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Video transcript

most of us are familiar with dogs oftentimes known as man's best friend and what's fascinating about them is that they are one species even though different types of dogs different breeds could look very very different and the fact that they're one specie says that if you have a male and a female dog any two that in theory they could reproduce and produce viable offspring although in for example the case of this character in this character the mechanics could get quite difficult but an interesting question is is where do dogs come from and why do we have these seemingly specialized breeds amongst dogs you might have things like a Rottweiler that's better for protection you might have things like Terriers that would have been specialized to maybe we go after rodents you have things like Border Collies that are good at herding other types of animals the simple answer is through artificial selection and domestication remember in any population of a species there's variation in that species and when we talked about natural selection that's where the environment might select for certain of those variants certain of those variants might make it a little bit easier to survive or reproduce and then those would predominate and that's how evolution happens our official selection and domestication is where humans take matters into their own hands and instead of waiting for nature to do things they are the selection factor they pick which of the species get to reproduce and which ones don't and when you have that type of artificial selection the change can happen much much faster breeding is essentially artificial selection so dogs like this and all the dogs we know of had ancestors that look like this that looked like a wolf that were a wolf and what we theorize is that the early stages of some Wolf's eventually evolving into dogs might have been more traditional natural selection where tens of thousands of years ago our hunter-gatherer ancestors as they hunted and gathering they might have leftover food here there and some of the wolves that just happen to be the variants that were a little bit more comfortable getting close to humans might have benefited from being able to get some of that leftover food being able to get some of that the remains that the human beings left behind but then over time human beings probably realize that hey these wolves are useful to have around maybe they're they provide some form of protection maybe over time they started breeding the wolves so the wolves that were especially friendly the wolves that were especially good at a certain task say protection or going after some type of an animal or retrieving things they allow those to reproduce together and over time over tens of thousands of years we went from wolves to dogs and even once we had dogs the breeding got even more specialized as I mentioned things like Border Collies this was many years many generations of breeding where sheep herders might have selected dogs that were good at herding sheep that Terriers came from dogs that were good at going after rodents things like Rottweilers or dog's breeding the dogs that were especially good at providing protection or defense and it isn't just dogs that are products of artificial selection and domestication pretty much any animal that you might see on say a farm would be the product of artificial selection and domestication a wild pig looks like this while the ones that you would see on a farm looked like that and once again they would have selected for things like facility things where they're less aggressive and they're easier to take care of and artificial selection and domestication does not apply just to animals pretty much anything you might see in the produce section of your supermarket is the product of artificial selection and domestication there might be wild variants of these different vegetables or these different fruits over roughly ten or fifteen thousand years of human agriculture every generation of crop they would have selected for the crops that are more robust that tasted better that were able to grow in different climates and by allowing those variants to reproduce we eventually ended up with the domesticated crops we see today
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