Science Interviews


Sun, 4th Mar 2007

Animal Domestication

Keith Dobney, University of Durham

Part of the show Archaeology and Domestication

Chris - Now tell me where does my humble pooch come from?

Keith - That's a very good question and we're not entirely sure because the ancestor of the domestic dog is as we know now by various studies including genetics, is spread across the entire Eurasian continent so it could come from almost anywhere. The most recent genetic results have suggested that it was domesticated probably Europe, in the near East and certainly as far as South East Asia; eastern Asia into China maybe.

Chris - What does it take to domesticate an animal?

Keith - That's even more of a difficult question to answer, its one that archaeologist and zoo archaeologists have been wrestling with for a long, long time. Originally we kind of assumed - as humans do that we are in control of everything so we decided after thousands and thousands of years of hunting and gathering to go out and domesticate animals because they'd be useful. So we were driving the whole process; going out and capturing them, taming them, selecting them genetically for different kinds of things and making them breed with different individuals so that we could actually get different coat colours. Essentially what we realise now is its a more biological process, which may actually be driven by the animals themselves. The animals are in a kind of mutualistic relationship with humans and they're benefiting hugely from this change in their ecology, habitats and the feeding. So they may have actually been drawn, the wild animals themselves (whether its dogs, or pigs or cattle) may have been drawn to humans and human settlements before we even began to think about taming them and using them for our own economic purposes.

Chris - There was a spin-off for them; if they came and hung around with us they'd get free food and a degree of protection.

Keith - A huge spin-off for them in terms of evolutionary selectivity, they had an enormous advantage over - the ones that came and were tolerating humans nearby and weren't running away quite so fast - had a huge advantage over the same species, the same pigs that were living far away and essentially were wild animals. So they were having access to different food, more food, the presence of humans may have actually kept other kinds of predators away so they had secondary advantages too. If you think about domestic animals today, we take them for granted but they are some of the most successful biological organisms on the planet. They are everywhere, if you think about where sheep are today and where they would've been as wild animals about 10,000 years ago they were restricted to a very small part of the near East and Central Asia now they are everywhere in the world and there are billions of them.

Chris - When do we think that all this major domestication actually happened? What are the major factors that meant that we could get animals growing on farms and that kind of stuff?

Keith - That's a really good question and again I could write tonnes and tonnes of papers on this and people have. It seems to have happened around about 9,000 years ago. Originally it was thought in one or two places, mainly in the near East, the kind of cradle of our civilisation as we know it today. There is evidence that other kinds of animals were being domesticated round about the same time, and then later throughout the world; the same species appears now although we thought differently in the past, like pigs for example that I'm interested in and work on a lot, have been domesticated in many places around the world maybe around the same time. So certainly from about 9,000 years ago, which when you think about it is an incredibly short period of time considering how long humans themselves have actually been around on the planet, so we've been hunting and gathering for three and a half million years and the last ten thousand years is a tiny blip in terms of change in our economics, changing to farming. The spin-off from farming and the spin-off from domestication have been enormous, look around: there are cities, there is culture, there is civilization. That is all down to this series of events which happened incredibly recently.

Chris - So if we were to look at you gave the example of pigs Keith if we look at wild boars, which are the ancient ancestors of the pigs we rear for our Danish bacon today, what would a cow have looked like if you wind the clock back 9,000 years? What would a sheep have looked like nine and a half thousand years ago?

Keith - You mean a wild one?

Chris - Yes.

Keith - The ancestor of all wild cattle, we know now was Bos primigenius, the Aurochs and its now extinct unlike the wild boar and the wolf we still have their present day relations on the planet. So we can use those to study the past ones for things like cattle and dromedary; single humped cattle, we don't have their wild ancestors they've become extinct, so we can only find their skeletons. Bos primigenius, wild cattle were enormous and incredibly dangerous, they were certainly around in Eastern Europe until the 16th Century. We know they were enormous from their bones, we know from other studies that they were ginormous and incredibly dangerous, so one of the questions is why did early people domesticate something so big and so dangerous? It may not have been for economic reasons, there are sites in Turkey for example which have war paintings and temples with these enormous horn cores the horns of these ancient wild cattle, in what we think are ritual and temple contexts. It may well have been that the early domestication of cattle, these huge wild animals was maybe for ritual or religious purposes and not for economics at all.

Chris - What about the sheep question do we know where they came from?

Keith - Yeah we do, sheep still exist as ? So we can see wild sheep. Certainly again, genetic studies have shown the ancestors to be Ovis orientalis (scientific name)this is the Asiatic Mouflon and we can still see those in zoos, we can see them in the wild in parts of the Near East in higher parts of the fertile crescent in areas like Zagros mountains in Northern Iran, Armenia, places like that. They're quite rare now and they would've been in the past , same for goats they were more or less restiricted to the same range as the wild sheep. The ancient Bezoar goat with the very, very, large horns; all domestic goats today are derived from that.

Chris - And just very briefly Keith, one final question. People are very interested in bird 'flu at the moment for obvious reasons and where we think we spawned that from was wild birds, in fact, aquatic birds. So when would that put the origin of human 'flu because for humans? Because for humans to get 'flu they must've been very close to wild birds for a significant period of time.

Keith - Wow that's a question and a half! I was interested to listen to Lawrence earlier in terms of diseases that humans get, obviously this whole process of animals becoming closer in relationship to humans in terms of domestication, so we're controlling them, we're herding them, we're keeping them penned, we're handling them more, we in much closer proximity. He mentioned tuberculosis for example and one of the ideas maybe that tuberculosis in humans may actually be such a problem because it derives from animals, certainly diseases that are found in animals, things called zoonosis, like viruses, like tuberculosis, like a whole range of other things maybe originated very, very early and maybe originated and be the result of this close contact. Bird flu, the problem with those kinds of things, we just cannot see the effects on the skeletons; all we're looking at are bones so we can only find the viruses or maybe the genetics or DNA through the actual individuals themselves, so the bones don't tell us this unfortunately.




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