The ecological disaster of Homo sapiens

I’m finally heeding all the recommendations and reading Yuval Noah Harari’s Sapiens: A Brief History of Humankind.  Harari is an excellent writer, and though at times he seems to present some unproven hypotheses as proven fact, and nine years after initial publication some of the information feels a bit dated, he makes up for it by making the story of humanity read like an epic saga across the millenia.

So far, I’ve only read the first section: The Cognitive Revolution, which goes over what is known about pre-agricultural humanity.  Harari is clear on how little we actually do know about the cultures of prehistoric hunter gatherers, except to note that they were probably very diverse.

What is clear however, is how Homo sapiens spread out of African some 60,000-70,000 years ago and subsequently throughout the globe.  Of note, earlier human species, such as Homo erectus, the Neanderthals, and Denisovans, had spread throughout Eurasia, but none had made it to Australia, the Americas, or the hundreds of islands Homo sapiens would eventually inhabit.

What’s striking is what happens in the paleontological record once Homo sapiens enter a region.  We’ve discussed before that Neanderthals in a particular region disappear within a few millenia after Homo sapiens show up.  What’s been less discussed is the overall large wave of extinction in megafauna, large animals, that takes place once Homo sapiens move in.

It’s particularly striking in places like Australia, the Americas, and island habitats.  Animals such as six foot kangaroos, marsupial lions, giant koalas, dragon-like lizards, mammoths, mastodons, bear-sized rodents, and a variety of other creatures all disappear within a few millenia after Homo sapiens arrive.  In Eurasia, earlier human species had existed for over a million years, and the animals had already learned to avoid human shaped creatures.  But the animals beyond Africa and Eurasia didn’t have the chance to evolve that fear before they were gone.

Some researchers have tried to blame the extinctions on climate change, but as Harari discusses, the climate is always changing, yet it’s a consistent pattern that species that had survived for millions of years disappear in a region shortly after Homo sapiens come on the scene.

None of this is to say that the prehistorical humans entering these areas were being immoral with their actions.  They were simply hunting the available food.  They didn’t have a comprehensive view the ecosystem.  There were no written records.  The population of particular animals species probably didn’t drop that much in any one person’s lifetime.  And by the time the last of a species were killed off, they would have been very rare, with the person killing that last member of a species unaware of the significance of what they were doing.

It’s only recently that we’ve come to appreciate our effect on those ecosystems, and the danger of species extinction.  Which means we shouldn’t take comfort from the fact that we’re just continuing what our forebears have always done.  They didn’t understand what they were doing.  We don’t have that excuse.

29 thoughts on “The ecological disaster of Homo sapiens

  1. If only I could believe that our newfound awareness of the problem would change our response to it. But so far, there’s little evidence of that. Even with species whose disappearance would clearly be worse for the humans who pose the main threat – think overfishing – achieving the establishment of enforceable rules that could preserve the species is like pulling teeth.

    Organisms who aren’t so tasty and nutritious, but just happen to have habitats which humans want to pave over or replace with grazing areas, are probably out of luck.

    Liked by 1 person

    1. That awareness is in the mix, but yeah, it has to compete with economic interests, interests which are easy to dismiss as greedy or short sighted if we’re not the ones feeling them. Everyone complains that the rent is too damn high, or the cost of living too high, but overlooks (or refuses to acknowledge) the fact that lowering them often means trouble for the natural world.


  2. I think I’ve been pointing out for a while how qualitatively different the humans were that came out of Africa around 60-70,000 years ago. Technology, of course, but a much better organized species. There may also be something to the dopaminergic mind hypothesis of Frank Previc.

    Liked by 1 person

    1. Can’t say I’m familiar with that one. But something dramatic seems to have happened within the last 100,000 years. It might have just been a critical mass of prior developments that led to what now looks like new symbolic and more sophisticated behavior. There are earlier examples of symbolic artifacts but they tend to be very sparse and are often controversial.

      Liked by 1 person

    1. We definitely can be. It’s worth noting that we’re not really doing anything any other species wouldn’t have done in our place. The question is whether we can learn to rise above our short term interests to take care of our long term ones.


      1. The question is whether we can rise above other species. All other species. You are absolutely right however. But we should take into account the interests of all life. Not just our own. Sentient or otherwise. Partly because we need a diversified biosphere. Partly because it seems meet and right so to do!


        1. It’s be nice if we took into account the needs of the whole biosphere for purely altruistic reasons, but as you note, even if we’re only being selfish, enlightened self interest requires that we take a broader view.


  3. We now are dimly becoming aware of our effects on the planet: the world is fundamentally changing in every way. We live in a so-called anthropocene.

    Morality is purely in the eye of the ignorant beholder.

    The ultimate question is how do we take charge of our future? I don’t see an obvious answer. The coarse political maneuverings of the various groups seems chaotic

    Liked by 1 person

    1. It seems like politics are always chaotic. The only way to avoid that chaos is with authoritarianism, but that rarely turns out to be in everyone’s interests. Jostling and positioning of everyone to promote their interests is what our form of government is supposed to facilitate.

      The problem is we’ve gotten into a mode where everyone outside our own alliance is not just promoting different interests, but is deemed stupid, vile, and evil. Often you can compromise with different interests by just splitting the difference, but compromising with those we’ve convinced ourselves are villains is much harder.


  4. I remember when I read Moby Dick, there was a part about how the ocean provides infinite resources. No matter what humans do, there will always be more fish, more whales, etc. And I doubt anyone in 1851 would have argued against that point. It really is a very, very, very recent thing for us humans to realize the damage we’re capable of doing.

    Liked by 1 person

  5. Well summarised I thought. Thank you for sharing this important information. Especially as many of us caught up in everyday life don’t always have the luxury of reading each interesting and important book published. Look forward to reading more.


  6. It’s been a while since I read that book…I can’t believe I don’t remember the part you’re talking about here. Interesting. I guess big creatures made big targets?

    Have you gotten to the part about currency? I gobbled that up. I can’t tell you how many times I’ve wondered how money came about.

    Liked by 1 person

    1. I have gotten to that part. Money, the thing everyone believes in, mainly because they know everyone else believes in it. Everyone believes in it, and many hate it. And yet, the alternative would be too have an utterly unworkable barter economy.

      Liked by 1 person

      1. Amazing stuff, money. Even more so now that it’s just numbers on a computer screen. Still boggles my mind. I keep thinking currency ought to have inherent value, but things that do tend to be problematic/inconvenient. Still, though, wouldn’t it be nice if we traded in chocolate bars? Then if the economy tanked, at least we’d have chocolate. Of course, it would be melted or chalky chocolate…okay, there goes that idea.

        Liked by 1 person

        1. Nope, we can’t have chocolate as money. I’d eat all mine and have to declare bankruptcy!

          I’m now in the chapter on capitalism, where he describes the role of banks. I have a business degree, so the multiplier effect is old news to me, but I suspect anyone who hadn’t encountered it before would be surprised (perhaps alarmed) to discover how the banking system actually works.

          And I knew one of the components of economic growth was research and development. But I’d never put together that trust in progress that comes from science is what enables economic growth and the banking system to work. Pretty fascinating.

          Liked by 1 person

          1. It’s all based on trust to an unnerving degree. It’s why when trust erodes, we have recessions. Modern economies have lifted us out of lives of brutish toil, but left us vulnerable to the whims of mass psychology.

            Hmmm. Not the gold standard but the chocolate standard. A return not to hard currency (who needs that) but tasty currency. You might be on to something here!

            Liked by 1 person

  7. This book helped put into perspective the conversation that we are having today about the extinction of current species. It’s kind of difficult to fathom that many of today’s species will actually cease to exist, but in a historical context this is what has happened and what will continue to happen.

    In addition, the idea of reviving extinct species using current genetic technologies may seem unnatural, but to keep in mind that the only reason a lot of them are extinct is because of us. This book definitely made me consider new perspectives.

    Liked by 1 person

    1. Thanks for stopping by! It’s definitely a fascinating book. I enjoyed it.

      On bringing back extinct species, I’m not sure. It seems like we have to be careful not to cause ecological issues for the species that are still alive today. But the technology will open up all kinds of possibilities.

      Liked by 1 person

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