Should We Just Call Dog Breeds a Different Species? 497
Jamie found an amusing bit this morning on Scientific American where the author proposes that dog breeds are different species. Now some of you might recoil when you hear this suggestion, but if you read the article to see why he makes this suggestion I suspect you'll crack a smile and appreciate the elegance of the solution.
Starting a war (Score:0, Informative)
Definite proof that cats are better than dogs.
Biologists already use his criteria. (Score:5, Informative)
Re:I always thought the difference (Score:3, Informative)
http://en.wikipedia.org/wiki/Ring_species [wikipedia.org]
Re:Biologists already use his criteria. (Score:4, Informative)
Defining species based on whether animals can breed is not a perfect definition. Fin and Blue whales have been known to breed, to form hybrid species, for example.
And not entirely correct (Score:5, Informative)
When we observe Ring Species we are clearly catching mother nature red-handed in the act of speciation.
http://en.wikipedia.org/wiki/Ring_species [wikipedia.org]
These things are freaky:
A--B--C--D--E--F--G--A
Members of a ring species can interbreed with their immediate neighbors, but not with distant neighbors halfway around the ring. (So in my diagrom, A can interbreed with B and G, but not C, D, E, or F. Sometimes the ring develops a break, and becomes a line:
A--B--C--D--E--F--G
Then to have a speciation event, all you need is another break in the line:
A--B--C
E--F--G
There are ring species comprised of small creatures who only live in a small range of elevation around the side of a mountain, so their habitat literally looks like a small ring. Two well timed avalanches could be enough.
Re:Dogism (Score:3, Informative)
Nah! they are just desperate for sex...
Re:Dogism (Score:3, Informative)
Only when the population pool is extremely small. I.E. within the same family (inbreeding). From what I understand, remarkably small population pools maintain genetic diversity very well. It's definitely sub-50 members, and I think it is actually in the teens but I'm too lazy to look it up.
Basically, following the "second cousin" rule is about as big a pool as you need to preserve genetic diversity.
I suspect the problem with Cheetahs may be the individual families are too spread out, and they don't intermingle, causing several generations of inbreeding. However, it can be restored with the introduction of just a few new lines.
Re:Starting a war (Score:2, Informative)
I think you do not understand who is the "pet" in a human - cat relationship.
Re:Dogism (Score:4, Informative)
http://en.wikipedia.org/wiki/Tame_Silver_Fox [wikipedia.org]
It is a very interesting project, actually. It only took 19 generations to produce a fox with behavioral traits roughly approximating those of a common domestic dog.
Re:Dogism (Score:2, Informative)
Generally, our diets are more conducive to growing taller than our parents diets were (proteins, calcium, etc).
Generally, we think young people look better.
Re:Dogism (Score:3, Informative)
That's not really racism as much as territorial and tribalism. You have to introduce new birds slowly and occupy the time of the more aggressive birds so that they notice the others but don't bother themselves with them for a while. eventually, they will forget about it.
Roosters are the males protecting the flock. That's why they are valuable even if your just raising layers. Your uncles scenario is more about pecking order and a threat to that order then anything racial or species related.
Re:Dogism (Score:4, Informative)
Dogs and cats do, yes. I don't have any frame of reference outside those species, but I imagine that they would, as well... from what I do know, though, mixed breed dogs/cats typically have stronger immune systems and are less prone to some of the other genetic problems that plague purebreeds.
As a case in point... my dog is a cross... we're not entirely sure what her parentage is, but she bears a striking resemblance to a Harrier Hound. She's not pure, though... she's got some traits from an American Foxhound, and frequently gets mistaken for a Beagle... she's got about the same markings, but is bigger and taller. You can't really tell, though, unless you know the breeds, or you see her standing next to a Beagle (at which point you notice that she's about twice the size of one). All we know for sure, though, is that she's a cross-breed.
The thing is, dogs in that family of breeds have a tendency to develop hip dysplasia ( http://en.wikipedia.org/wiki/Hip_dysplasia_(canine) [wikipedia.org] ). In spite of that, my dog has no signs of developing it. In fact, I don't think I've ever seen her get sick.
Likewise, among house cats, there's a pronounced difference in the immune systems of cats who are cross-bred. It's hard to tell among cats, because most of them are cross-bred by now anyway, but pure-bred animals rarely live to the ripe old age of 20... by contrast, the only cat I ever had in my life who didn't live to that age was a tabby, who developped stomach cancer at 14. Even 14, though, is very old for some purebred cats.
So yes. With my limited experience, I'd say that animals do experience "hybrid vigor". And probably for the same reason that plants experience it... they're a new biochemistry, new immune system, and the viruses and harmful bacteria* aren't adapted to it.
* I say harmful bacteria, because as we all know, there's good bacteria, too. I read somewhere, but I can't remember where, that there's actually more bacteria cells than human cells in the average person....
Re:Dogism (Score:2, Informative)
The concept you're referring to is hybrid vigor:
http://en.wikipedia.org/wiki/Heterosis [wikipedia.org]
Re:Dogism (Score:2, Informative)
As you're in the UK, that's easier said than done. Wolf fur comes under CITIES legislation, which means it's technically illegal to send any without both parties owning CITIES certificates. Our wolves are registered under CITIES, but when I got some fur sent to me over a decade ago they weren't.
Anyway, I'll see if anything can be done!