It is a century now since Darwin gave us the first glimpse of the origin of species. We know now what was unknown to all the preceding caravan of generations: that men are only fellow-voyagers with other creatures in the odyssey of evolution. This new knowledge should have given us, by this time, a sense of kinship with fellow-creatures; a wish to live and let live; a sense of wonder over the magnitude and duration of the biotic enterprise.

Our probable ancestors, Homo erectus and Homo habilis -now extinct- are classified as of the same genus (Homo) but of different species, although no one (at least lately) has attempted the appropriate experiments to see if crosses of them with us would produce fertile offspring.

It's sapiens to be homo.

Seventy thousand years ago, homo sapiens was still an insignificant animal minding its own business in a corner of Africa. In the following millennia it transformed itself into the master of the entire planet and the terror of the ecosystem. Today it stands on the verge of becoming a god, poised to acquire not only eternal youth, but also the divine abilities of creation and destruction.

We were rooted in the archaic past, nothing radical about us, our bodies, or needs had changed since the first human saw the light of day somewhere in Africa forty thousand years ago or however long Homo sapiens had existed. But we imagined it was different, and so strong was our imaginative power we not only believed that but we also organized ourselves accordingly, as we sat getting drunk in our cafés and darkened clubs, and dancing our dances that presumably were even more clumsy than those performed, shall we say, twenty-five thousand years ago in the glow of a fire somewhere along the Mediterranean coast.

Humans are the first self-modifying species in this little corner of the universe.

Modern humans appeared some 200,000 years ago. Human activity began to change Earth’s carbon balance roughly 200 years ago. Then, just a bit over twenty years ago, the World Wide Web created the potential for humans to communicate, think, and act as a planetary species with a collective awareness of the global impact of our presence.

We are inescapably the result of a long heritage of learning, adaptation, mutation and evolution, the product of a history which predates our birth as a biological species and stretches back over many thousand millennia... Going further back, we share a common ancestry with our fellow primates; and going still further back, we share a common ancestry with all other living creatures and plants down to the simplest microbe. The further back we go, the greater the difference from external appearances and behavior patterns which we observe today.

Some 3.6 million years ago, in what is now northern Tanzania, a volcano erupted, the resulting cloud of ash covering the surrounding savannahs. In 1979, the paleoanthropologist Mary Leakey found in that ash footprints - the footprints, she believes, of an early hominid, perhaps an ancestor of all the people on the Earth today. And 380,000 kilometers away, in a flat dry plain that humans have in a moment of optimism called the Sea of Tranquility, there is another footprint, left by the first human to walk another world. We have come far in 3.6 million years, and in 4.6 billion and in 15 billion.

For we are the local embodiment of a Cosmos grown to self-awareness. We have begun to contemplate our origins: starstuff pondering the stars; organized assemblages of ten billion billion billion atoms considering the evolution of atoms; tracing the long journey by which, here at least, consciousness arose. Our loyalties are to the species and the planet. We speak for Earth. Our obligation to survive is owed not just to ourselves but also to that Cosmos, ancient and vast, from which we spring.

Looking back, we may remember the human race as the race to build the AI.

If [the emergence of the human species] was unique, as may perhaps have been the appearance of life itself, then before it did appear its chances of doing so were infinitely slender. The universe was not pregnant with life nor the biosphere with man. Our number came up in the Monte Carlo game.

These sites provide clues to the behaviour of early humans. The people who lived here were of the Homo sapiens species and there are signs that they lived as hunters as opposed to scavengers, as may have been the case with other human species such as Homo erectus and Homo ergaster.

Humans lived for several million years as fully wild beings: only in the last 10, 000 did we invent agriculture; only in the last couple of centuries did we invent industry. We are a species that has spent 99 per cent of its history as hunter-gatherers. We haven't had time for our unconscious minds and our unconscious needs to have changed. If you like, our souls have not changed, and this is true whether or not we believe that we have them.

Since the dawn of time, several billion human (or humanlike) beings have lived, each contributing a little genetic variability to the total human stock. Out of this vast number, the whole of our understanding of human prehistory is based on the remains, often exceedingly fragmentary, of perhaps five thousand individuals. You could fit it all into the back of a pickup truck if you didn't mind how much you jumbled everything up, Ian Tattersall, the bearded and friendly curator of anthropology at the American Museum of Natural History in New York, replied when I asked him the size of the total world archive of hominid and early human bones.
The shortage wouldn't be so bad if the bones were distributed evenly through time and space, but of course they are not. They appear randomly, often in the most tantalizing fashion. Homo erectus walked the Earth for well over a million years and inhabited territory from the Atlantic edge of Europe to the Pacific side of China, yet if you brought back to life every Homo erectus individual whose existence we can vouch for, they wouldn't fill a school bus. Homo habilis consists of even less: just two partial skeletons and a number of isolated limb bones. Something as short-lived as our own civilization would almost certainly not be known from the fossil record at all.
In Europe, Tattersall offers by way of illustration, you've got hominid skulls in Georgia dated to about 1.7 million years ago, but then you have a gap of almost a million years before the next remains turn up in Spain, right on the other side of the continent, and then you've got another 300,000-year gap before you get a Homo heidelbergensis in Germany and none of them looks terribly much like any of the others. He smiled. It's from these kinds of fragmentary pieces that you're trying to work out the histories of entire species. It's quite a tall order. We really have very little idea of the relationships between many ancient species which led to us and which were evolut