And so the human revolution in the sense of the formation of Homo sapiens, was one thing which happened in Africa and then you have in different parts of the world, in my view associated with the development of sedentism, which is much closer to Gordon Childe's Neolithic or agricultural revolution, and these appeared independently it seems, in Western Asia and in China and in Mesoamerica. Human beings went to all, to all these places and in their different environments, they did their own thing with negligible communications between them in those early days, so communications developed much more recently. So, how do we get a grip on those processes? It's been obvious for a long time ago, since Childe spoke about the Neolithic revolution or the urban revolution as if it was one thing. Well, we can see that the agricultural revolution took place in, took place in different areas, but it still seems to us appropriate to call it “The” Agricultural Revolution. It was lots of revolutions but it was similar. There was sedentism, then there was the development of crop production, where animals were available, they became domesticated, permanent life, development of trade, beginning of value systems, maybe beginning of measurement. Then in some cases an urban revolution, we can call them cities in different parts of world but who authorises the word “city”, a single word for what were completely different manifestations in different places? Well, the only serious approach to that in recent years, I think is Bruce Trigger’s book, "Understanding Early Civilisations", where he set down very carefully to compare seven early civilisations, but I think he made one decision which may not have been the best decision. He decided to restrict himself to civilisations where he had some access to written records. And so he chose in general, very early literate civilisations, and that I think let him into some wrong directions. In particular it caused him to omit the Indus Valley civilisation, which in some ways is anomalous. In many early civilisations, like Ur and like Shang, you have rich burials, princely burials in many parts of the world, the earliest stage of complexity, Egypt, you have the burials of Pharaohs and all this looks very impressive, Moche Peru and so on, yet in the Indus Valley you don't see that. You don't see these very prominent people. And then again, he concludes, no doubt rightly, that in many early civilisations, you have the emergence of religious beliefs, new cosmologies, which link the ruler with the divine. And that I think applies very well in many Mesoamerican civilisations, you can see that happening. And in a different way, but quite a valid way in China, but in, in the Indus Valley civilisation, you just don't seem to find temples. You find great Bath of Mohenjodaro and other very strange and interesting things and maybe some symbolism with those stone lingams that they're supposed to signify the predecessor of the great Lord Shiva, but who knows, you just don't find it. So that I think, we need a much more sophisticated approach and sometimes I think that in archaeology, for all the advances we've made, we're rather like natural history at the time of Linnaeus. And Linnaeus made these wonderful advances and understood that you could begin to classify the world and set up the classification of the living world, but it took Darwin to think in more processual terms about how these different living systems came about. By introducing his notion of natural selection, and then it took Crick and Watson to show us the molecular basis. The DNA basis for the origins of life. Well, I rather wonder if in archaeology we haven't got to the Linnaean stage where we, we've got a good narrative in different parts of the world, we've got very good ways of recovering data from the past. I think that's really quite sophisticated, but we seem to be in a very primitive position, where we scarcely have a framework for comparing what happened in China, with what happened in Peru for instance. Moreover, if we seek to do so, there is one faction among active archaeologists who say - hey, you can't do that, you're ignoring context, you're trying to create laws of culture process. This is mere processual archaeology and we have to be post-processual. Well, I think we perhaps got over that particular debate, but the point I'm making is that we have no intelligent framework for comparing these different experiences, yet the one thing I think we can agree on is that after the out of Africa dispersal, the things that happened in different parts of the world, to some extent happened independently and then of course there were relations across Central Asia, so that the chariots and the Shang Burials are derived from the chariots further west in, in Europe and in the Ukraine, but the Americas were affectively independent from Europe and probably from Eastern Asia until a lot of things had happened and many developments had taken place. So that somehow the archaeological record, offers a whole series of effectively independent inventions of sometimes very much the same thing. And the common ingredient of course, is the human being, and the human being has got very much the same in DNA in all these different places, give or take a few mutations, a few differences in the haplogroups. But the physical basis is very much the same. So we have this wonderful challenge of how do we make sense? Why did these different things occur when they did? Well, part of it is because the same human beings, effectively, a child born today is very much the same as a child born 10,000 years ago in any part of the world. But the child very quickly becomes inculturated and joins a, a culture where there's generations of wisdom and experience together. So these are things that we don't understand and I don't think, I mean, I don't even see any serious discussion about how one could conduct a comparative archaeology or a comparative anthropology. These are the old challenges that the first anthropologists, Lewis Henry Morgan EB Tylor and so on, were addressing, not very successfully, 150 years ago. But we don't really seem to have advanced very much since then in our analytical apparatus. So I, I do see archaeology at a very exiting juncture where all these things are coming about. We're beginning to relate linguistic and genetic evidence, and one could say much more about how the linguistic evidence would mean more if we had a good chronology, we could then think how the vocabularies really give us information and so on. A lot to learn from that, and we've got the advances in neuroscience that may help us to realise how the learning process operates in childhood and so on. But I think we're just like Linnaeus, being able to stick names, labels on things, and really not have much clue yet, how they came about. So I think for a new archaeologist today, it's a very exiting position to be in.