We are the last humans. What are we going to do with that responsibility?

The revelation this week that a new species of extinct human – H. naledi – has been found in South Africa begs a whole lot of questions.

For me, it also reinforces the responsibilities we have today as humans. It’s like this. Some 737 bones totalling 15 near-complete skeletons were found in what seems to be a paleolithic graveyard. The interesting thing is their apparent intellect. There is evidence that they had spiritualism, because they seem to have had cultural mechanisms – involving massive effort – to dispose of their dead. The way they did it – carrying their dead deep into a hard-to-enter cave complex – also implies they had full control of fire, for light.

Holotype specimen of H. naledi, Berger et al, Creative Commons 4.0 license via Wikimedia.
Holotype specimen of H. naledi, Berger et al, Creative Commons 4.0 license via Wikimedia.

All of which is another question mark over the conceit that the things modern humans use to define ourselves are unique to us. That includes recursive logic, speech, abstract belief (religion/spiritualism), storytelling and creative thinking, all of which are meant to be consequential on our larger brain and reflecting some sort of innate superiority as a species.

But maybe they’re not. It could be we’re simply doing stuff that all human species (as in, genus Homo) did in their own ways. Perhaps the ‘ascent of man’ – often defined as things we do that animals don’t – happened in the Pliocene. Maybe all we’ve done since is a sideways skid. And that’s apart from broader behaviours we already know we share with apes, including a capacity to deceive, which demands substantial intellect, as we define it.

I can attest to that shared ape mind-set on personal experience; there was the time I had a meal with an orang-utan. They look like us, and that’s how they got their name. Orang hutan is Indonesian for ‘Forest Man’. Strictly speaking, they are well distant on the ape family tree. But there was no doubt to me that the orang-utan was just as self-aware as I was, shared the same basic body-language, and knew exactly what he was doing. He also selected healthier food than me, but hey… OK, things are a lot more sophisticated than my brief observations. But it highlights the point.

It’s taken a while to get to that thinking, though that’s not surprising. Nineteenth and twentieth century ‘progressivism’ portrayed our evolution as an ‘ascent’ up the brain-power ladder, which was defined by equating ‘intelligence’ with ‘ability to build Europe’s industrial technology’, and with a number (‘IQ’) obtained by arbitrary culture-centric testing. Everything else was ‘primitive’, ‘less evolved’, and couldn’t do what we did.

Evidence ranging from the discovery of Neandertal musical instruments and artificial epoxy resins (which they invented and manufactured) to burial sites for H. heidelbergensis suggests that, actually, our self-attributed ‘uniqueness’ was just a conceit. The fact that our cousin species hadn’t invented Gatling guns and middle-class gentlemans’ clubs didn’t mean they they were so dull-witted that they couldn’t.

But the mythology has taken a long time to shed. The idea of H. sapiens exceptionalism held sway as recently as the 1980s, when I was studying human evolution as part of my undergrad degree in anthropology.

Skull comparison of early genus Homo specimens. Chris StringChris Stringer, Natural History Museum, United Kingdom, Creative Commons 4.0 license, via Wikimedia.
Skull comparison of genus Homo specimens (Habillis and Erectus c 1.8 mya, Floresiensis c 20,000 BP). Chris Stringer, Natural History Museum, United Kingdom, Creative Commons 4.0 license, via Wikimedia.

In many ways this was understandable. Back in the 1980s, self-exceptionalism was dying a very, very slow death. With the exception of Neandertals, human evolution was known only through a small number of remains, hardly any of which had produced a whole skeleton (‘Lucy’ and ‘Turkana Boy’ were the exceptions, and even they were incomplete). This was fertile ground for open warfare between academics.

More crucially, there was also the fact that Earth today has but one species of human – us.

Neanderthal family group approximately 60,000 years ago. Artwork by Randii Oliver, public domain, courtesy NASA/JPL-Caltech.
Neandertal family group approximately 60,000 years ago. Artwork by Randii Oliver, public domain, courtesy NASA/JPL-Caltech.

That point had been well known since the nineteenth century, and from that perspective it seemed axiomatic that there had only ever been one species of human at any time (except for Neandertals) – that each had evolved into the next (except Neandertals) at the expense of the old. This need to rationalise discoveries to ‘one type at any one time’ drove the main human evolutionary model of the 1980s, which was that humans (by a mechanism unknown to the rest of biology) simultaneously evolved into totally identical forms in widely dispersed parts of the world – the  ‘multi-regional’ hypothesis.

To a large part the theory was an attempt to account for the fact that both older and modern human types had been found in places like Java, but where evidence for multiple ‘waves’ out of Africa hadn’t been found. Of course those multiple waves have since been identified – totally demolishing multi-regionalism. We’ve also sequenced the Neandertal genome – identifying the evolutionary reality of that species relative to us – and now have evidence to show that much of what we supposed was unique to modern humans was possible for other human types.

Homo erectus georgicus, reconstruction and photograph by Élisabeth Daynes. Creative Commons 3.0 license, via Wikimedia commons.
Specimens of H. erectus have been found from Britain to Java, and the species seems to have been fairly variable, giving rise to sub-classifications. The species flourished from 1.8 million years ago. This is a scientific reconstruction of a female Homo erectus georgicus, reconstruction and photograph by Élisabeth Daynes. Curiously, the cliche ‘heavy eyebrow/mandibular prognathic jaw’ popularly used to identify ‘primitive’ humans came later. Creative Commons 3.0 license, via Wikimedia commons.

We now know:

  1. Just one species of human exists today, but that’s new – H. sapiens appears to be a lone survivor of a late-Pliestocene diaspora in which four closely related types (H. sapiens, H. neanderthalis, Denisovans and Red Deer Cave people) co-existed alongside more distant cousins such as H. florienisis (the ‘Hobbits’).
  2. Other human species weren’t automatically doomed at the hands of ‘superior’ H. sapiens. They did the same things we do. It seems that what counted wasn’t cranial capacity, but the way it was organised.
  3. Anatomically, humans have been virtually the same from the neck down since H. erectus appeared 1.5 million years ago. Their brain-size was at the lower end of the modern average range. It turns out there isn’t any automatic imperative in genus Homo to expand brain size. However, H. erectus cooked their food – meaning jaw muscles didn’t have to be so powerful. And they were tool makers, which became a mechanism in which the circuitry responsible for co-ordination (particularly) and planning was selected for. Both factors expanded brain size, but how that influenced intelligence is less clear.
  4. Each species of human didn’t automatically supplant the others, any more than lions supplanted tigers or bonobos supplanted chimps. Humans were subject to environmental-change pressures just like every species, and in the end all species of humans except ours died out. However, until recent times (meaning, up to about 50-20,000 years ago) a number of different types existed, not just H. sapiens’ immediate cousins but also more distant relatives such as H. floresiensis.
Homo heidelbergensis, thought to be the ancestor of H. sapiens, Neanderthals and Denisovans. Photo: Jose Luis Martinez Alvarez, Creative Commons 2.0, via Wikimedia Commons.
Homo heidelbergensis, thought to be the ancestor of H. sapiens, Neanderthals and Denisovans. Brain size was within the modern range. Photo: Jose Luis Martinez Alvarez, Creative Commons 2.0, via Wikimedia Commons.

So it turns out that modern humans aren’t exceptional in the ways we imagined. And it also seems clear we didn’t survive because of some kind of ‘natural’ superiority. It increasingly looks as if our survival when the global climate went bad was more luck than anything else. In fact we came very, very close to going out totally about 70,000 years ago – that’s why every human alive today is VERY closely related, genetically. All. No exception. If we were dogs, we’d be a single breed. All of us. There’s a genetic marker carried by all humans outside Africa that makes clear that all are descended from a very small migratory population. Diversity within Africa is slightly larger, but not in any meaningful way. The original stock, we think, are the Kho’san – Nelson Mandela’s people.

The reality, then, is that we are all humans together – and not just all humans together, but the last humans.

The obvious question is what we are going to do with that responsibility. We’ve always supposed we’re exceptional. It seems that we’re not.

Instead, we’re the last survivors of a whole genus – Homo – who did something that no other creature on Earth ever did. Which is to be smart. And so we carry a tremendous responsibility.

Is there something we can do to preserve that – as the last carriers of that torch? Something that will make us exceptional? Meaning – can we overcome the limits of our human nature – the limits that are driving us towards damaging our environment past the point where it will support us. The limits that make us fight each other for reasons that, in hindsight, seem stupid. We have opportunity to change things. And the recipe isn’t difficult. All we have to do is think, reason and be reasonable, be tolerant, and to understand each other not as threats but as fellow humans – and move forward together.

Like all humans, we’re smart. We have the capacity if we want. I hope we will make the effort.

Copyright © Matthew Wright 2015


30 thoughts on “We are the last humans. What are we going to do with that responsibility?

  1. What you say in the last three paragraphs is exactly the subject of my SF books, which are underlaid by my version of future history – a coming Dark Age followed by a renewal of human culture, where humans really have to pull themselves up by their internal boot straps. So far my books are all laid in the 28th or 30th century, in what I hope comes through as a more enlightened but not utopian version of society.

    1. Sounds fascinating! I agree – the way we’ve gone (which I suspect is a survival technique from the last ice age that doesn’t work on large scale) there’s likely to be a collapse. If we survive it – hopefully the lesson will show us a new way.

    1. It’s a long-standing interest of mine – not just the origins of humanity and the human condition, but also thinking about how we think about it (total recursiveness there!). There’s some excellent work being done on this field these days – the evidence has allowed us to move on from some of the disputes of the twentieth century. I’ll be interested to see what Jerry Coyne has to say about H. Naledi, if he posts on the discovery.

      1. I find all this stuff fascinating too – I wish I’d studied it. I did think about it, but I’m one of those people who’s interested in too many things and isn’t very good at focusing on just one and sticking to it for a while. There’s no reason I couldn’t do a post-grad diploma for any subject available extramurally via Massey except time.

        Jerry has posted about this – you must have been so busy you missed it: https://whyevolutionistrue.wordpress.com/2015/09/10/a-new-species-of-hominin-hits-the-news-what-is-it-and-what-does-it-mean/

        1. I did miss it – thanks for the heads-up. On reading it I see he made the same point I did about sparse fossils creating disputes between academics for status reasons.

          I usually read Jerry’s blog but social media has been on back burner for me of late.

    1. I wonder too. Fairly often, as it happens…There’s an aphorism usually attributed to Einstein – ‘Only two things are infinite. The universe, and human stupidity. And I’m not sure about the universe.’

  2. I remember reading about this discovery not long ago. You covered the topic well; it’s one that fascinates me. The Neanderthals even play a small part in the fantasy world I created. I might be that our greatest gift is the ability to pass along information from one generation to the next. How advanced would we be if we couldn’t build upon what was already learned? At the same time, we also have an uncanny knack for failing to learn from our mistakes and we too often display a self-destructive arrogance. I’ve long believed we don’t own this planet, nor are we its masters. Instead, we’ve inherited a great responsibility to act as its caretaker for the betterment not of ourselves, but of the planet itself and all life that lives on it. We’re failing miserably.

  3. Absolutely fascinating post! I’ve been reading about the cave where they found the bones, and it really does boggle the mind how H. naledi people even found this spot in the first place and what the significance was of depositing the bodies there. Just amazing!
    Your last few paragraphs in this post are powerful. I only wish more people in positions of power would take your viewpoint of Earth and our role in caring for it.

    1. Thank you! Yes, I wish people would start thinking about the responsibilities we have as a species – and the obvious way of tackling the problems we make for ourselves, as a species. Kindness to each other isn’t rocket science!🙂 Thanks again.

  4. Great post, Matthew. Fascinating and informative. I often tell my friends that we haven’t come very far since our caveman days. I think perhaps I’m right. I’m afraid I have limited hope for us as a civilization. I wonder how bad it has to get before we use these magnificent brains and whether it will be too late. I hope not.

    1. Thank you. I hope it’s not too late too. What worries me is that we may not see what’s happening even as the waters of our doom close over our heads. But – optimistically – we will be able to use our intelligence to change things before then.

  5. This discovery is significant, especially because many individuals are represented. I’ve often wondered how a species could be defined on the basis of a single bone. As to us, well, in bad moments I’ve wondered if our brains have developed to a point that they’ve become pathological and will result in our self-destruction. From the planet’s point of view that might be a Good Thing; the problem is what we’ll destroy along with ourselves. I’ve also found myself wondering if those wacky ideas about us coming to Earth from somewhere else might be true — it’s almost as though we evolved on a more robust planet, and this one is too fragile for us. But here we are going beyond science into science fiction. Thanks for a thought-provoking post.

    1. Thanks for your support. I agree – there are things we do, as a species, that seem absolutely pathological. I suspect it’s a survival mechanism from the hard times of the Older and Younger Dryas which (I speculate!) may well have been the key to our survival when our cousin humans died out. But it’s past its ‘use by’ date now. I think SF probably has ways of showing this up – it always was a device for revealing what was adrift (but also what was right) with humanity!🙂

  6. Your post brought to mind those lines of the poet Henry King

    “LIKE to the falling of a star,
    Or as the flights of eagles are,
    Or like the fresh spring’s gaudy hue,
    Or silver drops of morning dew,
    Or like a wind that chafes the flood,
    Or bubbles which on water stood:
    Even such is man, whose borrowed light
    Is straight called in, and paid to night.
    The wind blows out, the bubble dies; The spring entombed in autumn lies; The dew dries up, the star is shot; The flight is past, and man forgot”.

    Despite the above I believe that with good-will and hard work humanity can survive. Kevin

  7. Frankly, I think we’ll screw it up like we have done with the species that reside here with us. We are generally greedy – not smart. We think of our own comforts not the general well-being. So, yup – I think we’re going to mess up the works eventually and end up starting over from scratch.

  8. Interesting stuff, Mathew. I can’t comment on the science because I’ve never studied it, but maybe we aren’t the winners of a competition, maybe we are the thin end of the wedge, one event away from extinction.

    I shall now go and do something good with the rest of my day, just in case!

    Cheers

    Nigel

    1. I think we are indeed not far from going out – not in any immediate sense such as your and my lifetimes, or even anytime in the next few centuries. But if we carry on as we are it will happen soon on the scale of our evolutionary history. Yeah, I’m off to do something useful now too!

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