waste.

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  • I hate to bring a word of caution to this misanthropic party, but did anyone bother to look at the article? You really should, because it’s freely accessible(-ish), and… It’s dangerously close to being toilet paper. It’s substantially a review article with a dubious bunch of computer simulations smeared on top of it. And it fails to answer a very fundamental question: how large had to be the human population to affect the megafauna to such an extent? If you have a thing you call a model you must get a prediction for the size of the population and then you have to put that number next to either an independent prediction or a direct measurement to claim even the slightest of sense for your conclusions… The article, as far as I can tell, fails at that.
    Given the vast display of human stupidity we can enjoy today, it’s certainly reasonable to think that the arrival of H.S.Sapiens wasn’t good news for any ecosystem. But what we are witnessing today is stupidity to the power of over 7 billions, which is a VERY different problem, sizewise, from stupidity to the power of a few hundred thousands.

    Here’s the link to the paper:

    Science is a great method for gathering knowledge and proving hypothesis… If done correctly. Please turn on your skepticism, especially when evaluating scientific work.

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  • Sure but this on top of decades of similar research. I’m reading a text book on this very subject right now that was published prior to this study.
    Nothing in science is absolutely proven and all theories are ready to be torn down but this is not some wild out of the blue conjecture – its the latest piece in a body of evidence. Even if its badly done that doesn’t invalidate the theory.
    As I pointed out there’s very good evidence for homo sapiens making substantial changes to ecosystem all over the world (due to hunting but even more deliberate deforestation with fire)- you just have to look at the timings. When we arrived in America (as ice retreated)- mass extinction. When we arrive in Australia (35000 years earlier) – mass extinctions. The last woolly mammoths retreated to islands of the north coast of Siberia and survived there for millenia until the first humans show up, then went extinct very quickly.
    The Maori people only landed in New Zealand 800 years ago and within a few hundred years there’s a mass extinction of mega-fauna there too.
    It should also be pointed out that most megafauna species had been through numerous ice ages so to have so many go extinct at the same time requires an explanation that only mankind provides.
    However I don’t take the view that hunter gatherer communities were stupid or bad – they were just doing what they needed to survive. That’s a bit like blaming mosquitoes for malaria.

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  • I’m not saying that the hypothesis sounds unreasonable, nor I’m denying existence of evidence. What I’m saying is that this article doesn’t prove its point. At all. It claims quantitativeness and yet there’s not even a little number.

    I’ve been reading about the topic as well… Not textbooks, but I have. There is some correlation between the decrease in population of large game when the sapienses show up in a place, and it has been attributed to the naiveness of those animals that never saw a human -which is backened by the fact that in Africa, where we evolved, we have to wait for the Europeans and their rifles to see the megafauna really endangered.

    A fact that leads to a question that really should have been answered in the article but was not: how big were those populations of sapienses? Either an answer is provided, a quantitative one, with error bars, please, or a very, very good explanation why the presence of a bunch sapiens can in principle cause the demise of a large species.

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  • I think you are probably right about the animals not having to evolve a way round the threat. However the time scales while tiny in geological terms are still thousands of years. Once they made it through Alaska though they settled the Americas very quickly, maybe in as little as 2000 years – from one end to another. I’m not great at maths but that suggests largish populations. In any case with slow breeding large animals you don’t need huge amounts of predators to send the population into permanent decline. We have the example of peoples like the Maoris and even British sailors more recently sending species to extinction within a short period of time.

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  • I’m not saying that the hypothesis sounds unreasonable, nor I’m denying existence of evidence. What I’m saying is that this article doesn’t prove its point. At all. It claims quantitativeness and yet there’s not even a little number.

    Though I applaud Lorenzo’s demand for mathematical evidence to prove the hypothesis to a near-scientific certainty, or at least to clarify what the researchers are trying to show us using hard numbers that measure the relative human and mammoth populations living in predatory proximity during the pertinent period of extinction -unfortunately no such evidence could possibly exist currently for hard body counts.

    Like jurors in many murder trials, I rely on compelling circumstantial evidence to concur with the research and reach a verdict of “guilty” for Homo sapiens. Other studies correlate the “mysterious” disappearance of mammoths from geographic habitats with the arrival of humans between 30,000 and 20,000 years ago. We should never underestimate the predatory power of the human animal to exterminate diverse varieties of species -birds, fish, game animals. One example stands out in my memory . In the mid to late 19th century there was a species of parrot in the American Southwest including Mexican territory that numbered in the millions. Game and sport hunters arriving on the scene, literally hunted these prolific birds into extinction over several decades. It can be done.

    It’s a little like the O.J. Simpson case (ignoring substantial forensic evidence on the one hand and police procedural screw-ups on the other for the sake of analogy). If he didn’t kill Nicole Smith and her friend then who did?

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  • The researchers ran thousands of scenarios…

    Examining different regions of the world across these scenarios, they found coincidences of human spread and species extinction which illustrate that man was the main agent causing the demise, with climate change exacerbating the number of extinctions.

    “Correlation does not imply causation” is a warning from the study of statistics. Is not the counter-assumption “correlation proves causation” the Questionable Cause logical fallacy?

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