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.
Dogs are not a species (Score:2, Interesting)
Dogs aren't even a separate species from wolves. Further subdividing them is just silly.
No, but... (Score:4, Interesting)
Re:I always thought the difference (Score:3, Interesting)
consider: 'species' A can breed with 'species' B, so are the same species, B can breed with C, so are the same species, so A and C are the same species via B, although A and C may not actually be able to breed. im fairly sure examples exist, but i cant cite any off the top of my head
Comment removed (Score:4, Interesting)
Re:Dogism (Score:4, Interesting)
While I see what you're trying to say, you neglect to point out that dogs have a hierarchy just like any other social group. Yeah, it sucks and humans should be above that but it's there with the dogs you use as an example.
Re:So what we're saying is... (Score:2, Interesting)
People that don't want to believe in evolution are hopeless anyway. What this does is move the discussion away from the details of biological classification towards facts that are more interesting when discussing evolution.
The fact that we are rather different creatures from mice is notable, but a discussion of evolution doesn't depend on the factors we choose to use to make the distinction, it works just as well to consider organisms and populations that are or are not capable of reproducing without ascribing any further meaning to that fact.
Re:Dogism (Score:5, Interesting)
Birds are racist. Conure flocks will exclude similar animals whose only real difference is a different-colored head.
Re:Dogism (Score:5, Interesting)
Social hierarchies in animals are just as dysfunctional as they are in humans. I saw some documentary where one of the younger dominant females kept taking food out of the mouth of one of the subordinates ones. It wasn't that she was particularly hungry because she got priority access to the best food. As far as anyone could tell she was doing because her status let her get away with it.
Humans (Score:3, Interesting)
The author mentions that the varying dog breeds would be thought of as separate species if found in the fossil record, and that's probably true. There are paleontologists who argue about whether a certain small T. Rex fossil is a dwarf species or a juvenile. The hairs to be split can be quite thin.
Given that, would the morphological differences between human populations constitute splitting Home Sapiens into separate species? I think not.
The only thing this proposal will do is give the creationist/ID idiots another straw man argument: "scientists change things to justify their point of view!" The truth is, those morons are going to cling to their dogma not matter how much evidence piles up against it. We've seen it before: the Earth is flat; the Sun revolves around the Earth; Earth is 6000 years old; et cetera.
Speciation is such a slow process that we can only see it in the simplest of organisms, such as algae or bacteria. But that's not good enough for them. They apparently want to see two chimps mate and produce a human (which is absurd), and proves that they refuse to understand the subject matter.
Re:Dogism (Score:5, Interesting)
What's even funnier is that dogs know wolves.
I'm lucky enough to volunteer at a wolf centre in southern England. At this time of year they're moulting like crazy and it's easy to pull of clumps of underfur from them.
The fun starts if you give some to a dog owner and ask them to show it to their dogs.
The last time I did that it made my friend's 4 dogs go nuts - one went very wide-eyed, another tried clambering over the guy to get it and the third begged for some. I've seen other reactions including frenzied barking and fear from other dogs.
So it seems that despite most dogs never getting to see a wolf (at least here in the UK, we shot our last wolf in the late 1700s), they still know full well what one is.
As an aside, dogs are amazingly different from wolves despite being 99.8% the same DNA wise. Only one season a year and permanent puppyhood - domestic dogs don't become adults, we've bred that out of them somehow. Wolves, on the other hand, change noticeably around 3 years of age. Dogs are also much, much better at picking up signals from people - and unlike wolves, they're always eager to please if bought up properly. A wolf'll only do something if it feels like it, or if it'll get something out of it!
And an amusing anecdote to finish - we used to take our wolves out to county shows, as they're socialied and enjoyed meeting people. One morning at the Kent show we let the wolves into their mobile enclosure and they watched intently as some Rottweilers came over, along with their (big-mouthed) owners. The blokes were going on about how their dogs could "have" our wolves easily, yet both dogs cowered away when Duma, one of our soppier wolves with people, casually gazed at them, raised her lip soundlessly, showing impressive fangs. Those Rottweilers knew better than to come any closer, much to the chagrin of their owners!
Re:Dogism (Score:3, Interesting)
Several animals, mostly humans have a natural repulsion to different looks. The scientific explanation is it is our avoidance to disease be it mutation or infection. I think younger generations have had enough cultural exposure to the different human races that we don't instinctively think of them as mutations, but someone who has had no exposure when young probably has a strong instinctive response. I wonder why dogs don't?..
Re:Dogism (Score:5, Interesting)
I've no proof whatsoever, but to me it seems to happen in humans. When I think of people I know, the ones with diverse ethnic backgrounds are invariably taller than either of their parents and very often good-looking. Presumably this is because something like height is coded for on many different parts of the genome. And so if your father's small because of recessive gene a, and your mother's small because of recessive gene z, and you get a dominant A from your mother and a dominant Z from your father, then that's two fewer genes putting a ceiling on your height.
Yes, I know this is trivialising an incredibly complicated issue, so hopefully somebody with more of a clue than me can weigh in with the knowledge here.
Species are being created all around us. Right now (Score:4, Interesting)
Of course this guy is just poking fun at creationists, but mislabelling dogs as species would really help. For that matter it wouldn't help if they really were separate species.
1) Dog breeds may be a recent thing but nobody say them evolve either - it happended over a time longer than a human lifetime. If you're of a mind to deny these things then "I didn't see it with my own eyes" argument applies just as well here. Maybe God created Chihuahas and Great Danes. I slighty smarter creationist might complain that the selection pressure on most breeds was artificial.
2) Much more to the point, there are genuine species all around us at every conceivable stage of speciation. Heading towards branching, during branching, immediately after branching, long after branching, etc.
The best answer to a creationist who says "if it's true, why don't we see it?" is to ask "what is it you'd expect to see that isn't in fact all around you right now?!!". Anyone expecting to see Tigers bifuracte into furbys and unicorns in their own lifetime isn't worth trying to argue with, but anyone who realizes the timescale of evolution should realize that's not the case. The length of a human lifetime is so ridiculously short compared to the evolutionary timescales that we're essentially looking at snapshot of a movie.
Think of it this way: earth is 4.5 x 10^9 years old. If you had a feature length 2 hr movie of the whole of earth's history shot at 60 frames per second, then the movie would have 432,000 frames, and each frame would still encompass over 10,000 years of history! (4.5 billion / 432,000). And yet these creationists are expecting to see a whole movie playing in their 100 year lifetime...
So, realizing that our brief lifetime has doomed us to only be observing a snapshot of anything happening on an evolutionary timescale, the real question isn't why arn't we seeing it happen (trivial answer: your lifetime is too short, but rather if this is the movie of evolution we're caught in a still frame of, then what would you expect to see in this still frame? The answer of course is that you'd expect to see species caught at every stage of branching/speciation, which is exactly what we do see.
1) Species accumulating genetic change, living in subpolulations, apparently heading for branching: too many to list, but including things like forest/plains elephants, dogs(!), humans (assuming the races don't in the future start interbreeding indiscriminately). Even things like lions/tigers can still interbreed so (whatever arbitrary labels you want to slap on them) are really pre-branch rather than post-branch, even if we understand the amount of interbreeding in the wild to be close to zero (although it does occur).
2) Species that are essentially at the point of branching right now. A classic example might be horses/donkeys, which can still kind of interbreed, but not quite (their offspring, a mule, is sterile). Given that branching is more of a process than event (it's something that happens to populations, not individuals) there are many more less spectacular examples - I'd probably include some of those (technically) pre-brancing examples in this class.
3) Species that are post-branch (can no longer interbreed, but are still genetically very close) : any species withing the same biological genus, familiy, etc. One's that branched more long ago are more genetically different corresponding to biological order, class, etc. For a specific example, how about oursellves and chimps still with 98% shared DNA and only a few million years after having branched from a common ancestor.
So the still frame we're living in sure fits the bill - we see everying around us that we'd expect to see if species are created by branching from each other. OTOH if the creationists are right, and species are created by God then the number of species that exist along every conceivable degree of genetic difference (as opposed to isolated individual creations) is rather embarassing!
Of course these discussions are endl
Re:Dogism (Score:5, Interesting)
In fact you have it correctly; human brains are physically oriented towards sight while a dog's is oriented towards smell. They also have an organ for the detection of sex pheromones. Their ability to focus is less developed than ours, though they have far superior night vision. They have much less depth perception than humans due to the position of their eyes, but have much a much more directional sense of smell due to the design of their nose.
Re:I always thought the difference (Score:3, Interesting)
This criterion works only with livings which actually interbreed. It won't work for parthenogenetic livings or for livings like bacteria.
And even within sexual species it is problematic. Take dandelion (yes, this yellow flower) for example.
According to your definition of a species there are hundreds of thousands of species within the "dandelion" (taraxacum) genus.
Dandelion comes in three general types: A diploid one (with two sets of chromosoms), a triploid (with three sets of chromosoms) and a tetraploid one (four sets). If two diploid plants interbred, they have tetraploid offspring. If a tetraploid plant interbreeds with a diploid plant, they have triploid offspring. Triploid plants are infertile, they don't interbreed. Instead they generate triploid clones of themselves. Sometimes the number of chromosome sets is reduced to two in that process, generating diploid offspring, which then can interbreed with tetraploid and diploid plants. So the generation cycle is closed.
All three formes exist in the same biotope. All three look the same. Dandelion is pretty adaptive with this generation cycle: You have diploid forms which remix genetic traits. You have tetraploid forms which help generating triploid forms, and you have the triploids, whose mutations are spread wide. If some of those mutations manage to survive for enough generations, they generate fertile forms for remix of the genetic pool.
According to your definition each individual plant of triploid dandelion and his identical clones are a separate species, because they don't interbreed with any other dandelion. Also the tetraploid forms are separate species, because they don't generate fertile offspring. Only the diploid forms are able to generate fertile offspring at all!
TFA is far too bold (Score:4, Interesting)
The dirty little secret of biology - and I'm going to get kicked out of the biologist club for this - is that we've got no ****ing clue what a species is. Oh, sure, we go around naming them all the time, but we don't actually know what we're doing yet. One list counts up to 23 different way to recognize species (known as species concepts). Some of these are mutually exclusive! The author seems to like the Reproductive isolation species concept. But under that concept, the mallard on the east coast is a different species from the mallard on the west coast. But when does the mallard cease to be east and west? What about all those ducks in between? While there's no doubt that the east coast and west coast are functionally isolated, the point at which that ceases to be is very hazy.
What about montane species? I'm thinking of Dall sheep, in particular. Geneflow (interbreeding) between sheep of non-ajoining mountain ranges is incredibly low, effectively zero. But I don't know anyone who'd make the argument that they're separate species.
So then maybe the author wants to argue that they're separate morphotypes, and should be species on that account. What about isopods, where they have a greater diversity of form within species. Let's face it, every dog looks vaguely dog-ish. The same can't be said for some isopods, or species of insects!
The truth is what is, and isn't, a species is currently nebulous, fuzzy, and wishy-washy. It may be that species, as an idea, don't exist. That wouldn't surprise me.
Re:Dogism (Score:3, Interesting)
I saw a great segment on I think Discovery Channel about wolves vs dogs.
First, a piece of meat was tied to a length of rope and placed in a cage. Both the dog and the wolf ( on the outside of the cage, of course) were able to pull the meat out using the length of the rope.
Next, a piece of meat was tied to the rope, but the rope was then tied to the center of the cage, so no matter how hard the rope was pulled the meat would not move.
After a few tugs the dog ran over to the humans and looked to them for help. The wolf spent longer tugging on the rope, but eventually gave up and walk away, not even acknowledging the humans standing nearby.
Re:Dogism (Score:4, Interesting)
In any case, these groupings are more than skin deep; it is cultural similarities that tie them together more than the color of their skin, in many cases the culture being a preexisting condition through generations of gang hierarchy that extends from the streets to the prisons and vice-versa. Racial grouping in prisons is much more complex than simply being visually identified as a member of a race, though I'll grant the moot point that color is the most obvious indicator of the index of cultural, historical, and socio-economic similarities.
Re:Trolls (Score:3, Interesting)
Perhaps serious scientists should stick with doing science, rather than refuting creationists and others with ideological agendas to push. Cause when you feed the trolls, the word gets around and you draw larger and larger numbers to be fed.
That's an interesting strategy.
What if the trolls can do other things besides just make noise? What if they can get on your (future?) kids' school board and decide that your kids should be taught intelligent design and/or creationism as science?
Do you think it's a good education? Do you think it's a good way to spend tax money? Do you want your kids' time spent on this?
I think you're getting too used to Internet trolls and have forgotten how real-world trolls can make changes to society that you do not want.
Here's a recommendation: listen to The Skeptics' Guide to the Universe. It's a great podcast, done by science nerds, about science and all the kooky beliefs that are at odds with science (creationism, alternative medicine, ESP, a broad grab-bag of topics, all entertaining). They will argue (much better than me) why considering what the trolls can do is important.
Re:Dogism (Score:4, Interesting)
So he didn't have any problem with little guys, but there was this one little terrier on our morning walk that was very loud and aggressive. Normally my dog takes the attitude that these kind of yappy dogs are just insane and should be avoided. The terrier bit my dog a couple of different days - the second time on the end of the nose; his owner never had him on a leash or attempted to control him and seemed to think this was funny. This was stupid of both the owner and the dog - mine could have almost swallowed this thing in two bites - he could certainly have killed him with one bite. The third time the terrier tried it my dog just put his jaws around him and pushed him onto the ground and gave a gentle squeeze. The guy didn't think it was so funny anymore but his dog stopped being aggressive - guess he was smarter than his owner.