If dogs are all descended from wolves..(18 Posts)
How do have so many different breeds today?
I mean, I get the basics about selective breeding etc, but how come there is so much variety when they all came from basically identical wolves?
It boggles my mind to think that my tiny chihuahua and the Great Dane down the road share the same relative ancestry.
Can someone cleverer than me explain in small sentences please?
they aren't though - they came from a common ancestor. Just like we aren't descended from apes but had a common ancestor too.
It's not explainable in one or a few sentences; read John Bradshaw's 'in defence of dogs' for greater understanding (it's an excellent read). If it helps, think of the fact that birds today descend from dinosaurs. Nature has infinite ways of evolving, it's glorious.
So did it start off as natural evolution then? And then we bred them down and down into the distinct breeds?
Ummmm. I saw something about this on tv a while ago. Something about breeding wolves with certain traits led to evolutionary changes. So. U breeding only non-human-aggressive wolves, characteristics like curly tails etc came through. So then those non agressive curly tailed dogs were bred together and other characteristics came through, then by breeding those characteristics together eventually you get specific breeds. So for example, non aggressive dogs which like to retrieve would be bred together to create retrievers. I hope that makes sense. I've hurt my brain
There was a documentary on this several years ago. Dogs have a 'slippery' gene when it comes to appearance that wolves must lack.
They also looked at how dogs interacted with humans compared to wolves. They found that if a domestic dog was confronted with a problem it would look to it's owner to help it. A tame wolf would just walk off and not look to its human.
Here is something that might help www.pbs.org/wnet/nature/dogs-that-changed-the-world-introduction/1273/
Variation within a species is crucial to its survival; however the opposite is also true, thousands of years of almost no variation is also critical, see the alligator for example.
A species will adapt over time to suit its climate and surroundings. Not all breeds of dog are from the same geospecific region, hence the variation. Of course breeding is an element to it but there are also strong evolutionary traits. Labradors, for example, hail from Canada where they were frequently exposed to harsh weather and cold water, so they have a sleek, water repellent coat, webbed feet, and a generous layer of fat, whereas sighthounds hail from what is now the Middle East so have very low body fat, and long limbs for speed to help them catch their prey quickly before succumbing to the heat.
Some breeds include jackal and other canids in their ancestry.
If you breed foxes for tameness
No other restrictions, just always pick the ones that are less scared of humans
After a few generations, they take on a lot of dog-like qualities, including floppy ears and wagging tails.
What I find interesting (and don't really understand) is that all breeds of dog are a single species. But then scientists say they've found a new species of, say, frog which they thought was an existing species but it has something slightly different so therefore it's a new species.
Is there some clever zoologist/taxonomist who can explain the difference between breed and species?
Trills, thanks for the link that was very interesting!
Regarding species with sexual isolation it's mostly down to reproductive isolation.
If they can cross and produce offspring that is fertile, then it's the same species (dogs and wolves).
If they can't cross or if the offspring is not fertile (lions and tigers, donkeys and horses) then they are two separate species.
Some species can have individuals with different morphologies.
Other different species may look exactly the same, but have different behaviours or different genomes and not be able to reproduce.
A breed is just a variant. Normally bred (selected by humans) to look different.
If you google 'dog family tree' or similar and look at the images, you can find charts that show what breeds came from what lines (and in what parts of the world). It's quite a useful visual to see how the various breeds have developed.
Just like we aren't descended from apes but had a common ancestor too.
Ahem. We ARE apes.
"Is there some clever zoologist/taxonomist who can explain the difference between breed and species?"
Not clever or either of those two things, so it's a pretty basic understanding and I could be wrong.
Breeds have the same DNA (but with different traits switched on) and the same number of chromosomes and stuff, species don't...so different breeds within a species can mate and have offspring that reproduce, different species either just can't have offspring or, occasionally can have offspring, but they're sterile.
Love that this thread was started 10 o'clock at night. Couldn't get to sleep could you love? 😂
Disclaimers <10 o'clock is MY bedtime>
<I know 'love' is not mnet, but I swear too much to join nethuns>
Because we keep dogs as pets, we can easily develop them with all kinds of traits that arise naturally through mutation, but which would not allow them to survive in the wild. A wild wolf cub born with a genetic mutation that gave it brachycephaly, for example, or no fur or abnormally short legs, would die quickly. In captivity, though, individuals with unusual traits can not only be kept alive but line-bred repeatedly to their close relatives to quickly build up a stock of animals with the desired trait.
The silver fox selective breeding experiments mentioned above only began in 1959 and show how far you can get from an original 'wild type' in just a few generations, in terms of size, coat colour/pattern, ear type, tail shape and temperament - and these foxes were ONLY selectively bred for temperament. The other colours etc just came out spontaneously, but were not eliminated by natural selection as they would have been in the wild.
The differences between species (as opposed to domestic breeds) often look much more subtle but they are much more extensive on a genetic level, being the result of (usually) a few million years of separation since the most recent common ancestor, rather than just a few hundred or thousand years. However, many closely related species can successfully interbreed. Eg the mallard has been known to produce (often fertile) hybrid young with about 60 other species of ducks and geese.
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