Middle school biology - NGSS
Artificial selection and domestication
Dogs evolved from wolves through domestication and artificial selection (breeding). Humans influenced breeding, selecting traits related to behavior and function. The process also applies to farm animals and crops, with humans selecting for desirable characteristics. Artificial selection accelerates change and shapes the world around us.
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- Why exactly do dogs look so wildly different from their wolf ancestors? In some cases the similarity is striking, such as in the case of the husky, but when we look at breeds such as chihuahuas, its hard to even imagine that they're even related to other dogs, let alone that they're descendants of wolves. It just made me wonder as to whether there were other factors that resulted in these breeds looking so different.(8 votes)
- Hi ! I would say human selection was the main factor here ;) Just like the banana you eat today looks nothing like its wild ancestors (you can google for pictures of wild bananas, and yuk, you would definitely not eat it), humans have selected and grown the mutations they liked in other organisms, and even crossed them in order to obtain something "better". And we've been doing so even before we knew anything about genes and all !(12 votes)
- how do we have German shepherds?(7 votes)
- A long time ago, people started breeding wolves with certain traits, including those that are more protective or obedient. Eventually, they also started breeding dogs with not only the traits above, but also with large bodies, short fur, large ears, and so on and so forth. I guess someone eventually wanted brown fur, and so that happened, and add a few dozen years and we have German Shepherds!(7 votes)
- How did they come to the conclusion that all dogs come from wolves? Is there actual evidence for that?(4 votes)
- Yes, there is genetic evidence as well as fossil and historical evidence.(11 votes)
- how are dog related to wolfs(1 vote)
- Dogs and wolfs have a common ancestor that lived about 130,000 years ago.(1 vote)
- He states what rottweilers, border collies and terriers are good at but not what the chihuahua is good at. Does that mean chihuahua's are useless 🤔🤔🤔(⊙o⊙)(1 vote)
- One of the theories is that chihuahuas were originally bred by pre-Columbian Mesoamerican peoples as companion dogs, or dogs specifically meant to be pets.(0 votes)
- does anyone listen to future?(0 votes)
- [Instructor] Most of us are familiar with dogs, often times 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 species 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 and 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 have been specialized to maybe 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. Artificial 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 looked like this, that looked like a wolf, that were a wolf. And what we theorize is that the early stages of some wolf 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 left over food here or there, and some of the wolves that just happened 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 left over food, being able to get some of the remains that the human beings left behind. But then over time, human beings probably realized that hey, these wolves are useful to have around. Maybe 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 allowed 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 dogs 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 look like that. And once again, they would have selected for things like docility, 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, but over roughly 10 or 15,000 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.