Stop The Presses! It's All Over!
by JoyA news release this week from biologists at the University of Manchester in England reports some world-shattering findings…
St. Bernard Study Shows Human-directed Evolution at Work
They report that by looking at 47 St. Bernard skulls spanning a period of 120 years - since the time that the breed standard for these dogs was first defined - they could see that the skulls steadily conformed to these standards over time. Because the breeders of St. Bernard dogs had bred for those traits.
Whoa. You're telling me that dog breeders can breed toward desired traits? What'll they think of next… breeding black and white spotted milk cows or fast race horses?
Okay, that was admittedly snarky. But it's a little amazing to me what counts for Breaking Science News! these days. Oddly enough, the release doesn't mention the fact that all dogs - Chihuahuas to Great Danes - are the same species. They got their individual good looks by selective breeding. I learned that in the 3rd grade.
Now, humans have been selectively breeding livestock for thousands of years. They have learned a thing or two in all that time about selecting for desired traits. It works, too. We know this. The real *surprise* of this research comes at the end of the release…
"These changes are exactly in those features described as desirable in the breed standards. They are clearly not due to other factors such as general growth and they provide the animal with no physical advantage, so we can be confident that they have evolved purely through the selective considerations of breeders.
"Creationism is the belief that all living organisms were created according to Genesis in six days by 'intelligent design' and rejects the scientific theories of natural selection and evolution.
"But this research once again demonstrates how selection — whether natural or, in this case, artificially influenced by man — is the fundamental driving force behind the evolution of life on the planet."
There you have it, children. The ability of humans to select for desired traits gives us NEW confidence that evolution is true because selection works, and that explains everything. Even better, it proves creationism false. By the way, creationism is Literal Genesis Intelligent Design that rejects the notion that dog and cattle and horse and cat and chicken (et al.) breeds are the result of selective breeding. As well as the 'scientific notion' of evolution altogether.
You know, if you spend any time reading science news releases, you might start to wonder who pays for all this wasted time. And whether these people have real-world skills they might use to become productive members of society someday. Luckily, I'm jaded. Some of this stuff is pure propaganda.
October 25th, 2007 at 9:46 pm
From the link:
Money was actually alloted so that a "study" could show that intelligent design debunks an extremely limited view of creation. That Trust has nothing better to do with its money?
Comment by Bradford — October 25, 2007 @ 9:46 pm
October 25th, 2007 at 10:23 pm
Use of stock breeding - and in particular dog breeding - was a significant part of Darwin's evolution-by-selection thesis in 1859. The very idea that anyone on earth doesn't know you can selectively breed by intelligent design toward desirable traits is unimaginably stupid.
Yet all dogs represent a single species [ed.]. Not just over the last 120 years' worth of St. Bernard breeding, but in all other selective - intelligently designed - breeding programs for at least 5,000 years, more like 10 for sheep and goats and cattle. Chihuahuas are still the same species as St. Bernards.
Starting all over again at this late date with this old news looks to me like desperation.
Comment by Joy — October 25, 2007 @ 10:23 pm
October 25th, 2007 at 10:50 pm
Desperation or maybe just pandering to the expected "refutations of creationism." I don't think I've seen a sillier study than this.
Comment by Bradford — October 25, 2007 @ 10:50 pm
October 25th, 2007 at 11:07 pm
Bradford:
"The Expected" has been known for all these thousands of years, Bradford. They've no need to re-assert it now. This is such a huge Duh that I've just gotta wonder what the hell they think they're doing.
It does sort of coincide with the whole 'New Eugenics Movement' [NEM] as much as with the NAM. We've got NEM-NAMs here!
150 years later they still can't do anything more than promise us BarbieKenWorld. And they can't do that by selecting genes and engineering it for those who can afford it, and probably never can do that. So they're right back to square one. Selective breeding - Eugenics. You can't make such a thing work species-wide unless you're willing to prevent your outliers from breeding. St. Bernard breeders know that. I'm a Poodle Person (giant mutant mountain variety). I know it too.
Has anyone checked on the grants coming out of the British Eugenics Society and its multi-mutated subdivisions lately? Who is Leverhulme Trust?
Comment by Joy — October 25, 2007 @ 11:07 pm
October 26th, 2007 at 2:46 am
What mostly amused me about the article is the claim that creationism means God 'used intelligent design' to create all the world in 6 days. The only reason "intelligent design" is thrown into the article is to connect it to YEC and confuse the issue further. I suppose Michael Behe could say that he believes God intelligently designed life to give rise to man after howevermany millions/billions of years through evolution. But I think some science journalists would choke at the connections such a sentence would make.
Comment by nullasalus — October 26, 2007 @ 2:46 am
October 26th, 2007 at 3:24 am
Here's the abstract of the paper:
The bolded part seems to be the main point of the paper. Nothing about creationism in the paper at all.
Bradford:
Get off your high horse. You haven't even read the paper, just the rubbish they wrote in sciencedaily.com.
Comment by Raevmo — October 26, 2007 @ 3:24 am
October 26th, 2007 at 5:13 am
Seems to be the main point? You have access to the entire paper and have read all of it? Science Daily was not the only source reporting this as depicted. It would be odd for a group of news sources to get it wrong. But it's possible.
Comment by Bradford — October 26, 2007 @ 5:13 am
October 26th, 2007 at 5:37 am
Yes I have, and absolutely nothing about creationism there. They wouldn't allow such crass political statements anyway in a serious high-quality journal like Proc. R. Soc. B. The main point is about the dynamics of changes in skull shape during the last 120 years, as a result of selective breeding. The interesting thing is that allometric relationships between various aspects of skull shape apparently do not constrain the ability of selection to change only one of those aspects (say length) independently of the others. Weak genetic correlations apparently.
Comment by Raevmo — October 26, 2007 @ 5:37 am
October 26th, 2007 at 5:48 am
Raevmo:
Wow! Someone has an effective propaganda machine. Look at these stories. How many contain the line about creationism?
http://www.eurekalert.org/pub_...
http://www.physorg.com/news112...
http://www.upi.com/NewsTrack/S...
http://news.webindia123.com/ne...
http://www.inthenews.co.uk/new...
http://www.usguides.net/my.inf...
Comment by Bradford — October 26, 2007 @ 5:48 am
October 26th, 2007 at 6:08 am
All of them. Pretty bizar. I wonder if the quotes in all those stories come from the scientists themselves. I've sent an email to the U Man contact (Aeron Haworth) to ask what's this all about. Let's see what they have to say.
Comment by Raevmo — October 26, 2007 @ 6:08 am
October 26th, 2007 at 8:52 am
Quite so! Origin of Species, Chapter 1 - Variation Under Domestication.
Dogs are a single species with wolves, but sheep and cattle are usually classified as separate species from their wild form. In any case, it is evidence that reproductive isolation is a continuum.
Darwin: "It is certain, on the one hand, that the sterility of various species when crossed is so different in degree and graduates away so insensibly, and, on the other hand, that the fertility of pure species is so easily affected by various circumstances, that for all practical purposes it is most difficult to say where perfect fertility ends and sterility begins."
Dog breeding is of interest to scientists for many reasons, including their rapid evolutionary divergence, and their close relationship with humans. Dog Genome Project.
Comment by Zachriel — October 26, 2007 @ 8:52 am
October 26th, 2007 at 9:41 am
The pace of morphological change: historical transformation of skull shape in St Bernard dogs
(My previous comment is stuck in moderation.)
Comment by Zachriel — October 26, 2007 @ 9:41 am
October 26th, 2007 at 10:18 am
Bradford:
It would be odd for a group of news sources to get it wrong. But it's possible.
No, it's not. It's about par for the course. We've had other long discussions here that were based on confusion caused by dumb press releases. Rule of thumb should probably be that if you see something interesting in a press release, read the actual paper before blogging.
Contrary to Joy's first sentence, the press release is not from biologusts at the University of Manchester. Press releases are usually written by flacks in the university publicity office, and the scientists doing the study have very little control. At best, you'll get some out-of-context quotes or paraphrases that the publicity office thinks will drum up controversy. If you really want to know why a study was done and what the authors think it demonstrates, you have to read the paper.
Comment by Nick — October 26, 2007 @ 10:18 am
October 26th, 2007 at 10:39 am
Raevmo:
All of them. Pretty bizar. I wonder if the quotes in all those stories come from the scientists themselves.
Hardly surprising. They're all the same quote, probably culled from exactly the same press release. It's easy to have an "effective propaganda machine" when journalists are lazy.
In addition to Raevmo's points above, The paper is interesting because the response to selection was sustained over many generations. The selection didn't run up against limits that foiled the breeders' plans. Not earth shattering, certainly, but it's one thing to assume something is true and another to demonstrate it.
I'd bet that the quote about creationism probably came in a longer conversation about selection and its limits. It seems like a non sequitor in the press release, but it may have been in response to a direct question.
Comment by Nick — October 26, 2007 @ 10:39 am
October 26th, 2007 at 10:46 am
Oh, and I should say "Thank you" to Joy.
If she hadn't noticed that press release, I would never have seen that paper, and I wouldn't now know that changes in morphology are measured in "units of Procrustes."
Units of Procrustes. How awesome is that? It brightened my whole day.
Thank you.
Comment by Nick — October 26, 2007 @ 10:46 am
October 26th, 2007 at 11:00 am
Raevmo:
I know how press releases are handled in most media outlets, so added that last line about propaganda. What is to be communicated comes in the release from the institution, news outlets dutifully report it as science. Some will occasionally read it first themselves and edit out extraneous or unrelated information, but not one of the outlets Bradford linked (I saw only three or four this week) recognized this as blatant bull. And not one bothered to vet it before passing it along as if it were news.
Here is the actual release on UManchester's 'News' page. It reads just as it reads in the media outlets, so it is there that the propaganda originated.
Zach:
Dog breeding is of great interest to dog breeders too. And dog fanciers, and all communities of humans who rely upon working dogs to make their living, etc. Wonderful, fascinating creatures. Though I once visited an English Bulldog breeder in Savannah and saw for myself some of the sad and bizarre results of "breeding to standard." And those were the outliers they didn't have the heart to kill outright. There were some of those in every litter too. These are genetic deformities maintained artificially - more "devolution" than evolution.
And of the not-so seriously messed-with breeds (like St. Bernards and Giant Mutant Mountain Poodles), the breeding to standard results in seriously shortened, painful lives and susceptibility to certain diseases. Hardly any of them could survive on their own in the wild *as* their selected breeds. The only way they could save themselves is by crossing wild to alleviate the genetic stress and revert to your basic Carolina Dog - Old Yeller.
Most of our domestic stock breeds could not survive without humans unless they crossed wild. With the possible exception of large pig breeds. Again, that seems more like "devolution" than evolution.
That selective breeding works to get consistently deformed generations is nothing new. We've known this for thousands of years and there's instructions right there in Genesis. It still doesn't 'prove' anything but that there is variation and selective breeding works. Duh.
Comment by Joy — October 26, 2007 @ 11:00 am
October 26th, 2007 at 11:16 am
Nick:
All they had to do was visit Madison Square Garden for the Westminster dog show. They'd have seen almost all the different breeds of dogs in one place at one time, and if they used their eyes and hands (like dog judges do to check for the standards) they'd have noticed a large degree of conformity to those standards in all shown representatives of the different breeds.
IOW, you'll get a pack of St. Bernards competing for best-of-breed who all look amazingly alike and all of whom display breed standard traits. Go next door and you'll see a pack of Irish Wolfhounds competing for best-of-breed and they'll all be amazingly alike too. Same with Chuhuahuas, Lhasa Apsos, Akitas, Malamutes, Border Collies, Poodles, Bulldogs, Jack Russells, etc., etc., etc.
I suppose it would surprise you to learn that the best-of-breed awards - at all levels and for all kennel club shows - translate into big bucks for the owners of the dog, who will sire or dam following generations (for large fees) of show dogs other owners hope to make big bucks with. BECAUSE they are best-of-breed showing all the right traits. These dogs are highly inbred for a reason.
Comment by Joy — October 26, 2007 @ 11:16 am
October 26th, 2007 at 11:23 am
Let me say that this whole discussion (other than the fact that the published paper doesn't seem to say what the media says that it says) sounds very much like Dawkins' criticism of Behe's "Edge of Evolution". I don't think that Dawkins was misquoted.
Zachriel, lets get some simple honesty going here. Is it not true that it is very easy to breed animals for any characteristic available in the alleles present in a species — changing allele frequency is rather easy to do by breeding. Is it not also true that getting any variety that is not already available in the pre-existing allele mix is, well, a vastly slower process.
ps: Cows may be called their own breed, but they apparently can breed like rabbits with bison.
Comment by bFast — October 26, 2007 @ 11:23 am
October 26th, 2007 at 11:30 am
Joy:
All they had to do was visit Madison Square Garden for the Westminster dog show. They'd have seen almost all the different breeds of dogs in one place at one time, and if they used their eyes and hands (like dog judges do to check for the standards) they'd have noticed a large degree of conformity to those standards in all shown representatives of the different breeds.
Crufts maybe. If they'd visited Westminster, they'd have blog critics crawling all over them for wasted transatlantic flights.
But that wouldn't tell them the rate at which the traits varied, or how the traits varied in relationship to each other. That data in the paper are not data that you could gather by wandering around Westminster or Crufts and prodding the occasional dog. As I said, it's not earth shattering stuff, but it is an interesting new analysis, and judging by the paper, it probably wasn't very expensive at all.
I agree, though, that the press release was silly.
You know, if you spend any time reading science news releases, you might start to wonder who pays for all this wasted time. And whether these people have real-world skills they might use to become productive members of society someday.
If, by "these people," you mean the people who write press releases, then I think those are excellent questions to ask.
Comment by Nick — October 26, 2007 @ 11:30 am
October 26th, 2007 at 12:15 pm
Well, the U Man press officer got back to me. He did get those silly quotes regarding creationism directly from the scientists themselves, but I don't know in what context or in response to what questions.
Comment by Raevmo — October 26, 2007 @ 12:15 pm
October 26th, 2007 at 12:28 pm
Nick:
LOL! Yeah, but they DID get paid to do the work, so they could have taken in the Big Apple nightlife while they were at it.
120 years is exactly the amount of time the breed standards have existed. Why should it be a surprise that ever more conformity to those standards was accomplished in that time by selective breeding? Among show dogs there is far less variation than out in suburbia, but even in suburbia the AKC pedigrees will demonstrate a direct and not very distant line to a best of breed champion with all the right traits. And a lot of cousin breeding.
I'm not going to look up St. Bernard health issues because I can reply to what is common knowledge - they suffer hip dysplasia at a rate par with other big dogs, their puppyhood is extended (takes 2 years to get full grown) and they live on average less than 10 years. Wolfhounds check out more often at 5-6 years.
Standard/Imperial Poodles and Boxers are notorious for cancer. Cancers are endemic in smaller dogs too. I mentioned the deformed English Bulldogs. It made me literally sick to think that for every 'salvaged' pup they couldn't sell and didn't have the heart to kill, there were two others from the litter who were either stillborn or were euthanized immediately (I saw a picture of one pup that had a giant hole where its face should be). Why would you do that to a perfectly good dog? One of the salvage pups had legs of different lengths, the front ones so short he looked like a wheelbarrow. Another had a huge head and such a malformed non-muzzle that they had to feed him only liquids.
Luckily, most breeds are not radically deformed. You'll have this in champions of all sorts of breeds of critter. That magnificent Angus bull will produce valuable offspring reliably, so he probably won't end up on anyone's dinner table. Of the ranched Angus that does end up on dinner tables, there will be more genetic variability to keep them robust. We know what inbreeding is good (and bad) for.
Silly to the point of absurd! This research doesn't prove evolution, or anything new about evolution. The quoted remarks do misrepresent Creationism and ID rather humorously and for no apparent purpose. Darwin's observation that there is variation and that selection works was always entirely uncontroversial. It's not controversial now either.
Comment by Joy — October 26, 2007 @ 12:28 pm
October 26th, 2007 at 12:41 pm
Raevmo:
Thanks for taking the trouble, Raevmo. I suspect the researchers were asked why they thought their findings were so important that they qualified as hot news. I mean, it should be just a report on the conformity to standards over time as evidenced in the collection of skulls, which actually *is* something new. Most people don't save their dog's skulls to compare the generations, they just look at the dog, assess its conformity to standard, and sell or show it.
And thankfully, not all breeds come from breeding programs as ugly as that for English Bulldogs. They are genetically unstable even if you breed champions (as these breeders did). I wonder how many Georgians who just have to have a bulldog to demonstrate their support for the team know what horrors come out in the litter, or the ratio of euthanized animals to sellable merchandise. Though I don't expect the Marines care very much about that…
That's not evolution. It's considerable animal cruelty. It is still amazing to me that there are humans alive right now who believe strongly that we should do this to 'evolve' prettier people, for entirely aesthetic reasons. Variety is healthy. Conformity is not. And beauty, as always, is in the eye of the beholder.
Comment by Joy — October 26, 2007 @ 12:41 pm
October 26th, 2007 at 12:44 pm
Did anybody alert MikeGene?
Comment by Pez — October 26, 2007 @ 12:44 pm
October 26th, 2007 at 12:58 pm
LOL thats as blatant as you can get.
Comment by Guts — October 26, 2007 @ 12:58 pm
October 26th, 2007 at 1:41 pm
I loves me some Joy!
Comment by chunkdz — October 26, 2007 @ 1:41 pm
October 26th, 2007 at 1:58 pm
What a perfect example of conflation of words and definitions. See how 'intelligent design' is neatly linked to a six day creation. Of greater note is the common practice of referring to 'natural selection' and 'evolution' as theories. They are not. They are observations. Darwinism is the theory based on the observed facts of natural selection and the descent of species over time (evolution). Darwinists always do this. They point to some example of selection, or a bit of the fossil record and say that such evidence alone proves Darwinism.
As a side question, how come German Shepards and Chihuahuas are considered to be the same species? For physical reasons they cannot mate, and are therefore reproductively isolated. And how come German Shepards and wolves are classified as separate species when they have no problem mating and producing fertile offspring?
(My answer is that no matter what the selective pressures are on these animals and what kinds of freaks can be created from their gene pool, they all remain the same species because they have the same genome. Darwinists commonly classify animals with the same genome into different species in order to argue their claims, e.g. Galapagos finches.)
Comment by Stuart Harris — October 26, 2007 @ 1:58 pm
October 26th, 2007 at 2:10 pm
Nick:
I agree with your point about reading the paper but need to point out that it would clarify only the written views of the authors with respect to the study itself. Thanks to Raevmo's efforts we know this much more:
While there are still some unknowns it looks like someone has taken advantage of an old journalistic adage about retractions to headlines being buried in innocuous locations if retractions are made at all.
Comment by Bradford — October 26, 2007 @ 2:10 pm
October 26th, 2007 at 2:39 pm
Stuart Harris:
And how come German Shepards and wolves are classified as separate species when they have no problem mating and producing fertile offspring?
Just obsolete tradition, I think. For some reason, it has been traditional to give domestic animals different specific epithets than their wild ancestors (e.g. canis lupus and Canis familiaris, Bos taurus and Bos primigenius).
The Integrated Taxonomic Information System (http://www.itis.gov/index.html) indicates that Canis familiaris is now considered invalid. The accepted taxonomy is Canis lupus familiaris, so dogs and wolves are now considered the same species (with domestic dogs as a subspecies of Canis lupus). Similarly, Bos primigenius is now listed as a synonym of Bos taurus.
As for German Shepherds and chihuahuas, even if they cannot breed directly, they can share genes indirectly via intermediate breeds and thus are not reproductively isolated. They're an artificial version of a "ring species."
(My answer is that no matter what the selective pressures are on these animals and what kinds of freaks can be created from their gene pool, they all remain the same species because they have the same genome. Darwinists commonly classify animals with the same genome into different species in order to argue their claims, e.g. Galapagos finches.)
Not quite sure what you mean here, but I think you are using "genome" in a non-standard way. Perhaps "gene pool" would be better. How exactly are you determining that two animals have the "same genome?" Shared alleles? Ability to interbreed? Can all the species of Darwin's Finches interbreed?
Comment by Nick — October 26, 2007 @ 2:39 pm
October 26th, 2007 at 2:53 pm
Aw, Chunk! I love you too.
Stuart Harris:
Oh, I dunno. Some Chihuahuas are quite big (10-15 pounds) and some Shepherds are quite small (the 'real' ones aren't the big ones you usually see). Dogs will readily mate with whoever's in heat however they can, though such a cross brings puns like, "Who put her up to it?" and "How could he stoop so low?" §;o)
I think all our domestic dogs are basically grey wolf variants. Except Carolina Dogs, which are genetically closer to dingo. And mutts, who have some of both. I think most canines - wolves, dogs, dingos, coyotes - can crossbreed fertile offspring. Don't know if you can include foxes in that.
Good point. Judging from the reaction over at SciBlogs to Watson's gaff, it doesn't look like they're quite ready to be open about doing this with people yet.
Comment by Joy — October 26, 2007 @ 2:53 pm
October 26th, 2007 at 4:48 pm
Good job on spotting this one Joy! I was hopping somebody would. I had a good laugh after I read the original article on Physorg. Not only does the study fail to cast doubt on creationism, it doesn't even understand what creationism asserts.
Creationists believe that the original created organisms were rich in genetic information. After the creation event genetic information is lost as the original information is sorted through natural selection by the environment. As a result the descendants of the original species have less genetic information and are less able to adapt to changes in the environment and therefore more prone to extinction. Although the result of artificial selection, the St. Bernard is actually a good example of this.
Comment by Jehu — October 26, 2007 @ 4:48 pm
October 26th, 2007 at 7:34 pm
Jehu:
You're right. I'm fairly up on dog breeding because I have registered dogs and keep up with the shows. All the bluebloods suffer predictable effects of inbreeding.
Here is a list of hereditary defects most commonly seen in those English Bulldogs, at birth or developed. Puppies are increasingly delivered by Caesarian section because too many dams died when big heads got stuck.
"¢ Excessive skin folds - dermatitis and Demodectic mange, face and tail.
"¢ Folliculitis and Forunculosis - infections of hair follicles and deep skin structures.
"¢ Cataract, Distachiasis, entropion and ectropion - congenital eye issues.
"¢ Eversion of nictitating membrane - "cherry eye"
"¢ Abnormal dentition - placement, number and development of teeth
"¢ Cleft lip, cleft palate
"¢ Elongated soft palate
"¢ Hemivertebra - only half the vertebral structure is formed.
"¢ Hip dysplasia
"¢ Spina bifida
"¢ A variety of respiratory and cardiovascular issues, including arteriovenous fistula.
"¢ Dystocia - complications of birth.
Last but not least, Inverted Hind Feet, where the puppy is born with the hind foot paw pads facing up, not down.
The breed standard champions are outliers of a very diverse species, and some of them are genetically unstable, bred to express mutations that serve human aesthetics more than they can serve the poor dog.
Comment by Joy — October 26, 2007 @ 7:34 pm
October 26th, 2007 at 9:26 pm
That "vastly slower process" can be directly measured, such as in the St. Bernard study.
Comment by Zachriel — October 26, 2007 @ 9:26 pm
October 26th, 2007 at 10:19 pm
bFast said:
Zach responded:
Are you suggesting that the increasing conformity to breed standards over 120 years developed traits that didn't exist in the breed 120 years ago? I ask because that would be a silly assumption, given that the breed standards were established upon the best examples of the breed that existed 120 years ago.
St. Bernards had broad heads, angular bridge-forehead and pronounced brow ridges all along. These traits just got more exaggerated by breeding for the exaggerations.
Comment by Joy — October 26, 2007 @ 10:19 pm
October 26th, 2007 at 10:51 pm
Nick said:
Yes, the different "species" of Darwin's finches can and do mate, and produce fertile offspring. Separate groups of these birds have been defined as unique "species" simply by having different beak shapes and sizes, and by geographic locations.
This is simply a difference in gene frequencies among animals that have the same genome — just like dogs or peppered moths, or the collective shapes and colors of us humans.
Comment by Stuart Harris — October 26, 2007 @ 10:51 pm
October 27th, 2007 at 9:16 am
Not conformity to a specific shape, but an exaggeration of desired traits.
The pace of morphological change: "We discovered that features stipulated in the breed standard of the St Bernard became more exaggerated over time as breeders selected dogs that had the desired physical attributes."
These are pure bred animals with little variation in alleles. "This trend appears to be linear throughout the entire period and appears to be continuing." This is not mere allele shuffling.
Comment by Zachriel — October 27, 2007 @ 9:16 am
October 27th, 2007 at 9:58 am
They're classified taxonomically as species because they tend to retain those characteristics of beak shapes and size. In modern terms, they tend to maintain distinct breeding populations. Hybridization is rare, but not insignificant, in Darwin's Finches.
One of the most important evidences for the Theory of Evolution is that reproductive isolation is a continuum, as pointed out by Darwin in Origin of Species.
Darwin: "It is certain, on the one hand, that the sterility of various species when crossed is so different in degree and graduates away so insensibly, and, on the other hand, that the fertility of pure species is so easily affected by various circumstances, that for all practical purposes it is most difficult to say where perfect fertility ends and sterility begins."
Comment by Zachriel — October 27, 2007 @ 9:58 am
October 27th, 2007 at 7:54 pm
Stuart said:
Balderdash. Not all the different species of finches in the Galapagos can interbreed so far as anyone knows — but there's probably a good way to test Stuart's claim, at least partially. The Grants' research includes blood samples for DNA analysis of every individual in at least three species that should be interbreeding, by Stuart's claims. If they are not in fact separate species, Stuart could demonstrate that by DNA analysis, no?
In fact, all the Grants' records are available for other scholars to peruse and study. A 40-year longitudinal study should produce evidence in spades against evolution, if evolution is not accurate.
Of course, no creationist has ever bothered to look at the evidence, not even a creationist of the ID stripe.
The Grants define the species as separate species by a number of different criteria, any of which could be contested successfully if the Grants were in error.
When do you strike out for Princeton, Stuart? Never?
One almost gets the sense that creationists understand their ideas don't float, when they keep refusing to use the ideas as rafts to the new, non-Darwin theory.
Comment by edarrell — October 27, 2007 @ 7:54 pm
October 27th, 2007 at 8:53 pm
Zach:
Zach, skeletal development is primarily regulated epigenetically. If this were not true, there's no way humans would exist. That's a reproductive issue, but I believe there are ample studies out there of skeletal developments in selectively bred animals to cover skull broadening (and muzzle shortening, and overall size shrinking…) and brow thickening. That's how there can be so many varieties, all shapes and sizes, of dog. Who were ALL grey wolves (four of them, according to genetic analysis) who existed just 10,000 years ago in Northern China.*
ALL dogs represent a single species, and many biologists consider that species to be grey wolf.*
Thus it's not a matter of what alleles are present, it's a matter of expressing those that already ARE present.
Exemplars (those individuals which exhibit the traits prized) breed more exemplars and over time the traits emphasized are exaggerated. It's how selective breeding works. No one who has ever bred animals or dealt with registration pedigrees is surprised by the observations recorded in this examination of 47 skulls of St. Bernard exemplars. I say that honestly.
Zach to Stewart:
Are bird beak size and shape different from bone size and shape - you know, the dog breeds example? Is this a "Big Curved Beak" gene versus a "Small Pointed Beak" gene, or is it just a suite of what already exists, being expressed?
[* Exception: Carolina Dogs. These are more related to dingos.]
Comment by Joy — October 27, 2007 @ 8:53 pm
October 27th, 2007 at 8:57 pm
Joy makes a good point, one that is often lost by those who reject Darwin. He spent the first couple of chapters of Origin of Species backing the claim that there was already enough variation in most species to produce speciation without any additional mutation.
Comment by edarrell — October 27, 2007 @ 8:57 pm
October 27th, 2007 at 9:38 pm
edarrell:
Well, we'd have to add that into the ample evidence from dog breeding also. In that while cultivating a mutation or set of mutations toward an exaggerated goal (toy poodle, English bulldog, hairless Chihuahua, Basset hounds), one does not establish a new species.
Comment by Joy — October 27, 2007 @ 9:38 pm
October 27th, 2007 at 9:55 pm
Yes, they are different. Left to their own devices, most dogs will interbreed, indeed do interbreed; and without intervention, the gene pool quickly becomes intermingled. Darwin Finches tend to keep their separate identity, song being one mechanism of reproductive isolation.
Comment by Zachriel — October 27, 2007 @ 9:55 pm
October 27th, 2007 at 10:04 pm
Is their song genetically determined too?
Comment by Joy — October 27, 2007 @ 10:04 pm
October 27th, 2007 at 10:39 pm
Nature and nurture. There's some fascinating work in this field. For instance, male zebra finches are born with a certain innate song pattern, depending on species, that they then refine by exposure to other males, usually the father. Specific genes (FoxP1 and FoxP2) have been identified that influence song behavior. These genes are also involved in human speech, and affect homologous areas of the human and avian brain. And this has attracted the attention of those involved in human speech disorders.
Comment by Zachriel — October 27, 2007 @ 10:39 pm
October 27th, 2007 at 11:14 pm
Or maybe I should ask if birdsong is directly connected to beak size, as a genuine mutation, which all like-beaked birds of the species recognize per exclusivity of mating. Is this something biology knows "for sure," Zach?
Can I breed a new species of parrot by teaching it a new song? Can we breed a new species of rodent by teaching it a new maze?
I think you're grasping at straws. Birds are a whole lot smarter than you think, as well as much more creatively talented.
Comment by Joy — October 27, 2007 @ 11:14 pm
October 27th, 2007 at 11:43 pm
We crossed in posting, Zach. "Influence" doesn't suggest mutation. It suggests expression. Or, in this particular case, learning.
Comment by Joy — October 27, 2007 @ 11:43 pm
October 28th, 2007 at 9:47 am
Genuine mutation? As opposed to what? That cheap knock-off
Brand-X Mutation?Birdsong has been shown that it be correlated with, but not determined by, beak and body morphology (e.g. Darwin Finches). Mating signal diversification often facilitates rapid speciation. Other influences include adaptation to habitat acoustics, and through the cultural accumulation of copy errors (Grant and Grant). But it can also be shown (by raising chicks in the nests of related species, cross-fostering and hybridization allowing the manipulation of culture while fixing the genetic component) that birds learn songs based on an inherited template.
Birds certainly do exhibit cultural learning, but there is also an inherited component to birdsong.
Comment by Zachriel — October 28, 2007 @ 9:47 am
October 28th, 2007 at 11:05 am
Bradford wrote:
"Wow! Someone has an effective propaganda machine. Look at these stories. How many contain the line about creationism? "
Just curious - are you familiar with http://www.evolutionnews.org/ or http://creationsafaris.com/?
Comment by derwood — October 28, 2007 @ 11:05 am
October 28th, 2007 at 11:15 am
derwood:
Yes. Are you clear on the distinction between propaganda and up front editorializing? The former presents partial facts as news items and seeks to portray the author as a reporter and not an opinion giver. The facts are slanted to induce a targeted opinion from the reader.
Comment by Bradford — October 28, 2007 @ 11:15 am
October 28th, 2007 at 11:58 am
Zach:
As opposed to your constant confusion of expression for mutation, and now your conflation of learning with mutation. It's okay to admit that you assume all diversity is the result of random mutations because your theoretical framework tells you to assume that. It's not okay to pretend that your assumptions are established fact.
I have pointed out the press release's ridiculous claim to have falsified Creationism and a scarecrow version of ID by telling us something we've known for thousands of years. I have emphasized the FACT that for all the obvious differences between hairless Chihuahuas and St. Bernards, they are members of a single species traced to grey wolves in China.
Now you want us to believe that all Galapagos Finches - birds who do not display anywhere close to that kind of physical diversity - are different species by virtue of different size beaks. Even though the beak sizes change regularly according to what food is available, and these different 'species' can revert back to their previous 'species' when necessary.
You probably don't even see how silly that looks, do you?
Comment by Joy — October 28, 2007 @ 11:58 am
October 28th, 2007 at 12:54 pm
I pointed to an experiment with finches that uses cross-fostering and hybridization to separate the influences of heredity and culture.
Huh? I also said, "Birds certainly do exhibit cultural learning", knowledge handed down by learning. I'm not sure how much more plain I can be.
Detailed genetic studies have been done on finch speciation. Reproductive isolation is a well-observed phenomena. But species can hybridize. That's a primary evidence originally noted by Darwin.
Comment by Zachriel — October 28, 2007 @ 12:54 pm
October 28th, 2007 at 3:47 pm
Zach:
Good enough. Are their songs cultural or genetic?
I think it's entirely arbitrary labeling by those eager to interpret evidence in support of their preconceived notions. If they can hybridize and produce fertile offspring, the species designation is behavior related (learned) rather than genetically determined. Dogs, wolves, dingos, jackals, dholes, Pariah dogs (Carolina) and coyotes can hybridize and produce fertile offspring, they just don't in most normal situations.
They have developed estrus cycles unique to their kind, and this helps to prevent cross-breeding. Just not entirely. The timing of estrus cycles is expression. They all have 78 chromosomes in 39 pairs. [Canid Hybrids]
Maybe bird culture supplies mating exclusivity too. Think up a new song and teach it to the kids, pretty soon your can be fairly sure your descendants will choose a mate who knows that song. I suppose you could assert the assumption that cultural exclusivity per mating choices is genetically determined by random mutations in genes, thus different cultures signify different species. Go ahead and apply that on up the chain to humans, since your theoretical assumptions must apply across the board. Let's take it there and see what we've got.
If y'all are so sure you're right, you should be brave enough to defend your beliefs against the charge of political incorrectness.
Comment by Joy — October 28, 2007 @ 3:47 pm
October 28th, 2007 at 5:39 pm
The science indicates that there are both cultural and genetic aspects to birdsong. The cross-fostering and hybridization observations above are an example of how we can learn about some aspects of this relationship.
You seem to be confused on the species concept. There are several definitions, and species do not necessarily have clear edges. Reproductive isolation usually occurs over geological time-scales. As Darwin pointed out, it "graduates away" and "it is most difficult to say where perfect fertility ends and sterility begins."
These are good examples of how reproductive isolation "graduates away".
Humans are very closely related and form a single reproductive population.
Comment by Zachriel — October 28, 2007 @ 5:39 pm
October 28th, 2007 at 7:22 pm
Zach:
Gee, Zach. That's not so difficult. Cross them and see. A different number of chromosomes can determine who can interbreed and produce fertile offspring. A horse has 64 chromosomes, a donkey has 62 (some of them, anyway). Offspring end up with 63, which is not evenly divisible. The offspring (mule or hinny) is sterile if male, occasionally fertile if female. A mare hinny will produce a 100% horse if bred to a horse, or a 100% donkey if bred to a donkey (with one documented exception).
Of course, voles challenge this definition rather dramatically. Voles can have anywhere from 17 to 64 chromosomes, and in some species males and females have different numbers of chromosomes. That doesn't stop them from breeding like… er, voles. Voles also all look alike, no matter what species scientists call them today.
Comment by Joy — October 28, 2007 @ 7:22 pm
October 28th, 2007 at 8:55 pm
Another excellent example, this time nearly completely isolated gene pools. Lions and tigers are another example. They can breed and produce fertile offspring if confined, but there is virtually no gene flow in the wild. They maintain their separate identities and are reasonably considered separate species (but the same genus, Panthera).
Comment by Zachriel — October 28, 2007 @ 8:55 pm