Saltation and Lizards
Science
| July 15, 2008
| Tim
I do not believe the religion is the enemy of good science -- one would have to be largely ignorant of the history of science to sustain such a belief.
But I have increasingly come to believe that certain kinds of religious belief are indeed the enemy of good science. Why did it take fifty years for the Big Bang -- which seems an obvious implication of observations about entropy (and never mind Einstein's work) to be accepted, despite lots of evidence to the contrary? The Big Bang, it seems would have punctured not a few cherished materialist dogmas.
(People are religious animals, and atheists seem not at all exempt from this phenomenon. If anything, as Michael Crichton, G.K. Chesterton, Sam Harris (inadvertently) and others have observed, atheists often seem more prone to religious fanaticism than JudeoChristian counterparts.)
So Darwin has become an atheistic saint. Not a few critics have noticed that his original doctrine (which was falsifiable) has evolved (heh) into something rather less so. Just as some Christians resort to the fallacy of Pascal's wager, so also do Darwin's Priestly Caste argue we need to accept their doctrine because it is "the only theory" [1] we have. (And that makes it correct, how?) Meanwhile, on the social front, the Faithful are trying to create feasts and holy days for him. Even the Operating System which I am using to write this was named in his honor.
The big problem with Darwinism, however, is that it appears to be grossly wrong, on levels both casual and deep. Is the gene really the primary mechanism of evolution? Is a life-and-death struggle for scare resources really the main or only driving force for the production of new species? Does the fossil record really reveal a history of slow, gradual changes?
To the contrary, saltation -- the idea that new species appear suddenly -- remains the bane of NeoDarwinism. Wikipedia notes that saltation "defies the orthodoxy of evolutionary theory" -- that is, it flies in the face of the neo-Darwinist story.
So, all that said, what's wrong with this picture from a Darwinian perspective?
In 1971, biologists moved five adult pairs of Italian wall lizards from their home island of Pod Kopiste, in the South Adriatic Sea, to the neighboring island of Pod Mrcaru. Now, an international team of researchers has shown that introducing these small, green-backed lizards, Podarcis sicula, to a new environment caused them to undergo rapid and large-scale evolutionary changes.
“Striking differences in head size and shape, increased bite strength and the development of new structures in the lizard’s digestive tracts were noted after only 36 years, which is an extremely short time scale,” says Duncan Irschick, a professor of biology at the University of Massachusetts Amherst. “These physical changes have occurred side-by-side with dramatic changes in population density and social structure.” ....
Examination of the lizard’s digestive tracts revealed something even more surprising. Eating more plants caused the development of new structures called cecal valves, designed to slow the passage of food by creating fermentation chambers in the gut, where microbes can break down the difficult to digest portion of plants. Cecal valves, which were found in hatchlings, juveniles and adults on Pod Mrcaru, have never been reported for this species, including the source population on Pod Kopiste.
“These structures actually occur in less than 1 percent of all known species of scaled reptiles,” says Irschick. “Our data shows that evolution of novel structures can occur on extremely short time scales.
Again, what's wrong with this picture? Or rather, what's wrong with Darwinism, if this picture is true?
First, 36 years isn't enough time to allow slow, random mutations-by-chance to produce this new species or variety. Rather, it appears that the lizard's exposure to a new environment itself triggered a significant, rapid, and heritable changes. If "novel structures" (organs, etc.) can or do appear "on extremely short times scales", that tosses the whole Darwinian story about gradual adaptation out the window:
(1) Random mutation then isn't the proximate (nearest) source of the "information" needed to produce these structures, rather they must be an expression, at least partially, of some very sophisticated information / potential already present in the animal. The same thing appears to have been true regarding fish (bold added):
A long-held theory of the development of limbs is overturned by a study that shows the molecular wherewithal to make hands and feet was present long before the first fish took the momentous step on to land... “We found that the genetic capability seen in tetrapods to build limbs is present in even more primitive fish,” said lead author Marcus Davis, a postdoctoral fellow in Prof Neil Shubin’s lab at the University of Chicago.
In the same way, it would appear that although cecal valves occur only in a tiny percentage of lizard species, the information needed to produce them may be latent within most or all, and may have been there "all along" -- long before it could be "expressed" in a useful way. However we'd guess such information got there in the first place, it certainly wasn't by a fierce competition in which the expression of the "gene" (assuming said information is even coded on discrete genes) was the deciding factor!
(2) And what of the life and death struggle? The Darwinian picture is of a few survivors from a older species trying to survive among scarcity. The picture in this story -- which I might remind you is now a recorded fact, not speculation (like Darwin's musings) -- is instead of rapid change occurring instead amidst an abundance of food, and a multiplication of individuals:
Because plants provide a larger and more predictable food supply, there were more lizards in a given area on Pod Mrcaru. Food was obtained through browsing rather than the active pursuit of prey, and the lizards had given up defending territories.
Is this "evolution"? Sure, in the original sense of the word -- a mere change between shapes. "Evolution", in that sense, was accepted long before Darwin, and by many of his critics. But it's not Darwinian in the slightest.
As with the big bang, where a popular revisionist understanding of history imagines materialist scientists were always in favor of the theory (rather than fighting it, in the face of strong evidence, for decades) so too, I think, should this all pan out as I suspect, that Darwinists will claim they were right all along.
I don't mean to get political here, but there are a certain group of people who always insist, once they get done making some huge mistake, that it was really their "enemies" who did that. The 20th century eugenicists were socialist utopian Darwinists, but now people (who tend to share their proclivities) insist they were small-government Christians. The Communist movement was always part of the left, but now Communists are called (by today's socialists) "conservatives." They were atheists, but modern atheists insist now that Communism was "a kind of religion" (whereas they're sure their own beliefs aren't)?
Likewise, I suspect this will idea will move, as most radical ideas do, from "heresy" to having been "obvious" all along, with the Darwinists portrayed as the ones who first embraced it -- rather than the ones who have for decades worked tirelessly to play down the counter-evidence and suppress the necessary debate.
Even the Operating System which I am using to write this was named in his honor.
And it competed with Windows XP, which Microsoft internally named "Cairo" prior to release.
Darwin's OS's 'mascot' is named "Hexley" apparently.
You've gotta check out how they depict him.
I think the hat is supposed to be reminiscent of the old "Berkeley" (BSD)-style "demon" -- created by a guy named John Lasseter. (I hear he did some stuff with Pixar later on.) But it is an interesting choice.
And what of the life and death struggle? The Darwinian picture is of a few survivors from a older species trying to survive among scarcity. The picture in this story -- which I might remind you is now a recorded fact, not speculation (like Darwin's musings) -- is instead of rapid change occurring instead amidst an abundance of food, and a multiplication of individuals:
The new species wiped out the indigenous lizard populations, although how it happened is unknown, he said.
National Geographic
(Which is quite odd. Why did the original species disappear?)
Largely insect eaters, the half-foot long reptiles would find themselves on an island where insects were in short supply but plants were not.
Pod Mrcaru, just off the west coast of Croatia, is a "tiny rock in the middle of the water," Irschick said.
"You could walk from one end to the other in five minutes. It has a Mediterranean climate - hot and very dry. It's mainly rock with little shrubby plants sticking up out here and there. It looks very inhospitable," he said.
"Because plants are tough and fibrous, high bite forces allow the lizards to crop smaller pieces from plants, which can help them break down the indigestible cell walls," he said.
Richard Dawkins.net
Interesting how the Dawkins site focuses on scarcity. Though it's not entirely off base since it is a small island and the new lizards weren't adapted to eat the local vegetation. If you and I are in the middle of a forest with no food, it wouldn't help us much that termites could eat wood.
Also, I wonder how much of the lizard's genome was sequenced. Saltation and epigenetic re-expression of old traits is entirely believable as an explanation, but I doubt that the researchers sequenced more than a few loci.
Some other sites seem to mention that intestinal webs and diaphrams can form in the guts of human steroid users as well, due to the destruction-followed-by-healing effect of the drugs on the human gut. It seems worth asking if the structures would persist in a generation of lizards raised entirely on insects.
Of course, regardless of how this works out I agree with your point that the Neodarwinian synthesis seems to be springing holes, to be replaced by a different theory of evolution.
I think the hat is supposed to be reminiscent of the old "Berkeley" (BSD)-style "demon" -- created by a guy named John Lasseter.
Very true. More than anything, I just never understood why Microsoft had chosen the labarum as the symbol for their operating system. (The first two letters of "Christ" in Greek being Chi-Rho... thus microsoft codenaming XP 'Cairo.') XP seemed such an unusual and obscure choice for an OS symbol. But I saw "Hexley" and it all seemed to click; MS chose "XP" as a response to Darwin + Huxley.
Random realization there. Sorry it was slightly OT.
Huxley.
Sorry, as a response to Darwin + Hexley
Sorry for my absense. I got addicted to a game and was playing for a while. Lets see... yes, fanatical atheists... remind me again the last time atheists burn a person to death for heresy? Never?
More on topic is your claim that the Big Bang theory was rejected because of materialism. However, scientists are by nature conservative (not politically, but in their field). Plate techtonics was purposed in 1912 and wasn't accpeted until 50 years later!
The fact of the matter is that theories tend to take a long time to be accpeted- the exception being if the weight of evidence is overwheling or if there are no other theories available.
For example, evolution was accepted rather quickly, but it took over twenty years before they discarded Lamarkianism as a part of it.
As for the reason why the Big Bang theory was stalled, it was due to the fact that astronomers vastly underestimated the size of the universe and the opposing theory (steady state) seemed to be reasonable. Noticably, the scientific community embraced the Big Bang theory in 1964 due to evidence that the theory could account for and the steady state couldn't (backround radiation).
It is worth noting neither of the two theories had a materialistic bias- they both had matter coming out of nowhere into the universe. The steady state theory is actually MORE theistic- matter and galaxies suddenly appear and there is an edge that eliminates them... literally design.
The true conflict was between uniformitarianism and catastrophism- uniformitarianism being the default since geology showed that the world was sculpted by slow and gradual processes. Of course, accepting uniformitarianism is always correct leads to blind spots- Venus being an interesting example.
Darwin isn't a saint. Saints require miracles. You could say atheists venerate him... except as Gould has shown they don't. And naming something after a person isn't a sign of fanatical devotion- or are you going to say Americans love Columbus, Washington and Amerigo Vespuchi with fanatical adoration?
First, it is evolution.
Is the gene really the primary mechanism for evolution?
Yes. Genes have the genetic code which is inherited and hence the primary mechanism for evolution. This is rather new- DNA was only discovered in the fifties (RNA is used by some others in the same fashion).
Is a life-and-death struggle for scare resources really the main or only driving force for the production of new species?
No. That is what drives evolutionary change. Speciazation is generally driven by isolation.
Does the fossil record really reveal a history of slow, gradual changes?
See Gould. The science literally changes to match the evidence... a fact you take as a weakness.
You really have never studied the theory of evolution by natural selection have you? Why does a small population have sudden changes when cut off from the rest of its species? It is called the founder effect- when there are only a few individuals in a gene pool, there genes are overly represented in the desendant population. It has been observed repeatedly with humans.
Stop calling it "Darwinism". It is evolution and the theory has changed over the past 150 years. You seem to object to the fact that it has changed so that it fits the evidence more and more accurantly- except that is what science does. I don't see you objecting to "Newtonianism" because they have made the theory harder and harder to crack.
...And you seem just to have realized that living things have a structure called an omni box. Let me explain it to you- an omni box is a set of genes that controls the development of animals. It is part of the reason that animals took so long to evolve. And it is similar in all animal species, with only variations on a theme.
In addition certain genes can lie dormant if they lack an environmental trigger, but if given that rigger they activate. For example, if you don't get exposed to sunlight your melinan production drops. Interestingly enough there are some varieties of this that parents can pass on to their children- they are currently trying to discover how those work.
You do realize that if there were lizards who didn't have the necesary adaptation to eat the food they would die from starvation (aka survival of the fittest)?
Eugenists were progressives. They weren't small government- they actively pushed for government intervention. Where do you hear this nonsense?
The communists where extreme leftists- duh! As for refering to them as religious...
http://en.wikipedia.org/wiki/Lenin's_Mausoleum
http://en.wikipedia.org/wiki/Cult_of_personality
http://en.wikipedia.org/wiki/Kim_Il-sung
Most atheists considering being the leader of a country after you are dead because you are the anointed of heaven to be just a little bit religious.
For me it was the Eternal President of the Republic of Korea that tipped me off.
http://en.wikipedia.org/wiki/Eternal_President_of_the_Republic
Given the definition of religion as
A religion is a set of beliefs and practices, often centered upon specific supernatural and moral claims about reality, the cosmos, and human nature, and often codified as prayer, ritual, or religious law. Religion also encompasses ancestral or cultural traditions, writings, history, and mythology, as well as personal faith and religious experience. The term "religion" refers to both the personal practices related to communal faith and to group rituals and communication stemming from shared conviction.
North Korea definately fits.
Honestly, this is a strawman attacking the origional theory. What is next- gravity doesn't exist because its location is off (it actually is not where Newton's theory says it should be- Einstein provided the solution)?
Why does a small population have sudden changes when cut off from the rest of its species? It is called the founder effect
Sam, that's a theory, and probably true in some cases. This particular experiment with the lizards is trying to show that some perfectly normal lizards from one population evolved rapidly and not due to the founder effect. The original lizards were pretty average, and not genetic outliers. Therefore the cited experiment is trying to disprove that the founder's effect is the only source of rapid change within a species. If you believe that theories should be tested and that new evidence should change our existing theories then this experiment may be very important.
Of course the experiment might have been badly designed or have flaws. I can't get a copy of the actual materials and methods used. But on its face, this evidence persuasively attacks the notion that the founder's effect is the only reason for rapid speciation.
Stop calling it "Darwinism". It is evolution and the theory has changed over the past 150 years.
"Evolution" can refer to quite a few theories including the Neodarwinian synthesis, lamarkianism, lysenkoism, directed mutation, saltation etc. etc. Some may be true, some have been proved false. Some are still open for debate.
Darwin's theories, and the Neodarwinian synthesis based on it are one type of of evolutionary theory.
Tim seems to be asserting that there are flaws in Darwin's theory in specific and those who support Darwin's theories (or the neodarwinian synthesis), such as Dawkins, seem to be sticking by Darwin's view of things rather than changing their minds about what evolution really looks like. In particular, Neodarwinian theory asserts that creatures evolve via gradualism. Tim is citing this experiment to call gradualism into question.
He is not attacking 'evolution.' He is attacking those people who believe that Darwin accurately described evolution.
In addition certain genes can lie dormant if they lack an environmental trigger, but if given that rigger they activate.
It is possible for certain genes not to be expressed because of environmental factors as you describe, certainly. But the point is that the lizards seem to have changed their skeletal structure, and the changes are heretible, and not 'triggered' by the environment. Some of the changes, anyways.
In addition to the model you describe, it's also possible for some genes to be actively repressed regardless of most environmental factors.
The study of that process of genetic repression is called epigenetics. It deals with the methylation of DNA which causes the 'turning off' of genes which are still inherited though not expressed. It allows animals to rapidly (in few dozen generations) revert to phenotypes which their ancestors had expressed. It is a kind of genetic 'memory.' Vestigial legs on whales seem to be one example of this repression.
Tim is also supporting a theory about how limbs evolved in animals that I'm not really informed enough to discuss but which also seems to argue against Darwinian gradualism.
Another problem with the Neodarwinian synthesis that Tim didn't explicitly refer to is that mutations are not totally random, as had been assumed. (There is some evidence that we should remove the 'random' from "random variation and natural selection.")
What is next- gravity doesn't exist because its location is off
Tim is not arguing against evolution in general or in favor of some kind of short-earth creationism. I know, from reading other things he's written, that he believes creatures did evolve via some kind of process. He's arguing, specifically, against the Darwinian attempt to explain how evolution occurs.
This particular experiment with the lizards is trying to show that some perfectly normal lizards from one population evolved rapidly and not due to the founder effect.
I probably could have phrased that more precisely.
Gould said
Selective pressures are usually intense because peripheries mark the edge of ecological tolerance for ancestral forms.
Likewise, the Founder effect is commonly used to account for rapid changes in genetic frequency in small, isolated populations;
In a small sample, the frequencies of the genes may differ from the parental population. Isolated populations often have exceptionally high frequencies of otherwise rare alleles, and the most likely explanation is that the founding population had a disproportionate number of those rare alleles. The frequency of Huntington's disease in South Africa is a good example of this.
link
However in this case we're not talking about a few abnormal individuals who founded a new population because they were better adapted to it. Rather, we are looking at a few very representative specimens. And granted, small populations are noted for evolving more quickly. But previously, few people would have predicted such quick changes.
The steady state theory is actually MORE theistic- matter and galaxies suddenly appear and there is an edge that eliminates them... literally design.
The question here is not whether steady state appears "more theistic" in your view after the fact, but whether proportionally more theists or atheists were drawn to it, relative to other theories, before the question was resolved.
What does it indicate if you have theists pushing for what you describe as 'less theistic' theories and atheists pushing for what you describe as 'more theistic' theories?
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Looked back at the article for an indepth analysis. Your getting sloppy Ryan- you didn't read it either. If you did, you would have torn me for not paying attention.
Here are the relevant points:
- DNA was the same as the source (NOT evolutionary CHANGE)
- Diet differance
- Bigger bite
- Value thingees.
- Population and diet.
2 and 5 are obvious- food was plentiful so they switched to a differant source.
1 is important- the changes weren't genetic. So what could it be? Environmental factors. For the jaw, I believe that it is determined by its usage- the more used, the better it gets. Sort of like how muscles grow with practice.
The valve I have no clue. It is useful for grasses and the origional population doesn't eat grasses, so they don't use it.
They aren't complex- just extra chambers. However the interesting thing is the bacteria in the gut. How did the lizards body encourage nematodes to proliferate? That is a good question- I don't know.
Obviously, this will require lizard dissection and lizard DNA recording. What? I don't have answers, ut I see no reason not to consider this reponce to environmental factors.
The article didn't say they where passed on- so it could be that. Or it could be where the DNA gets markets and instructions that get passed on.
Anyway this isn't saltations- there is no new species. Sorry Tim!
Big Bang was made by a preist and the steady state was made by people who didn't like the theistic interpretations. True. It doesn't change the fact that the Big Bang has only one inexplicable part (which can be explained as only being inexplicable because it only happened once) vs. Steady State which requires constant maintainence.
So the Steady State and the attempt to eliminate negative numbers (funny story behind this one) are both the fault of people trying to comform reality to their presuppositions, and not the other way around... unless you are Hindu, in which case the Big Bang is the atheistic theory.
It is worth noting that when the evidence was in, the agreed they were wrong... well, the community at least. The background microwave radiation was the nail in the coffin. There is a new SST called QSS which is exactly what I lambasted as being theistic.
Of course, the newest version sidesteps creation with a model that is closed.
Note that it DIDN'T halt the search for answers. The opponents tried to find fault, but they didn't ban it or eliminate it- the worst they did was mock it. So it is hardly the sort of "fanaticism" that Tim describes.
Or, to sum it up, there was no evolution involved at all, nor any speciazation. Opps- you dropped the ball on this one Tim.
Your getting sloppy Ryan- you didn't read it either. If you did, you would have torn me for not paying attention.
Did you read my reply to Tim above yours? I already addressed some of your points. What's the use of retyping them?
Actually, I did read the article and a number of other posts about this topic as well.
The problem is, it's hard to get solid information on what went on here. The peer reviewed submission
to the scientific journal isn't available for free. So I'm left with second hand information, including claims (possibly false) from other sites that the lizard's changes were, in fact, heretible.
- DNA was the same as the source (NOT evolutionary CHANGE)
It's a huge amount of work to sequence the genome of an entire organism. So I'm betting dollars to donuts they didn't compare the experimental and control genomes base by base. What would typically
happen is that you would compare a few loci from the DNA of one animal and another. A match on even 5 out of
six loci would confirm that the two lizards were the same species.
Given the circumstances, experimental error seems a possibility, though.
It's difficult to debate the other points, as I mentioned, because I can't get a copy of the original experiment, just a bunch of write-ups in pop-science blogs and so on, which aren't really reliable. I've already said that we need to see how many changes persist once the lizards are forced back onto an all-insect diet.
Anyway this isn't saltations- there is no new species. Sorry Tim!
Saltation just requires rapid change from one generation to the next. Not new species. If the changes are in fact inherited from generation to generation then this does seem to be a good example of saltation.
The various pop-sci articles might be misleading, or they might be accurate. It's hard to tell. My concern was that you seemed to be missing the points that Tim was making altogether, for instance; you assumed that Darwinism and Evolution were synonymous and an attack on the first was an attack on the second.
Your assertion; In addition certain genes can lie dormant if they lack an environmental trigger, but if given that rigger they activate.
Is a possible explanation, but leaves open the question; why didn't the lizards show these new traits in their first few generations on the island? Something changed over time. Either their (hereditary) behavior or their physiology or both. It seems impossible to resolve these points with the evidence we have access to. I was just concerned that you weren't even addressing the points that Tim was making.
DNA was the same as the source (NOT evolutionary CHANGE)
Actually, you could entirely conserve an organism's DNA but make epigenetic changes and that would change the phenotype and possibly be heretible. If heretible, that would still be considered 'evolution' by just about any standard.
It's worth noting that Darwin postulated evolution before the existence of genes was properly understood, and Mendel's experiments were lost for quite some time after they were first made. So changes in DNA are not required by Darwin's original theory. Only inherited variations are required.
Check out the wikipedia article on epigenetics for what I'm talking about. A few epigenetic changes are actually inherited.
It is hard to sequence, NOT to compare DNA. That is rather simple- you just see how well the two sets of strands match up.
Of course, for small changes that method doesn't work, but they do have others.
Also, arguing from imformation where you "Fill in the gaps"... not really reliable.
I think the first few generations did change.
Essentially you are guessing because of incomplete info. Or you could wait for more complete info- it isn't like this is a state secret. Eventually it will enter the public domain.
It is hard to sequence, NOT to compare DNA. That is rather simple- you just see how well the two sets of strands match up.
Do you mean how well they anneal? Not sure what specific process you're referring to here.
Of course, for small changes that method doesn't work,
Of course. And for epigenetic changes it will also not work. Which is why it's not particularly relevant, except possibly to show that the two lizard species didn't, in fact, interbreed with some other species.
Essentially you are guessing because of incomplete info.
Not sure who "you" is, but yes. I've said several times, there's a limit to how deep we can analyze this because of our limited info. You're also guessing because of incomplete info. Is that a bad thing to do?
That said, there's been a ton of emerging evidence that variations in a population aren't just about random changes to particular genes. This isn't an isolated observation. And this evidence, in that context, would seem to tentatively support that view.
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Even the Operating System which I am using to write this was named in his honor.
And it competed with Windows XP, which Microsoft internally named "Cairo" prior to release.
Posted by: Ryan W. on July 15, 2008 10:53 PM