The history of selective breeding
What it selective breeding, how far it goes back, and what drove it to begin with. To explain is the author of 'Unnatural Selection', Katrina van Grouw.
Katrina - I think it's important to say what selective breeding is not. And it's very tempting to use the word interchangeably with domestication, and I consider these to be two very distinct processes. Domestication is the transformation of wild populations of animals into self-sustaining populations of tame ones. Selective breeding, by contrast, is an ongoing inexorable process, and that's what happens to those tame animals afterwards. And that's the deliberate breeding or sometimes the unconscious selection by man into animals which are vast, more beautiful, more interesting or productive, just plain different.
Will - Yes, I suppose that's true because in many ways we domesticate certain animals, but we perhaps selectively breed more other animals that we don't choose to domesticate.
Katrina - You can domesticate something without actually selectively or consciously selectively breeding by enclosing the animals, by feeding the animals. So for example, foxes can be almost self domesticated to get used to being in the proximity of man without man actually actively stepping in and choosing which fox breeds with which <laugh>.
Will - With all that being said, then what would be considered the first animal that humans selectively bred?
Katrina - Dogs, without a doubt. So dogs would probably have, or wolves, the ancestor of dogs, would've probably hung around human habitations to get scraps of food and accompanied humans on hunts. Or maybe the humans accompanied dogs on hunts, and they almost self domesticated before humans actually stepped in and began actively selectively breeding them.
Will - Was the idea then that we had these wolves and wanted them to stick around, so we decided to one way or another breed them so that they're more amiable traits. The more friendly traits were the ones that stuck around.
Katrina - People like to have animals. They like to keep animals. Children adopt animal babies they pick up in the forest. They'd bring them home, they rear them. People like to be around animals. So an animal that's got an interesting marking or might have been more friendly than others may have actually been some of the first that were kept. Maybe bred after that. It's difficult to say. Certainly fast forward a few thousand years and people were actively selectively breeding animals that were keeping in their communities, ceasing that hunter-gatherer lifestyle and settling down in permanent or semi-permanent communities and actually deliberately breeding livestock for food or wool, actively speeding and cultivating plants as well. But certainly dogs came first. And how much was deliberate speeding and how much was just opportunistic, it's very hard to say.
Will - That's fascinating. I just assumed that obviously wolves had wanted to be near us and we fed them and they became more amiable. But I assumed that that was the reason why we'd selectively bred them. I didn't realise that the cosmetic value of having an interesting stripe or something like that went back so far.
Katrina - I think it's just human nature. It's still very subjective, but it probably wouldn't have been too long before people were actually at least adopting cubs and whether they were reared to maturity, it's very hard to say. It could have taken many, many years before that happened. I observed an interesting thing in a campsite in Bournemouth recently. We've got very tame foxes around here. I saw one in central London the other day. But these foxes usually have tolerance. And 've fed a fox around the corner from my home. But these in Bournemouth were incredible. I was staying at a campsite for a week, and these foxes weren't just tolerant. They were unfazed by close contact with people. It was something quite extraordinary. I'd never seen urban foxes so tame before, and it was impossible not to think about how wolves in the wild may have actually reached this stage.
Will - When did we realise what the process of selective breeding actually involved and then began to properly implement it across various species?
Katrina - I think we've been very good at this for a very, very long time. But long before we began talking about genomes, et cetera, skilled breeders have been selectively breeding and perfecting strains of animals for many, many hundreds of years. Genetics just put names to things and clarified a lot of the things which breeders knew before. Robert Bakewell was an absolute master. And he swore by the practice of what he called 'breeding in' and which we would call inbreeding. And from high school biology lessons, you remember that recessive genes, they're not actually expressed until you get the input from both parents and by breeding in and in, Bakewell was able to actually expose some of these potentially harmful traits. And there's nothing necessarily harmful about recessive genes but if they are harmful, then you don't want them in your population. But by breeding in and in, as he called it, by inbreeding, he was able to express these traits. And if he didn't want them, he would get rid of them for his population just ruthlessly cull, which was a very, very good thing. So as long as inbreeding is matched with this removal of unwanted traits or harmful traits from a population, then there's nothing intrinsically wrong with it.