The good news from Homo naledi: we humans are not alone

http://www.theguardian.com/commentisfree/2015/sep/11/homo-naledi-humans-not-alone-evolution

Version 0 of 1.

One of the curious features of science news is that the excitement it generates bears little or no relation to our ability to understand it. Kudos to you if you can explain to me what a Large Hadron Collider actually is, but anything more precise than “a huge ring under a mountain for smashing particles into each other”, and you’re a member of the cognoscenti. Yes, I know it resulted in the discovery of the Higgs boson, but just because I can say it doesn’t mean I understand it.

A similar kind of uncomprehending buzz has greeted the discovery of the bones of at least 15 individuals in a South African cave system. These may be members of a hitherto unknown species, Homo naledi – perhaps our earliest ancestor, living as long as 4 million years ago.

Related: Homo naledi: new species of ancient human discovered, claim scientists

Not so difficult to understand, you might think. But the significance of the finds can only truly be appreciated if you know your Home erectus and Homo habilis from your Australopithecus afarensis. If not, then – like me – your reaction to the news adds up to little more than: “Wow! We’ve got more funny old relatives! Cool!”

The thing is, it is cool and we’re right to be excited. We might not grasp the scientific significance of the find, but that doesn’t mean we can’t respond to its human importance.

It’s always a kind of magic to find out that there are more things in heaven and earth than we’ve dreamed of. Invention provides the delight of creating new realities, and discovery the thrill of making the previously unseen visible. For most of the modern era the two went hand in hand, but recently they have gone their separate ways. Innovation is progressing at an ever accelerating rate, but the pace of discovery has in some sense slowed. Whereas innovation begets yet more innovation, the more we discover, the less remains to be discovered.

Of course, discoveries are still being made daily, but compared with the leaps of the past they are small matters of detail. In some ways they may be more numerous than ever, but there is little excitement in seeing the footnotes multiplying while the body of the book remains more or less the same.

This means that while we have become somewhat inured to news of the latest technological advances, the currency of genuine new discovery has never been worth more. Digging up a previously unknown kind of early human is thrilling evidence that there is much more left to be found about who and what we are. Far from being nearly over, it turns out our journey of discovery has many miles left to run.

But Homo naledi is not just any old discovery. It is a glimpse into our human past, and the fact that we are choosing to look at it with such delight is telling. Let’s not forget that until quite recently the idea that we were related to primitive species was greeted with horrific disbelief, not wide-eyed wonder. In many parts of the world, it still is. It seems that the bulk of humanity at least has come to terms with the fact that we do not stand outside nature but fully within it, one animal among many, one that evolved like all others.

The reaction to the suggestion that Homo naledi practised ritual burial is also significant. For a long time we took excessive pride in human exceptionalism, dismissing any suggestion that any other species could do the things we do, like use language or make tools. Now we positively relish any discovery that non-humans also play, mourn, communicate or even have a kind of morality. The dignity of human rituals is not threatened by the discovery that some were also practised by our tiny-brained ancestors. We have stopped basing our ideas of human worth on ideas of uniqueness, and in so doing have appreciated more the worth of non-human species.

Until quite recently the idea that we were related to primitive species was greeted with horrific disbelief

However, there is one respect in which this acceptance has still got a little way to go. Although we are happy to allow naledi into the human family, we still disown our living kin. Several years ago scientists from Wayne State University in Detroit argued that, based on DNA, there are currently three species of human: Homo sapiens, Homo troglodytes (chimpanzees) and Homo paniscus (bonobos). There is no scientific basis for lumping the last two in a separate genus, Pan. If we are to come fully to terms with our evolutionary past, then it is time we fully accepted its implications for the present.

To understand our evolved past is to better understand human nature. Ironically, however, that understanding by implication undermines any sense we might have that there is any such thing as fixed human nature. We see this not only over the millennia of biological time, but the decades and centuries of cultural time.

Much as we like to celebrate the fact that all humans are essentially the same, our reactions show that we are not. Homo naledi holds up a mirror not to unchanging human nature: it would reveal very different things to a southern creationist, a Victorian bishop, and a secular 2015 Guardian reader. These bones remind us that it is our nature to change, and that what the human species becomes in the future is at least in part in our own hands.