This story in the Times of London (breathlessly titled "How man's best friend overcame laws of natural evolution"*) has been linked to by Dembski over at his blog and by a number of other creationists around the web. I guess they think it somehow disproves evolution or problematizes natural selection. It discusses an article in Genome Research which used mtDNA analysis to examine selection in dogs and wolves and notes (according to the article) that natural selction
was relaxed when dogs became domesticated. Living with people allowed harmful genetic variations to flourish that would never have survived in the wild.
Folks, there are no surprises here. We've known for years that domesticates come under relaxed natural selection. Indeed, some of my own work on cranial variation in domesticated carnivores and feral domesticates has examined the interations between selection (natural, artificial & sexual) and domestication. We also know that domesticates come under much stronger prolonged selection than natural populations. This selection for a given trait often leads to other traits that would be deleterious in the wild but that are not selected out in anthropogenic environments. None of this is new as far as I can tell, and certainly those of us working in morphology have known this for years.
The article quotes Matthew Webster, one of the researchers:
We found that dogs are accumulating mutations in these genes at a significantly faster rate than wolves. Rather than being beneficial, most of the additional mutations are likely to be slightly harmful. We suggest that it is life alongside humans that allowed these mutations to remain in the dog population.
Living with humans means harmful mutations can still survive in dogs that wouldn't have been able to breed in the wild. Wolves, which have to hunt for food, compete for mates and sleep without shelter, would be less likely to survive if they had these mutations," he said.
It is possible that changes in lifestyle caused by dog domestication have allowed mutations to accumulate across the entire dog genome, contributing to the huge differences in appearance in today's dogs. This could also explain why so many diseases affect modern breeds, a consequence of the weaker natural selection. A lot of dog breeds now wouldn't survive if they weren't living with humans.
Again, I'm somewhat underwhelmed. I can only see this paper as perhaps demonstrating, using new-fangled genetic thinga-ma-bobs, some ideas that we old-fashioned morphologists have known for awhile: i.e. that domestication relaxes natural selection and increases the raw material for artificial selection.** Certainly, there's nothing here that invalidates anything in modern evolutionary theory, and perhaps a perusal of Darwin's own Variation of Animals and Plants Under Domestication (1868) would be beneficial for geneticists, reporters, and Dembski.
--
* I'm not sure what "Man's best friend [overcoming] the laws of natural evolution" even means. It's worth noting that the standard of journalism exhibited by the author, Jan Battles, is fairly poor - Darwin's 1859 work is referred to as Origin of the Species. Argh!
** There might be more to this study - though you wouldn't know it from the Times article. The paper isn't available online, so I reserve the right to change my opinion when I actually get to read it.
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Natural selection isn't an ogre or thing right? It is what we call a vast set of processes that lead to the survival of certain populations and the extintion of others. So in this case we too become a part of 'natural selection' inventory by helping along certain populations that others might not. Aren't certain parasite colonies or symbionts similarly helped along as we help purebreds along?
As usual BillD misses the obvious
The real weirdness here is that the authors seem to assume that terms like "beneficial alleles" and "detrimental alleles" have intrinsic meaning apart from the selection being applied.
Sure, short dachshund legs might not be beneficial in the wild (more correctly, the modern wild -- I suspect that critters can get away with a lot more in a depauperate post-mass-extinction fauna), but everyone knew that already.
Heck, wings can be "beneficial" or "detrimental", depending on the environment. Birds on predator free islands have repeatedly lost the ability to fly, and in the case of kiwis have basically lost the limbs altogether.
I hear you John. What changes is the selection pressure itself.
A newly domesticated animal or plant that lacks the trait we're selecting for is ruthlessly weeded out, while traits that previously would have given an advantage or disadvantage in a wild setting are largely a moot point (provided their not catastrophic).
Take for example many of our domesticated crops. We selected wheat whose seeds did not shatter off the stalks and almonds that lacked cyanide (both traits the cause of simple mutations). This was undoubtedly a death sentence by natural selection for both plants -- but a windfall once humans decided they wanted those features.
As far as genetic diseases affecting modern breeds - I would strongly imagine there's been a wee bit of a bottleneck as these organisms have undergone human selection.
German Sheperd breed suffers from hereditary hip displasia
Dalmatians suffers from hereditary deafness
That's from the top of my head, and I'm not a dog persob
Those diseases would probably get culled quickly in the wild.
The ToE accounts fully accounts for, and even predicted those genetic weaknesses.
What does ID tells us on Animal Domestication ? Nothing.
That's right Nick. Some of us kiwis had to use artificial wings to get where we are.
I think we can all see where the following comment over at UD is going:
Well, it points out here that science places an absolute upper bound of 60,000-90,000 years on the most recent human ancestor, since that's when "Y-chromosomal Adam" lived; and non-genetic simulations by one group indicated that, given known facts about historical human migrations, it's possible all of today's humanity could date from a group of ancestors as recent as 5000-15000 years ago.
But somehow I don't think that's what the UD commenter was referring to.
Dogs and other domestic animals raise some interesting questions about design. It is pretty clear that people designed the Pekinese for their own purposes using artificial selection. So did the original designer have the Pekinese in mind anticipating what we would do? Or did we subvert the plan? Or did the designer not have any particular species in mind - just sort of wound the whole thing up and sat back to see what would develop? But,then that looks remarkablely like evolution by natural selection.
...say the exact same people who find it absurd that chimps and humans could have diverged from a common ancestor in 5-7 million years. Unbelievable.
Nick wrote: The real weirdness here is that the authors seem to assume that terms like "beneficial alleles" and "detrimental alleles" have intrinsic meaning apart from the selection being applied.
This is a common misconception among beginning biology students. It's one of the toughest to address, but once it's remedied, the lights usually go on.
Of course, when someone claiming to be an expert has the same misconception -- well, nothing can be said that hasn't been said already.
Those guys need to get to the library more often and do a bit of reading.
"How man's best friend overcame laws of natural evolution"
I think it's just the legal aspect that appeals to Dembski. His side has fared very poorly in the courts, you know; so it is intriguing to him to read about any "law" being overcome.
Sure, those little fluffy, stupid as a brick dogs would end up as food tremendously quickly in nature. But they aren't in nature now. They are in the homes of humans, and the important trait is cuteness and loveability, so the stupider and fluffier you are, the more likely you are to produce offspring. It is exactly the same as natural selection, except the selective pressures are applied by human desires, not by nature.
Is Dembski really that dumb, or is he just preaching desperate nonsense at his followers?
Yes.
What I got from the newspaper article (haven't read the paper it cites) is that the question is not that domestication relaxes natural selection, (of course it does) but how do we explain the (apparent) breadth of diversity in dogs given the relatively short time since domestication? Are there any other domesticated animals that have anywhere near the range of morphologies that dogs have? For example, I don't think that cats show a similar range of phenotypes. Is that because cats have not been domesticated as long, or have not been under disruptive selection, or is there something different about their genome?
Is there something special about canids, or would any animal diverge into so many types given similar artificial selection pressures?
Pigeons.
I also fail to see how this is anything other than the expected result. I would also expect that human beings, thanks to agriculture and modern medicine, are likewise accumulating such mutations as NS is relaxed. Take those away, and we'd be winnowed down by that merciless mechanism lickity split.
What everybody tends to overlook is that the domestication of dogs effectively demonstrates the power of random mutation. Sure, a Chihuahua and a St. Bernard are both "just" dogs (although if those were the only two breeds, I have to wonder if they would both be classified as the same species)... but at the same time, neither is a wolf. And the huge range of morphological and genetic variation demonstrated by domestic dogs--especially by extremes such as chihuahuas and toy poodles, which are about as unwolflike as you can get--may have been artificially selected but this variation had its origin ENTIRELY in random mutation (unless the ID folks want to propose that our prehistoric ancestors were somehow capable of inducing genetic mutation in the wolves they domesticated).
The funny thing about that "15000 year -> 6000 year" quote is that the author accepts the 15000 year figure, but then totally negates it by using the creationist 6000 year limit. So how long have humans been here? 15000? 6000?
The other point is that this guy probably believes in a flood some thousands of years ago which would have reset the total number of dog breeds to 1, which this paper completely refutes.
i think king aardvark is making the important point here. dogs can't escape the laws of natural selection. the laws of natural selection cannot be relaxed. dogs were just placed in a different environment than that which they previously inhabited, and now have evolved to fit it.
i'd say they fit very well. will great danes disappear because a large portion of them have debilitating (in old age) joint problems? not as long as we like big dogs. will incredibly ready-to-eat toy poodles ever be extinct? not until humans are... but i don't see why we should consider our own decision-making ability as somehow separate from other environmental pressures that affect selection. we like companionship and cute things because they help us maintain social groups and protect our children. these are advantages we acquired through evolution. they are also the reasons we keep dogs.
we are part of the environment in which we live, and domestic dogs live in the same environment as us. they have evolved to exploit us. i don't think we ("we" being all living things) can escape the laws of evolution any more than we can escape the laws of physics.
I did see the post on UD last night, and wondered why they were putting in an article that sensibly backs up natural selection.
I suppose it's like others are saying, though, that somehow it's supposed to call NS into question, apparently because NS isn't acting like a "law" that operates the same regardless of circumstances. Or perhaps because Dembski is unwilling to stoop to the pathetic level of detail that explains the differences.
Otherwise it just seems to be the usual thing, pick a phenomenon that scientists have discovered, and try to spin it to be in favor of ID. Dembski's not even trying very hard any more, though of course it also didn't take much effort to claim a complexity that has never been produced by any observed intelligent designers as the result of "intelligent design".
Wasn't the earth and life on it created by fiat? Then why not claim evidence for ID by an analogous fiat, not bothering with science's pathetic level of detail? It's, well, a creative act, something that science just never quite appreciates as science.
Glen D
http://tinyurl.com/b8ykm
And Wamba? Cabbages and their kin:
Cabbage (Brassica spp.) have been cultivated in Eurasia since ancient times. Pliny the Elder (23-79 A.D.) claimed that the Roman people had used cabbage for food and medicine at least 600 years before his time. By that time there were already 'curly' and 'smooth' leaved varieties of cabbage (Pliny (79), 1991). Today, the number of varieties is greater, and some of the cultivars are extremely different in appearance. It comes as a surprise to most school children to learn that Brussels sprouts, broccoli, kale and kohlrabi are the same species!
Of course humans have undergone many thousands of years of relaxed selection as well. That doesn't mean that they are no longer subject to the laws of natural selection. It just means that, as long as we have modern technology, deleterious alleles will continue to accumulate in the human gene pool. If we lose modern technology due to some unforseen circumstance, (or more likely due to something we definately should have seen coming and prepared for but didn't), we could be in real trouble. Of course, under those circumstances, feral wolves will probably do much better than domesticated dog breeds. Why some people cannot understand that the environment can change is beyond me. Of course then I guess they would have to admit that the old "there are no beneficial mutations" nonsense is meaningless. What is beneficial depends on the environment. So if the environment can change, it is nearly impossible for some variation not to be beneficial at some time.
"And the huge range of morphological and genetic variation demonstrated by domestic dogs--especially by extremes such as chihuahuas and toy poodles, which are about as unwolflike as you can get--may have been artificially selected but this variation had its origin ENTIRELY in random mutation (unless the ID folks want to propose that our prehistoric ancestors were somehow capable of inducing genetic mutation in the wolves they domesticated)."
I think we Evilutionist Darwiniacs actually contribute more to the ID "theory" : P than the IDists do...
"Are there any other domesticated animals that have anywhere near the range of morphologies that dogs have?"
Similar experiments have been done with domesticating dogs using the 'base' species of gray fox. I had some good links to related articles, but my google skills are lacking today.
This experiment has been ongoing for about 60 years now. The only thing the breeders select for are the fox's affinity to humans, it's 'domesticity', if you will. The amazing result is that they started seeing foxes with floppy ears, variegated coats, curly tails....many of the traits we associate with domestic dogs.
And the point about pigeons is a good one too, and one the C Darwin wrote about extensively. :-)
Cheers.
Let me see if I have this right, Mr. D. Dogs exhibit the high degree of trait diversity that most species do, thanks to random mutations, and the cleansing effect of nature selecting out all but the reasonably good sets of traits.
Then man comes along and begins to dominate the natural selection process by applying his own narrowly defined breeding criteria to dogs.
As a result, man gets what he is looking for, but since he dominates the selection process and ignores a lot of defects, the breeds end up with undesireable traits, such as lupus, deafness, blindness, hip displasia, etc.
Isn't this the perfect experiment to demonstrate evolution? If this isn't already in the school textbooks, shouldnt it be in there as a dramatic teaching tool?
Also, isnt this notion some 100 years old? What's with this guy? Hey, I am not a biologist. Help me out here. Is it me or is he losing his mind?
Seems to me that Dembski's original "mission" was to mathematically disprove even the possibility of natural evolution. Having miserably failed on scientific terms, and since Dover failing on political/PR terms, the content on UD has devolved into:
(1) the same old straw-grasping "problems" with evolution that creationists have been using for over a century,
(2) social/religious/political issues having nothing to do with science (look at DaveScot's proud display of the Semper Fi ballcap as just one example), and
(3) pathetic ad hominem against biologists (Ma & Pa Kettle doing math).
BTW note that Dembski canned DaveScot in favor of Denyse O'Leary. Oops, I mean DaveScot resigned.
Well, of course, WAD got it wrong. It's easy to google "overcame natural laws". It takes a bit of effort to read the paper, though.
That's okay, all he needs is the title; it makes a good soundbite or name-drop.
That article is actually a *vindication* of evolution. It just shows how some biologists puzzling over the high rate of evolution in domesticate dogs realized that this is due to the fact that domestication allows for faster survivable mutation rates since the selection pressures are different and generally lower. Duh!
Just when it seems that Dembski might be capable of something resembling sanity, or at least non-flakiness, he jumps on something like this. How does he expect us to take him seriously when he makes it this clear that he doesn't even understand popular science stories in the newspapers.
I strongly suspect that Dembski sees breeding as an example of what he calls assisted search (see "Searching Large Spaces" at designinference.com). The breeder begins with a given evolutionary "search procedure" and breeding stock, defines a goal of obtaining certain properties in individuals, and then assists the procedure in achieving the goal by intervening in the evaluation of reproductive fitness. Dembski contends that only intelligent assistance can speed emergence of the target properties. He also says that intelligence cannot result from chance-and-necessity natural processes.
Dembski may see the article as validation of his assisted search model, which he says applies more generally to evolution. Many who have posted here have played into that interpretation by writing of breeding as unnatural. If you believe that human intelligence defies explanation in terms of matter, energy, and their interactions, then so be it. But if you believe, as I do, that intelligence is best explained as emergent properties of the material brain, then please take care to speak of humans and their activities as natural.
In the reports I have seen on the gray fox experiments, the other traits that appeared were explained as a result of neoteny. Immature features were carried on into the adults.
"The animals are also cuter than wild foxes in that they have rounder muzzles, large eyes, and proportionally shorter limbs. "
from:
http://sciam-editor.typepad.com/weblog1/2005/02/sly_fox_tame_fo.html
It is not clear from the abstract just how novel the conclusions of the Swedish study will prove to be. On the other hand, their complete mitochondrial sequencing results alone should garner citations.
I have it in mind that I once read that the plasticity of the canine genome could be a result of neoteny. Memory and Google fail me.
Saying that natural selection "relaxes" when dogs come under domestication is absurd. We are part of the natural environment, dogs are way more successful than wolves. In an environment where humans dominate, cuteness counts more then teeth. It is all part of the natural world and evolution. To say that they are somehow genetically deficient because they would not do better in another, fast dwindling environment is purely hypothetical.
"So did the original designer have the Pekinese in mind anticipating what we would do? Or did we subvert the plan?"
I think you are taking a too human-centric view of our interaction with dogs. Sure we breed dogs for certain characterisitcs, but we do so because we in turn are suseptible to these characteristics. In other words we are both just living expressing our genes and interacting. Think how many people like dogs - it may be that people that liked dogs were more successful (better hunters) than those who didn't, so maybe dogs have been breeding us to be dog lovers. It is just an interaction, the fact that we may be a little more consious of what is going on than the dog is irrelevant.
Sure, morphologists have been throwing bones forever (1). Reading details in this and that little structural feature. It's all so romantic and adventurous, they write book after book (2). Not that those in other disciplines are any better (3), but without independently derived supporting evidence it's all craps(4). Everything ties together.
1. http://www.paulawalla.com/pics/witch_zulu.jpg
2. http://www.publishamerica.com/greetingcardpro/images/big/1-4137-0818-8…
3. http://www.rpgnow.com/products/product_2258.jpg
4. http://www.vivalasvegasblog.com/Images/Aug2005/craps_dice-thumb.jpg
"Are there any other domesticated animals that have anywhere near the range of morphologies that dogs have?"
Chickens. And talk about traits that would be deleterious in the wild: domesticated chickens are quite possibly the dumbest animals alive. My wife had a chicken that was so stupid, on a hot day, instead of staying outside where it was cool, it returned to the hen house and stayed until it died. How is that for anecdotal evidence? (not to mention selection)
In other news, Dave Scott has been booted from the moderation of UD. http://www.uncommondescent.com/index.php/archives/1330.
Here's another article about domsticating foxes:
Dogs of Rarotonga: On a remote Pacific island, the local strays look a lot like their earliest ancestors. Domestication, they show, has its share of evolutionary side effects
http://www.discover.com/issues/jun-04/features/dogs-of-rarotonga/?page=3
And yes, most of the article is about foxes
Well, it points out here that science places an absolute upper bound of 60,000-90,000 years on the most recent human ancestor, since that's when "Y-chromosomal Adam" live
You might try actually reading what you cite:
The date of "Y-chromosomal Adam" has little bearing on anything; "the 20 or 30 different human groups" could have developed before or after him. All we know is that all living males received some part of their genetic inheritance through him -- but we also received some part of our human inheritance from numerous males who lived before him (but none of those males contributed to the entire male population).
Oops, I misspoke. All of Y-chromosomal Adam's male ancestors also contributed to the entire (modern) male population, of course.
More oops: and many others could have too (as the article says, "the existence of an MRCA does not imply any sort of population bottleneck").
I probably should have just quoted the line about not implying any sort of population bottleneck, which is true, and then shut up, but maybe I can unbotch this:
Y-chromosomal Adam is only relevant to entirely male lines. So all of Y-chromosomal Adam's ancestors through entirely male lines (i.e., his father, paternal grandfather, paternal grandfather's father, etc.) are also contributors to all living males' Y chromosomes, but no one else more ancient than Y-chromosomal Adam is, because whatever contribution we got from them must have passed through a female at some point.
Don't forget the Goats.
"Are there any other domesticated animals that have anywhere near the range of morphologies that dogs have?"
Gary--Dogs definitely have the greatest range of any domestic animal--there ARE lots of different chicken and pigeon breeds, but much of their diversity comes from differences in feathers, feet and other "surface" characters. Dogs have the greatest diversity of sizes and of skull shapes. It makes sense--dogs have been domesticated the longest and are used for the greatest variety of tasks, while cats for example have been used only for controlling vermin and as pets.
At the recent evolution meetings in Stony Brook, someone gave an interesting talk comparing dog skulls to those of wolves of known ages. Her conclusion was that dogs are not neotenous wolves, but are instead proportionate dwarves relative to adult wolves. The odder dog skulls (think of pugs) differ from wolves in several different unique ways, not as would be expected from neoteny.
BTW, there was a good retrospective on the Siberian fox domestication project in American Scientist about 2 years ago. As I remember it, the selection for amiability produced foxes with lower hormone levels, and the other dog-like traits that showed up in the population (white spots, drooping ears, etc.) were consequences of the hormonal changes. Neat stuff--and perfectly good evolutionary biology! Makes you wonder if Dembski actual READS anything, or if he starts writing as soon as his eyes pass over a newspaper headline.....
I'm hearing a lot of common misconceptions about domestication. Darwin's studies, for example, dealt entirely with breed development, not the process of initial domestication. Also, for dogs at least, what we call breeds are a very recent phenomenon (most are less than 200 years old). The very first morphologically distinct varieties came into existence only about 4,000 years ago, with the bulk arising during the Roman period (ca. 3,000 years ago). The extremes in diversity we now take for granted are not a significant feature in dog history: dogs world-wide were a generalized, dingo-like animal for close to 10,000 years before diversity in size and form became evident.
Dog domestication is actually a facinating evolutionary issue and one which deserves much more serious attention by biologists. I completed my Ph.D. on the topic two years ago. I took a very critical look at both anthropological and biological assumptions and misconceptions. I'm a zoologist, I wanted a plausible biological explanation for how a wolf could turn into a dog (that sticky issue Darwin glossed over): the initial tranformation of wild to domestic form. My research suggests a hormonal mechanism may account for all of the changes we see, not only for domestication but for other speciation events as well and I developed a simply paradigm to explain it.
For those interested, I have a book just out on the topic called, "Rhythms of Life: Thyroid Hormone and the Origin of Species" (see www.rhythmsoflife.ca). Background, table of contents and first chapter available on the site. Lest anyone think this a ploy for sales, I will gladly supply a pdf of my dissertation free if you use the contact page on the website to ask for one. The book IS an updated and expanded version and may appeal to those with less specialized backgrounds (my accountant read it with no problems), but still has all of the references. The theory is not only scientifically sound but eminently testable. It is guaranteed to give you a new appreciation for the importance of domestication to evolution, and lots of food for thought.
I think that Dembski just feels comfortable in the company of literal sons of bitches. Has anyone checked any dog's blog to see what the dogs themselves think of Dembski?
And a datum on how the wolf is still in the dog was a blurp in USAToday about a women in Greensburg, PA who was keeping several wolf-dog hybrids as pets (against the advice of humane society agents.) She was found dead in their pen in her backyard - bled to death after being mauled by them.
The unfair part is that the hybrids were euthanized. Basically being punished for being true to their natures I guess.
someone said:
"science places an absolute upper bound of 60,000-90,000 years on the most recent human ancestor, since that's when "Y-chromosomal Adam" lived"
Not necessarily correct. There are fertile xx-y females and hence the fertile x-yy males. This opens the door to recombination and gene conversion. Such events will erase differences and make the diversity of the y chromosome less than would be seen there were no recombination. Using the simple model of pure xx and xy inheritance, this would result in an artificially low time of divergence.
I would like to cut to the heart of the matter by pointing out that "thinga-ma-bobs" is actually spelled "thingamabobs".
I hope that clears up all this controversy.
-g
The problem with diversity in poultry is that it is usually seen as a single use commercial animal so that factory farming is actually leading to a precipitous loss of poultry breeds (along with hogs, cattle and other agricultural animals) The dominant turkey breed has such a pronounced breast that it is now incapable of breeding except by AI. (that would be something that would not be passed on to succeeding generations in the wild)
Dogs are the ultimate multiuse domesticated animal. Consider the number of breeds used just for the purpose of sheepherding. I believe twenty or more breeds were more or less bred specifically for the purpose of sheepherding, sheepguarding, etc.
I would note that this breed diversity does not seem to develop among cultures that consider dogs to be food animals excusively.