Researchers Trace Evolution to Relatively Simple Genetic Changes

In a stunning example of evolution at work, scientists have now found that changes in a single gene can produce major changes in the skeletal armor of fish living in the wild.

The surprising results, announced in the March 25, 2005, issue of journal Science, bring new data to long-standing debates about how evolution occurs in natural habitats.

“Our motivation is to try to understand how new animal types evolve in nature,” said molecular geneticist David M. Kingsley, a Howard Hughes Medical Institute investigator at the Stanford University School of Medicine. “People have been interested in whether a few genes are involved, or whether changes in many different genes are required to produce major changes in wild populations.”

The answer, based on new research, is that evolution can occur quickly, with just a few genes changing slightly, allowing newcomers to adapt and populate new and different environments.

In collaboration with zoologist Dolph Schluter, at the University of British Columbia, Vancouver, Canada, and Rick Myers and colleagues at Stanford, Kingsley and graduate student Pamela F. Colosimo focused on a well-studied little fish called the stickleback. The fish — with three bony spines poking up from their backs — live both in the seas and in coastal fresh water habitats all around the northern hemisphere.

Sticklebacks are enormously varied, so much so that in the 19th century naturalists had counted about 50 different species. But since then, biologists have realized most populations are recent descendants of marine sticklebacks. Marine fish colonized new freshwater lakes and streams when the last ice age ended 10,000 to 15,000 years ago. Then they evolved along separate paths, each adapting to the unique environments created by large scale climate change.

“There are really dramatic morphological and physiological adaptations” to the new environments, Kingsley said.

For example, “sticklebacks vary in size and color, reproductive behavior, in skeletal morphology, in jaws and teeth, in the ability to tolerate salt and different temperatures at different latitudes,” he said.

Kingsley, Schluter and their co-workers picked one trait — the fish's armor plating — on which to focus intense research, using the armor as a marker to see how evolution occurred. Sticklebacks that still live in the oceans are virtually covered, from head to tail, with bony plates that offer protection. In contrast, some freshwater sticklebacks have evolved to have almost no body armor.

“It's rather like a military decision, to be either heavily armored and slow, or to be lightly armored and fast,” Kingsley said. “Now, in countless lakes and streams around the world these low-armored types have evolved over and over again. It's one of the oldest and most characteristic differences between stickleback forms. It's a dramatic change: a row of 35 armor plates turning into a small handful of plates - or even no plates at all.”

Using genetic crosses between armored and unarmored fish from wild populations, the research team found that one gene is what makes the difference.

“Now, for the first time, we've been able to identify the actual gene that is controlling this trait,” the armor-plating on the stickleback, Kingsley said

The gene they identified is called Eda, originally named after a human genetic disorder associated with the ectodysplasin pathway, an important part of the embryonic development process. The human disorder, one of the earliest ones studied, is called ectodermal dysplasia.

“It's a famous old syndrome,” Kingsley said. “Charles Darwin talked about it. It's a simple Mendelian trait that controls formation of hair, teeth and sweat glands. Darwin talked about `the toothless men of Sind,' a pedigree (in India) that was striking because many of the men were missing their hair, had very few teeth, and couldn't sweat in hot weather. It's a very unusual constellation of symptoms, and is passed as a unit through families.”

Research had already shown that the Eda gene makes a protein, a signaling molecule called ectodermal dysplasin. This molecule is expressed in ectodermal tissue during development and instructs certain cells to form teeth, hair and sweat glands. It also seems to control the shape of - bones in the forehead and nose.

Now, Kingsley said, “it turns out that armor plate patterns in the fish are controlled by the same gene that creates this clinical disease in humans. And this finding is related to the old argument whether Nature can use the same genes and create other traits in other animals.”

Ordinarily, “you wouldn't look at that gene and say it's an obvious candidate for dramatically changing skeletal structures in wild animals that end up completely viable and healthy,' he said. "Eda gene mutations cause a disease in humans, but not in the fish. So this is the first time mutations have been found in this gene that are not associated with a clinical syndrome. Instead, they cause evolution of a new phenotype in natural populations.”

The research with the wild fish also shows that the same gene is used whenever the low armor trait evolves. “We used sequencing studies to compare the molecular basis of this trait across the northern hemisphere,” said Kingsley. “It doesn't matter where we look, on the Pacific coast, the East coast, in Iceland, everywhere. When these fish evolve this low-armored state they are using the same genetic mechanism. It's happening over and over again. It makes them more fit in all these different locations.”

Because this trait evolves so rapidly after ocean fish colonize new environments, he added, “we wondered whether the genetic variant (the mutant gene) that controls this trait might still exist in the ocean fish. So we collected large numbers of ocean fish with complete armor, and we found a very low level of this genetic variant in the marine population.”

So, he said, “the marine fish actually carry the genes for this alternative state, but at such a low level it is never seen;” all the ocean fish remain well-armored. “But they do have this silent gene that allows this alternative form to emerge if the fish colonize a new freshwater location.”

Also, comparing what happens to the ectodysplasin signaling molecule when its gene is mutated in humans, and in fish, shows a major difference. The human protein suffers "a huge amount of molecular lesions, including deletions, mutations, many types of lesions that would inactivate the protein," Kingsley said.

But in contrast, “in the fish we don't see any mutations that would clearly destroy the protein.” There are some very minor changes in many populations, but these changes do not affect key parts of the molecule. In addition, one population in Japan used the same gene to evolve low armor, but has no changes at all in the protein coding region. Instead, Kingsley said, “the mutations that we have found are, we think, in the (gene's) control regions, which turns the gene on and off on cue.” So it seems that evolution of the fish is based on how the Eda gene is used; how, when and where it is activated during embryonic growth.

Also, to be sure they're working with the correct gene, the research team used genetic engineering techniques to insert the armor-controlling gene into fish “that are normally missing their armor plates. And that puts the plates back on the sides of the fish,” Kingsley said.

“So, this is one of the first cases in vertebrates where it's been possible to track down the genetic mechanism that controls a dramatic change in skeletal pattern, a change that occurs naturally in the wild,” he noted.

“And it turns out that the mechanisms are surprisingly simple. Instead of killing the protein (with mutations), you merely adjust the way it is normally regulated. That allows you to make a major change in a particular body region - and produces a new type of body armor without otherwise harming the fish.”

So why does NS as the theory of Evolution fail to provide: ...

First of all, what O what is NS as the theory of Evolution? Why do none of you creationists know how to state what the theory is?

The Darwinian Theory of Evolution is that the species of life on Earth originated by common descent via a mechanism of random variation and natural selection. You ignore common descent, even though you obviously question it if you are arguing (as you are) that holes in the record are real holes in the history. That can only mean you are arguing for separate creation, which means you think somebody with some pretty advanced capabilities is running around poofing new things into being suddenly. That has implications for some of your later protests.

Most of your creationist confreres throw away natural selection and foam at the mouth all day about randomness won't do this or that. They have that all wrong, too. While your approach is different, it's still wrong. None of you correctly state the theory you are claiming to be wrong. That's dazzling.

The best list of predictions and potential falsifications is in the 29+ Evidences for Macroevolution. It's basically organized along the lines of prediction, potential falsification, and actual evidence. Your personal list is a field of strawmen which would as well be applied to meteorology, astronomy, or any other field with chaotic interactions. Being supposedly familiar with TO, it's funny you don't know any better.

Talk origins admits there are very few transitional species in the fossil record.

Their Transitional Vertebrates FAQ lets you trace fish transitioning to elephants, as Ichneumon has demonstrated at times. Good thing the fossil record isn't any sketchier, huh?

So why do you believe that any of these species trees are unable to reproduce with their ancestors? Morphology?

Because I can't reproduce with any of my ancestors? How dumb do you want to play this?

I'm not a creationist. Don't go there.

That must be in the talking points memo for June. All the other creationists are lying about who they are, too. It has happened once before, back sometime in 2000 or so. This, too, will pass.

Kathleen Hunt issues the challenge that I quote in post 559, and what is your answer?

1) You pretend to not be a creationist. Hint: KH doesn't care what church you go to. You are denying common descent when you thump the table on "lack of transitionals." She's still talking to you. Her challenge is still a challenge for your supposed objection. Read it again.

BTW, an Old Earth Creationist is still a creationist. If you don't accept common descent and aren't too big on the Raelians, that doesn't leave much, does it?

2) You play Twist and Shout with the presence of several instances of species-to-species morphing sequences in the horse record, the very thing that's not supposed to exist at all. That there are "only a few" of these is proof that all the rest of the genera on that chart aren't transitional?

You have to be a creationist. You aren't smart enough to be anything else.

I don't find the morphological forms of NS to be either compelling or useful.

I've already answered this twice. Let's make it three. The morphological evidence agrees with all the other lines of evidence. You have not answered the objection, only restated your personal incredulity. Militant ignorance, the hallmark of the creationist.

Note also the dishonesty of creationists claiming that there are no transitional forms, then trying to throw out the transitional forms as "mere morphological evidence" when they are presented. If you make the claim that biologists and paleontologists are scratching their heads because there are in the fossil record NO INSTANCES of things intermediate in form and time making a graduated series between Things A and Z, then it should be impossible to cite instance after instance after instance after instance in which such series are known.

Creationists repeatedly try for the first claim and then retreat seamlessly with no explanation or apology to dismissing the significance of what they claimed not to exist. Which is another way you fit the profile. Blatant, sneering dishonesty.

NS

Evolution is the phenomena and NS is the theory.

You're a scientist, or are you pretending.

NS has problems. ID has no basis, unless there are aliens or something. Both ID and NS do not exhibit prediction as a theory.

You can't even adhere to a rigorous definition of species. If you don't have rigorous defintions, how can you even call something a theory. You're in Red Queen territory.

Get real VadeR...the first sign of real science is being able to accept the warts on a theory.

As for the KH challenges to IDers, you do know that requiring the opposition to prove you are not right is a logical fallacy. Real science would announce the warts on a theory and try to find a way of explaining them. You aren't even questioning whether the Stickleback has 50 species or if they are really sub-species. Real science asks those kind of sticky, oops I might be wrong questions.

Dogmatic answers are coming from Evolutionists. IDers don't have anything worthwhile to add to NS. But they sure have the right to ask pointed questions. Dogmatic Evolutionists sure hate answering those questions.

>>A Question for Creationists: Creationists who wish to deny the evidence of horse evolution should careful consider this: how else can you explain the sequence of horse fossils.<<

I asked you a simple question that this "challenge" posed. Can you be reasonably sure that none of these horses can reproduce successfully with each other?

You don't know.

Taxonomy and morphology are good classification schemes, but even in that they are limited WRT the fossil record.

So if I say prove it, it is with love of science, and the scientific method. What future prediction has NS Evolution brought to the advancement of science?

Hint, they are all weak.

By the way, you need to study more philosophy, especially WRT fallacious reasoning and the scientific method.

With Love!
DK

Evolution is the phenomena and NS is the theory. You're a scientist, or are you pretending.

I showed you what was wrong with this and you simply repeat. Darwin agrees with me. Who agrees with you?

As for the KH challenges to IDers, you do know that requiring the opposition to prove you are not right is a logical fallacy.

Occam's Razor is not a fallacy. The horse series looks like evolution. The challenge to people like you who do not accept it as what it looks like is to provide some rational alternate scenario. You are dodging. Why is that, since (BWAHAHAHAHAHAHAHAHAHAHAHAHAHA!!!) you are not a creationist?

Dogmatic answers are coming from Evolutionists. IDers don't have anything worthwhile to add to NS. But they sure have the right to ask pointed questions. Dogmatic Evolutionists sure hate answering those questions.

Maybe it's because we answer them on every thread and the militant ignoramuses show up with amnesia every few hours or less?

Here's a quiz for you. 1. What have I cited to you as wrong with your objection to morphology as useless? 2. Give a brief statement of Darwin's Theory of Evolution.

By the way, you need to study more philosophy, especially WRT fallacious reasoning and the scientific method.

You're projecting here, nothing more.

Gee, I don't know if I'm up to the challenge?

LOL

Are you for real?

Your feelings of inadequacy are not my concern. Truth and method are.

We make up rules to understand nature. We make them up AFTER observation. Nature does not OBEY them. The rules are made up and are just representations for convenience. Whether it is mathematical convenience, theoretical convenience or whatever, they only represent NATURE and our observations about Nature. The rules we make up, come after observations. We need this as a tool to try to limit the necessary information to make a decision.

Very few rules are perfect. Our values for both Pi and E are only approximations. I challenged you to name a "perfect" rule that forces nature to obey it. You put the cart before the horse, as someone would say.

Or, if you're Maxine Waters, you put the horse before the cart. (I love that mistake)

Your feelings are hurt. Sorry. It is a big bad beautiful universe out there. If you want comfort and people cheering you on when you are wrong, post in a nicer area. Evolution and creation arguments are the most contentious on FR.

All the best!

DK

Dodging the question again.

Can you prove they are different species?

Not a creationist, sorry guy!

NS does not have predictive qualities. And...thanks to you...when I went back to the original story, about the sticklebacks, I found this gem.

>>“It's rather like a military decision, to be either heavily armored and slow, or to be lightly armored and fast,” Kingsley said. “Now, in countless lakes and streams around the world these low-armored types have evolved over and over again. It's one of the oldest and most characteristic differences between stickleback forms. It's a dramatic change: a row of 35 armor plates turning into a small handful of plates - or even no plates at all.”

Using genetic crosses between armored and unarmored fish from wild populations, the research team found that one gene is what makes the difference. <<

It seems the Stickleback crosses are sub-species crosses, and not species. I'm sure they would have mentioned genetic engineering in the article otherwise.

It's red hair vs. blonde (in the Stickleback form). I'm sure I don't have to explain that comment to you, do I VadeR.

DK

Misrepresenting NS and evolution is common. This article is neither rigorous nor evidence related. It is crappy reporting about crappy science.

Are you a crappy scientist VadeR?

Gees VadeR, you are tedious, even for an imagined scientist. I've asked for a prediction from NS, and you can't give it. Theories, prediction...reality...scientific method.

Something future related. You're really good at not responding to questions. What does NS add to biology outside of morphology and taxonomy?

NS does not provide results. Why should we fund it?

The horse series looks like evolution. <<

NS. You do remember the theory we are discussing. NS and evolution are not the same. As a scientist, you can remember the difference between an observation and the theory...right?

You should be the first one questioning this article. Especially on the species definition. You did not.

Crappy science, crappy logic, crappy theory. That is why those IDers give you heartache.

DK

Who agrees with you?
Logical fallacy.

Occam's Razor is not a fallacy. The horse series looks like evolution. The challenge to people like you who do not accept it as what it looks like is to provide some rational alternate scenario. You are dodging. Why is that, since (BWAHAHAHAHAHAHAHAHAHAHAHAHAHA!!!) you are not a creationist?

Ad hominem.

Occam's razor assumes you have a theory, and it is useful in prediction. Are you reading your responses...the horse series looks like evolution...not NS the theory.

Are the horses different species? Untestable theory is a fallacy...with a name.
http://www.datanation.com/fallacies/explan/untest.htm

Can you prove they are different species?

What are? Hyracotherium and Equus? One is a terrier-sized critter with lots of toes on the front and back feet. One is a horse.

Figure 6. Stages in horse evolution showing the reduction in the number of toes and foot bones. Forefeet above, hind feet below. (A) Hyracotherium, a primitive early Eocene horse with four toes in front and three behind, (B) Miohippus, an Oligocene three-toed horse, (C) Merychippus, a late Miocene form with reduced lateral toes, and (D) Equus. (From Vertebrate Paleontology by Alfred Sherwood Romer published by The University of Chicago Press, copyright © 1945, 1966 by The University of Chicago. All rights reserved. This material may be used and shared with the fair-use provisions of US copyright law, and it may be archived and redistributed in electronic form, provided that this entire notice, including copyright information, is carried and provided that the University of Chicago Press is notified and no fee is charged for access. Archiving, redistribution, or republication of this text on other terms, in any medium, requires both the consent of the authors and the University of Chicago Press.)

Taxonomy, Transitional Forms, and the Fossil Record.

What is supposed to be the same? What is your story here? Why can't Kathleen Hunt get an answer? If you supposedly not being a creationist is an answer, why does the question still remain even if it is edited to be non-God-specific?

Did ~~God~~ Something that wasn't evolution create Hyracotherium, then kill off Hyracotherium and create some Hyracotherium-Orohippus intermediates, then kill off the intermediates and create Orohippus, then kill off Orohippus and create Epihippus, then allow Epihippus to "microevolve" into Duchesnehippus, then kill off Duchesnehippus and create Mesohippus, then create some Mesohippus-Miohippus intermediates, then create Miohippus, then kill off Mesohippus, etc.....each species coincidentally similar to the species that came just before and came just after?
~~Creationism~~Anything-but-evolutionism utterly fails to explain the sequence of known horse fossils from the last 50 million years. That is, without invoking the "~~God~~Something That Wasn't Evolution Created Everything To Look Just Like Evolution Happened" Theory.

You're still dodging. You have no answer, and lack even the integrity to acknowledge the problem posed by ... the evidence you claim not to even exist. Why is each species "coincidentally" similar to the ones that came just before and just after? Every time?

Not a creationist, sorry guy!

Funny, but you not only deny the dreaded "NS," but also "CD." (Common descent.) That's the point of arguing from gaps in the record as real gaps in the history. That's what you're doing. Especially when one continues to do so even as gap after gap after gap has filled in since 1859.

So what are you supposed to be? Why can't you cite the "horse fraud" you claimed and I asked you for twice. Why haven't you cited one shred of literature in support of your position?

Because the only literature you could possibly cite for your slithery evasions is creationist literature. And that's what you're lying about being.

Are you thinking about how this looks? One of my many descriptions of creationism is "Grownups behaving very badly in public." How can you imagine no one can see through your charade here? This insults the intelligence of the lurkers.

Misrepresenting NS and evolution is common.

You do it every post, apparently. No creationist ever states the theory of evolution correctly. You have refused to do so. QED. You have also refused to recapitulate my own reply to your "mere morphology" dismissal. Religious horror? QED. Don't bother now. Too late. You flunk.

Are you a crappy scientist VadeR?

If I were a scientist, I'd have to take some remedial math in a hurry. I don't have to ask if you're one, but feel free to claim anything you think helps you.

"Why does evolution need an increase of 'information'?

"1)to get something an organism never had, not just modify or "turn off" or "turn on" an existing program its the mechanism for bacteria resistance not the fact that it becomes resistant.

You miss my point. The idea of applying information theory to the genome, to give weight to the argument that a lack of this information implies the inability of the genome to create novel functions and organs, is at best a red herring. Originally it was used by biologists as a visualization aid with no intention of literally applying it to the genome. We do not yet have enough information about what and how DNA actually works to start applying something like IT. The IDists and other creationists use it as a sword rather than as a scientific tool.

"Why is Safarti's 'information' better than any other 'information'?

"2) I don't think its better or worse, its just not new, such as Gadus morhua doesn't have the stickleback information for "armor" now if Gadus morhua develops armor it would be a far better case (against the new info claim/for macro) since the MECHANISM that created the change would be seeming nonexistent in Gadus morhua previously.(ie..no mechanism for armor like stuctures has ever been observed on Gadus morhua)

I thought we were discussing information? The mechanism is separate from the content is it not? Anyway, the point of the article is the large change in morphology with little change in gene with no new 'information' added.

"Why does a mutation only decrease information?

"3)mutations don't only decrease, (I believe he used corrupt) it can decrease, or change existing information, the trick is to have a mutation be a creative force of addition.

Mutations can and do add sections to a DNA sequence. This is an increase in 'information'

"Why are there 'simpler' organisms than humans with larger information bases for their complexity level?

"4) the observational informational base is, I think, moot. what is lacking (I believe)is the demonstration (not explanations of "suggested" possibilities) that whatever that base is, it can gain information.

Are you saying that forensic evidence does not count? Or that the myriad ways of increasing sequence length does not add information?

"A letter by itself does not remotely resemble the phrase that is required. What is required is the entire phrase "To be or not to be, that is the question." You are trying to claim partial success every time a monkey types the correct letter in the right "bin." But you are implicitly assuming that you have knowledge of the final answer. There is no advantage in choosing one letter to hold over another unless you know the final destination. Further, one letter in isolation does not provide anything useful in uncovering the entire phrase, even though an individual letter is part of the final phrase. In my opinion, you are assuming the result you are trying to achieve and you are aiding it along the way. The letter T by itself, without the other 39 that follow, in the correct order, does not provide the required objective, nor does it approach the required objective unless the objective is known beforehand."

Actually, you are the one that specified the phrase, so you were also assuming the end phrase was known. I simply gave a method of reducing the time needed to accomplish the task. One that is closer to how evolution accomplishes its task.

I do feel that you have misunderstood what Huxley was trying to get across, that evolution can complete a trial and error experiment on an almost unlimited number of forms within a large time frame. From what I gather now from your second post to me is that you were equating the creation of a complex DNA sequence to Huxley's mind experiment. If that is the case, my expansion of your experiment would fail as you have suggested. Remember, Huxley knew nothing of DNA. However, if we carry your experiment a little further and bring it closer to Huxley's statement we see you are being a bit too limited in view.

Your point was that if one sentence was impossible to create then the entire works of Shakespeare would be even more difficult. Actually, in this instance, you are incorrect; the more possibilities of correct phrases the more likely the desired outcome. I doubt that Huxley was claiming that by chance a random monkey from the bunch will type the complete works of Shakespeare, but that many of the monkeys will contribute to the full set of works.

If we have one particular phrase in mind then your logic is correct, but if we have thousands of letter combinations that make up the many phrases of Shakespeare works available, the likelihood of any one phrase of the bunch being typed, goes up.

For example:
What is the probability that using a single die, one person will roll six sixes in a row? OK, how about if we change that. What is the probability that this person will roll six sixes, or six fives, or six fours or six threes or six twos or six ones in a row? Now lets take that and increase the odds some more. We now have six people throwing one die each. What is the probability that six in a row of any side on the die will occur?

Sorry to blather on for so long, but this is what Huxley was trying to get across.

BTW I suspect Huxley had a very good grasp of combinatorics and probabilities.

"Huxleys assertion was that the entire volume of Shakesperes work could be produced ... I have just given an example of the ridiculousness of the assertion."

I understood your purpose, I just felt your criticism was misapplied in this case.

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