Lizards Undergo Rapid Evolution After Introduction To A New Home (4/19/2008)
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.
|Pod Mrcaru lizard. (Credit: Anthony Herrel of the University of Antwerp)|
"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."
Researchers returned to the islands twice a year for three years, in the spring and summer of 2004, 2005 and 2006. Captured lizards were transported to a field laboratory and measured for snout-vent length, head dimensions and body mass. Tail clips taken for DNA analysis confirmed that the Pod Mrcaru lizards were genetically identical to the source population on Pod Kopiste.
Observed changes in head morphology were caused by adaptation to a different food source. According to Irschick, lizards on the barren island of Pod Kopiste were well-suited to catching mobile prey, feasting mainly on insects. Life on Pod Mrcaru, where they had never lived before, offered them an abundant supply of plant foods, including the leaves and stems from native shrubs. Analysis of the stomach contents of lizards on Pod Mrcaru showed that their diet included up to two-thirds plants, depending on the season, a large increase over the population of Pod Kopiste.
"As a result, individuals on Pod Mrcaru have heads that are longer, wider and taller than those on Pod Kopiste, which translates into a big increase in bite force," says Irschick. "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."
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. Cecal valve evolution probably went hand-in-hand with a novel association between the lizards on Pod Mrcaru and microorganisms called nematodes that break down cellulose, which were found in their hindguts."
Change in diet also affected the population density and social structure of the Pod Mrcaru population. 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.
"What is unique about this finding is that rapid evolution can affect not only the structure and function of a species, but also influence behavioral ecology and natural history," says Irschick.
Results of the study were published March 25 in Proceedings of the National Academy of Sciences. This research was supported by the National Science Foundation and the Fund for Scientific Research in Flanders. Additional members of the research team include Anthony Herrel of Harvard University and the University of Antwerp, Kathleen Huyghe, Bieke Vanhooydonck, Thierry Backeljau and Raoul Van Damme of the University of Antwerp, Karin Breugelmans of the Royal Belgian Institute of Natural Sciences and Irena Grbac of the Croatian Natural History Museum.
Note: This story has been adapted from a news release issued by the University Of Massachusetts, Amherst
4/19/2008 8:14:06 PM MST
4/19/2008 8:59:53 PM MST
"LAME" commenter is obviously a trembling "bible-thumper" who realizes what this discovery means to his book of fairy tales AKA "the bible"... now that's lame!
4/19/2008 9:06:41 PM MST
Christopher obviously a trembling ID fighting, ideological Nazi.
4/19/2008 9:43:00 PM MST
Hey, go easy on him. Anyone who thinks a sexually-reproducing organism is "genetically identical" to its cousins doesn't know the first thing about biology.
4/19/2008 9:55:07 PM MST
Think of it as evolution in action.
4/19/2008 9:59:57 PM MST
I agree with Christopher, watch this thread to see more "christians" resort to name-calling and references to their fictional bible stories to hold onto the last grasp of their ancient way of thinking in an advancing society full of free-thinking, educated, humanists(look that term up in Wikipedia for a real education).
4/19/2008 10:06:53 PM MST
Adaptation, yes and this has been demostrated on many occasions. But I'm afraid you are kidding yourself if you think this is evolution. No biologist in their right mind would claim this is a different species which is what you must do in order to claim evolution.
The statement 'genetically identical' is indeed incorrect, but there is nothing here at all to validate evolution.
Jon, think of it as a hand wave with no scientific mertit.
4/19/2008 10:16:02 PM MST
Sara, do you mean like Ian did, calling Christopher a Nazi??? Here we are in the 21st century calling anyone who thinks for themselves and doesn't hold onto to 1000 year old stories as their sole guide to life a nazi, wow! Wake up people!!!
4/19/2008 10:29:47 PM MST
Bishop, by the way, the definition of evolve is:
to develop gradually, especially from a simple to a more complex form.
This id what the lizard did. You religious weirdos and your shifty redefining semantics, adaptation means they find a new way to survive without changing physically, evolution means their bodies change to be able to accomplish this new survival mechanism.
So no matter how loud you trumpet your horn "Bishop", you're kind is a dying breed. So long to the wars over religion too, maybe when others mature and leave behind the crutch of religion we may all live in peace.
4/19/2008 10:30:19 PM MST
"I'm afraid you are kidding yourself if you think this is evolution"
If this isn't evolution by means of natural selection (albeit small scale... it was only 36 years for crying out loud!), then what is?
4/19/2008 10:30:44 PM MST
I don't even dignify Creationists/ID-ists with a response. Evolution is a fact, even if we don't know all the details. If you want to be left behind, feel free.
4/19/2008 10:35:51 PM MST
Adaptation and evolution are two different things. Doesn't prove / disprove anything.
FWIW you don't have to not believe in Evolution to believe in Jesus. I don't think He ever made that a condition of salvation ..but hardly the point here.
What I want to know is if any of those who believed their evolutionary oriented high school propaganda can tell me how evolution proceeds from an organism with say 24 pairs of chromosomes to one with say 25. You can't like gradually evolve from 24 to 25. It has to be the mother has 24 and the offspring has 25. I can see a mechanism for a mutation being born with 25 pairs, but what does it mate with? AFAIK these kinds of mutations are never fertile. Evolution is a wonderful theory, but there is no experimental or observed evidence of it ever happening...the evidence is entirely empirical, although the empirical case is extremely powerful. You might want to stop and ask why you blindly accept your high school biology teachers world view without question though.
just a ( rambling ) thought ( or two )
4/19/2008 10:59:20 PM MST
CAL wrote: "If this isn't evolution by means of natural selection (albeit small scale... it was only 36 years for crying out loud!), then what is?"
This is adaptation, there was too little time/generations for evolution to take place. Ofcourse, the abillity for adaptation evolved as the lizards in the past lived in different kinds of environments, and that got encoded in their genetic history.
4/19/2008 11:01:00 PM MST
Information present in the genome can increases though a gene or chromosome being copied more then once. This is sometimes fatal but when it's not there are then two sections of DNA doing the same thing. This removes selective pressure from the duplicates because its job is already being done. Genetic drift causes it to change. This adds new material to the genome. This has been observed in the lab and in nature. For a good example of this look at how the spider monkey acquired full color vision.
4/19/2008 11:07:43 PM MST
Adaption is what occurs during an organism's lifetime. This is a Change in allele frequency, evolution on a small scale.
4/20/2008 1:34:11 AM MST
"You might want to stop and ask why you blindly accept your high school biology teachers world view without question though."
Its a two way street.
4/20/2008 2:15:51 AM MST
@TimeTraveller: please see http://en.wikipedia.org/wiki/Triple_X_syndrome
4/20/2008 3:02:06 AM MST
Thank god I'm an atheist!
4/20/2008 4:38:22 AM MST
Evolution is like a movie and an adaptation is like a transition from one frame to another. As the Chinese proverb would go, if I'd written it: "A thousand-kilometer journey consists of one-meter steps."
4/20/2008 8:46:43 AM MST
What is sad and much too apparent here is that there are two opposing sides equally intransigent and too eager to interpret any discovery as reinforcing their respective positions without thought or understanding. Shame on the 'science' side here. You should know better if you really understand science.
4/20/2008 9:56:45 AM MST
These revisionists, these deniers. They can look evolution straight in the eye and pretend is isn't there.
Let's break this down. Evolution: change in allele frequency over time. This article: changes in lizards due to change in allele frequency over time. Conclusion: evolution has been observed.
There is no way to say otherwise and claim it is based on science or evidence or logic. Evolution: Fact. Period, end of sentence, end of paragraph, close book, put it on the shelf marked "Shelf full of books containing facts."
4/20/2008 10:31:01 AM MST
MW is right: evolution is defined as change in allele frequency over time. if subsequent generations exhibit the same adaptations as their parents, then obviously some genes are being handed down...whether the creatures speciate (become different species) or not depends on whether they can still breed with the original stock and have viable offspring.. i think that's against some research ethics, but hey i'd like to see that.
IRregardless, evolution happens, and this is a case in point. ignorance is never a substitution for the truth.
PS: people should know better that evolution is everywhere. look at the dog you have, or the one your neighbour is walking. find out just exactly how many of them are BRED to exhibit the traits they have... what humans can do, nature does casually over geological periods of time.
4/20/2008 10:51:31 AM MST
But aren't these lizards still, well, lizards? And dog breeding has created many shapes and sizes of dogs.. but aren't they still just dogs?
Will we see these lizards grow feathers and the ability to fly?
4/20/2008 9:06:31 PM MST
Silly people of coarse evolution is 'real'. What does that have to do with the existence of God? Evolution is just one aspect of the program that is the 'Matrix'.
4/21/2008 6:48:55 PM MST
Correct me if you believe I'm wrong, but isn't science 'truly' about observing events and discovering the logic/patterns/math behind those events? If that is the case, what are the science people here doing to bring shame other than following the study?
Isn't the vast majority of peer reviewed science (which this article is based upon) required to be double-blind and seconded before being accepted? If that is the cast, where is this shame coming from?
I'm sorry, but I fail to see how people who don't blind themselves to reality are the ones doing the harm.
4/22/2008 12:39:50 AM MST
Sudo... was that sarcasm? I hope so, because if not then you might want to learn how evolution works
4/22/2008 1:32:41 AM MST
Haven't any of the naysayers who clutch so desperately to their book of lies ever watched Zeitgeist? Christianity is a direct plagiarism of Egyptian mythology and nothing more than a politically motivated "creation". History, not science, has provided plenty of convincing evidence to discredit the God-myth. Save your Sundays for football...
4/22/2008 10:15:45 AM MST
Theoretically, they could. But that would take a long time, far more than we are willing to commit to observing them (ie, quite a bit more than a human lifetime).
And yes, they are still lizards, most likely still of the same species of lizards. They have simply evolved to fit this new environment they live in. (Just like humans came up with different skin pigmentation depending on where in the world you live)
In short: Evolution is all about survival. If it helps you survive, it gets passed on to your children. If it is harmful, it will most likely not (unless it's something that generally kick in AFTER reproduction, see Alzheimer's in humans).
||OH god Kill Me Now|
4/22/2008 10:35:01 AM MST
... so i don't have to watch more religious blind-folded people fall to even lower depths of ignorance.
It is in your face and you still look the other way... even a god should just bitch-slap you for being stupid.
4/22/2008 12:10:28 PM MST
Evolution isn't something that can be ignored. Its as real as your hand, and to deny it is to live in ignorance. I believe in evolution but i also believe in god. I found my balance, but i do not believe people rode on the backs of dinosaurs. That is ridiculous!! Its hard to explain my view on life, but I can say that evolution is very real. Although these lizards haven't changed that much, its still true that they HAVE changed, therefore evolution has taken place. Closed minded views on this topic really annoy me.....
4/22/2008 4:41:00 PM MST
I noted that there are a few comments which need to be addressed. My personal background is MD, biochemist and son of a preacher (reformed to evolutionist)
- There are several proven multi-cellular speciation events. Just look them up.
- The comments about increasing or decreasing number of chromosomes. There are plenty of humans, let alone other species around which survive and reproduce within the same species with different chromosomes. Please see "the murderers chromosome" and "super-femmales" aka XYY and XXX.
- also, there are several translocation events which can occur. One of the major ones is the one which occurred in "Adam" a protochimp/protohuman. This is a temporally and physically located Robertsonian translocation which "glued" 2 chromosomes at the centromere and reduced the visible pair number of chromosomes from the chimps 24 to the humans 23.
4/23/2008 10:00:23 AM MST
Actually i must correct you the bible was copied from mesitopian and babalonian (forgive the spelling) religon,
and to all the idiots out there,
evolution = fact,
even major spiritual leaders from the pope to the dali lami accept it,
even the jews accept it and its there core religous text that has been PROVED! untrue or at least metaphorical.
the whole civilized world accept it apart from creationist(mostly american) so stop making the same stupid arguments and open your ears and minds to whats really true EVOLUTION!..
4/23/2008 11:10:39 PM MST
Well, this study does offer indisputable and very much irrefutable evidence of evolution. The study does this but don't forget that that fact is the very vaguest of any viable synopsis of information available regarding this incredible scientific revelation. And yes, science does see it's own form of revelation every blue moon.
This case of lizards evolving in 36 years time... a marvel of nature in the eyes of science. It shows that mankind has so much more to learn and discover in regards to the topic of life itself.
Here's to breaking new ground, or at least a broadening of prospective.
4/24/2008 12:11:15 PM MST
The Lord works in wonderful ways. Isn't is miraculous how He provides for the lizards in different areas? It is the work of an all-powerful and benevolent God truly. Praise His Holy name!
4/24/2008 5:59:19 PM MST
So, given this experiment, I want to try one of my own. How about I take a human who grew up eating very little meat. I then put them in a place that has lots of meat. Over 36 years, I will likely see that they gain a lot of weight. Would I then be able to say that I have shown evolution/adaptation in humans?
When discussing evolution, please make the distinction between micro and macro evolution. Micro evolution is change within a species and has been proven many times. This is what many of the above posters are calling change in allele frequency. There are many experiments that vary, but they are similar to Darwin's original Galápagos Islands study. By the way, this study does not actually talk about change in allele frequency - the two groups were genetically identical.
Macro evolution is change between species. This is not addressed at all in this study. This is the area that people constantly debate. There is less proof for macro evolution. The distinction is very important as they are very different. Lumping them together and using micro to prove macro is a slight of hand that I find many evolutionists playing.
4/25/2008 11:15:39 AM MST
Although it is obvious that micro evolution is taking place (the changing size etc..), the fact that the lizards developed the new cecal valves structures can only be taken as macro evolution.
Micro evolution is the changing of whats already there, but to develope something new, structures that only "occur in less than 1 percent of all known species of scaled reptiles," is macro and thus true proof of Darwins theory.
4/25/2008 11:14:06 PM MST
Fact 1: Evolution is real, it can not be denied.
Fact 2: Humans have lived on this Earth more then the supposed 10,000 years the bible and religion states.
Fact 3: The Bible is full of contradictions that completely nullify any validity that it could have ever had. It's a book of moral teaching based in no facts that actually happened. It's credibility is 0, utterly devoid of facts.
Fact 4: Religion is losing its momentum and will die out within a century. I call this societal evolution, we don't need it anymore. The Romans needed it at the time but now we don't and I say good riddance.
4/28/2008 7:38:42 AM MST
I'd like to see any mention of genetics in this article before I was willing to accept this as true evolution. I agree the phenotypical evidence points to evolution, but without the genotypical discussion, this example can't be called evolution yet.
4/28/2008 5:29:59 PM MST
I find it humorous, though sad, that apparently no-one has understood the import of the first post, by LAME, "genetically identical."
Everyone please re-read the third paragraph. Quote: "Tail clips taken for DNA analysis confirmed that the Pod Mrcaru lizards were genetically identical to the source population on Pod Kopiste."
As for myself, I have no idea what this is supposed to mean, as it seems to be non-sensical, assuming they reproduce sexually. It might mean that the person who wrote the article had an imperfect understanding of the subject. I believe LAME was pointing this fact out; I don't think he is necessarily creationist. I certainly am not.
4/29/2008 8:58:31 AM MST
Exactly Jeff! It's amazing that a whole creationism vs. evolution debate can be triggered this easily.
Back to the topic, I think the author meant to say that the genetic analysis confirmed that Pod Mrcaru descended from Pod Kopiste and were not a completely unrelated species which evolved independently.
Of course, if they really were genetically identical, no evolution would be possible.
4/29/2008 1:54:31 PM MST
"Of course, if they really were genetically identical, no evolution would be possible."
If they really were genetically identical, no REPRODUCTION would be possible.
4/29/2008 8:23:52 PM MST
Jim, organisms can reproduce regardless of if they are genetically identical. An organism self-fertilizing itself (common in plants) or bacteria's asexual reproduction is essentially genetically identical reproduction, it produces clones.
Now, two lizards much less two populations of lizards are not going to be genetically identical, unless they were identical twins, which I doubt even happens in lizards. Author probably means they have a very recent common ancestor
5/10/2008 10:15:32 PM MST
You can believe in evolution and be a christian.
You dont have to believe that people came from monkeys so realize that evolution is possible.
just food for thought.
5/11/2008 7:34:10 AM MST
After reading the comments to this post I'm amazed.
From nowhere rises the everlasting evolution vs creation debate, and everyone are telling the other side to open their eyes. Both sides having their eyes completely shut for their own logical mistakes.
Most annoying i find "the mentalis" statement #3 about the Bible being full of contradiction. Many have tried to point them out, but so far I haven't seen any of them.
Fact #4 about religion losing its momentum is also annoying me, studies say that Christianity in the civilized world is loosing its grip, but then again buddhism and other religions are becoming even more popular.
Just a few thoughts from a silly young man who doesn't believe in proving where we came from.
5/13/2008 2:26:10 AM MST
You have mistaken. People did not evolve from monkeys. They ARE monkeys!
5/13/2008 12:06:59 PM MST
QUOTE: "Most annoying i find "the mentalis" statement #3 about the Bible being full of contradiction. Many have tried to point them out, but so far I haven't seen any of them."
Have you actually ever read a bible? There are often not only contradictions, but even further, contradictions of the contradictions! I can speak for many people to say that if it were so easy to poke holes in the proofs of science, it would be thrown out.
As far as never seeing any, here, have a website chock full of them:
5/16/2008 8:48:51 AM MST
I don't like how this article only tells us that the evolutionary change was over a certain amount of years.
When it comes to evolution, all that really matters is generations. I wonder how many of those it took to make these better adapted lizards.
I find it difficult to swallow this article without more evidence.
5/16/2008 9:13:58 AM MST
The title was "Lizards Undergo Rapid Evolution", yet; I failed to see the gene evidence presented in this article. This is important if one is demonstrating evidence of evolution. This is just an adaptation similar to what happens when a skinny family in Mexico move to the United States. Their decedents are much bigger and need a few generations to adapt to a new way of plentiful life. They were human then and continue to be human later. If the above mentioned lizard were returned to its own environment it would put away its new tools and revert to the original state and still be made of the same DNA. Yes, call me a Bible thumper if you wish, but a truly scientific mind will understand what I am saying.
5/18/2008 6:31:59 PM MST
Evolution and Adaptation go hand in hand. Evolution from one species to another is the result of multiple compounding adaptations that eventually create an entirely new species over a long period of time. I bet if you gave these two lizard populations a few hundred thousand years you'd find two completely different species.
5/24/2008 11:26:39 PM MST
wow i love how people hate on each other because of their beliefs
so many people are like "wow, you believe in god and not evolution you must be stupid or something"
is that necessary who are you to decide what someone believes in and why do you even care? if you believe evolution is right then great for you but not everyone does so accept that
my thoughts are, i believe evolution is completely possible but at the same time there have been strange coincidences from the bible,, (for example chernobyl, how it was prophesized in revelations) and if you are christian but there is no god then you meet the same fate as everyone else but if there is a god then at least you wont be burning your ass off in hell (as the bible says will happen in hell)
5/24/2008 11:44:34 PM MST
"Have you actually ever read a bible? There are often not only contradictions, but even further, contradictions of the contradictions! I can speak for many people to say that if it were so easy to poke holes in the proofs of science, it would be thrown out.
As far as never seeing any, here, have a website chock full of them:
wow that bible contradictions site isnt even legit but nice try buddy i checked them myself
its all just passages from the bible that dont make sense unless you read the whole part, not just the part they cut off
also, they have alot of typing errors idk if they were intentional to make the bible seem so wrong
i really dont understand why people do this they just try to make themselves look better by putting someone else down, completely ignoring their thoughts
why dont u try reading the bible for once, it could teach you something more than just shutting yourself up to your THEORY of evoultion
dont try to win an argument when you dont know both sides of the story
||ok one more thing|
5/25/2008 12:02:19 AM MST
one more thing to say about that contradiction website
the person who came up with all those contradictions sounds like a 10 year old no offense
"well he said this, well he said that," he finds the most meaningless contradictions
one of them, "snails dont melt" what is the significance in that? does anyone really care if they melt or not? maybe "evolution" changed snails
also, many of them are just from poor understanding of the text whoever wrote those contradictions clearly did not understand one word of the bible and did not get the big picture
he doesnt understand what the bible is saying so he assumes
he assumes some passages refer to things they dont
assumptions are not an excuse for failure to understand.
7/25/2008 4:12:49 AM MST
You're all wrong- actually the most annoying thing about these comments are that people claim to be knowledgeable though they can barely spell. Finish high-school first, argue scientific points later.
By the way, "double-blind" is only applicable to human subjects. What would be the point of performing double-blind tests on lizards? So that the lizards wouldn't know which ones were getting experimental treatment? Jesus christ already, why do people even get mixed up in a debate when they have NO clue what they're talking about?
9/22/2008 1:24:14 AM MST
"..designed to slow the passage of food by creating fermentation chambers in the gut"
I just find this statement interesting.
11/2/2008 10:20:48 AM MST
"designed" was probably a poor choice of words.
"the purpose of" would be a better phrase.
The fact that they used "designed" is more due to the informal nature of the article, and that, as humans, we tend to call things designed since that's what we do.
And for all the people who keep making these false arguments for creationism, think about this - Why do you think there is no objective (read: scientific) proof FOR creationism? All your "proof" is either bible quotes, which are not scientific, or they are arguments AGAINST evolution, almost all of which are wrong when actually put up against the facts. (I would say all are wrong, but I'm not as informed as to all of their arguments and there may be one with a shred of fact to it, but none that I've seen yet, and one fact can't destroy the mountain of factual evidence for evolution).
All I can say is put up or shut up. Give actual, provable, scientific evidence FOR intelligent design/creaton, or stop trying to say it's science.
6/2/2009 4:08:22 AM MST
Please don't say Macro and Microevolution are totally different. They are not.
They are just descriptions of the same process, i.e. evolution. You can view macroevolution as lots of micro-evolution (+ environment).
Also defining when two closely related animals/plants are different species can be a tricky thing.
If you "believe" in microevolution but not macroevolution, please tell us, what is the mechanism that stops microevolution progressing to the point of macro!?
Are you suggesting...
a. That the lizards can't evolve to the point they can't breed with their close cousins on neighbouring islands?
b. the anti-evolution fairy stops the process somehow?
FYI. Even twins are now thought not to always be genetically identical. Please explain how these lizards are genetically identical? Have they been perfectly cloned? Please, please explain. Oh, wait. Is it that you just don't have a clue?
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