Italian wall lizards placed on a tiny island in the Adriatic Sea evolved over three decades to adapt to their surroundings.
Posted on 06/03/2008 2:33:27 PM PDT by Incorrigible
Italian wall lizards placed on a tiny island in the Adriatic Sea evolved over three decades to adapt to their surroundings. |
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AMHERST, Mass. — In 1971, five pairs of Italian wall lizards were transplanted by biologists from their home island of Pod Kopiste, in the South Adriatic Sea, to the neighboring but subtly different island of Pod Mrcaru, where none lived, as an experiment in evolution.
How, if at all, would these creatures change?
Largely insect eaters, the half-foot long reptiles would find themselves on an island where insects were in short supply but plants were not.
Because of political upheaval in the region — the Adriatic Sea borders Croatia — it was not until 2004 that Duncan Irschick, a professor of biology at the University of Massachusetts, and a team of international biologists could return to find out what had happened to the lizards.
"As a scientist, it was a once in a lifetime opportunity. Historical circumstances prevented people from going back to the island for a very long time," he said. "So when we first went out there in 2004, we didn't know what we would find. We chartered a boat out to the island, and it was amazing. It was swarming with lizards."
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.
They found on that visit and subsequent trips in 2005 and 2006 that the wall lizards had changed dramatically in the intervening decades. Results of their study were published March 25 in the "Proceedings of the National Academy of Sciences."
Two of the most striking changes were the increase in head size and the change in head shape.
"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," Irschick 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.
Most importantly, though, the researchers discovered the digestive tracts of the lizards had changed. They were now divided, creating a fermentation chamber where microbes could break down the toughest portions of the plants.
"What was unique about this study was that the lizards developed brand new structures, a part of their gut called a 'cecal valve' (which separates the chambers). No one had ever documented that kind of change before," Irschick said.
"It's good evidence that not only can evolution happen rapidly, but animals can evolve new structures as well (in a short time span)," he said.
To confirm that the lizards were descendants of the 10 individuals introduced to the island, the researchers conducted a DNA analysis and found they were genetically identical to the original ones.
The research was supported by the National Science Foundation and the Fund for Scientific Research in Flanders. Additional members of the study team included researchers from Harvard University, University of Antwerp, the Royal Belgian Institute of Natural Sciences and the Croatian Natural History Museum.
(Stan Freeman is a staff writer for The Republican of Springfield, Mass. He can be contacted at sfreeman(at)repub.com.)
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What exactly does the term "species" mean, given that from what I understand the conventional definition doesn't form an equivalence relation (which would mean that if A and B are the same species, and B and C are the same species, A and C would have to likewise be the same species)?
For that matter, why is there any need to argue that nothing resembling evolution happened at all? The story of the Flood doesn't work unless some new species or subspecies appeared in Post-diluvian times. While evolution would not have to be the mechanism for such appearances, I see no reason to favor any other theory.
When you see that adaptive change can occur that quickly, how can you claim that speciation is impossible?
“... the researchers conducted a DNA analysis and found they were genetically identical to the original ones.” What part of “genetically identical” did you not understand?
Indeed. I've read a few chapters; don't agree with all of it, but agree it's fascinating.
There seems to be an overly strong regard for certain things like the 'days' of creation. Given that the term 'day' has no natural global meaning, and given that the term has no particularly logical meaning in the absence of the Sun, I see no reason to attach anything resembling the modern '24 hour' meaning to the term.
Further, the argument for 'Intelligent Design' seems to be, essentially, "There's all this cool stuff; it couldn't have happened by accident. Therefore, it must have been created by a god--presumably the one we worship." I would counter that it would be much more reasonable to say, "There's all this cool stuff; even taking into account the huge selection bias that we're only looking at a planet with enough biodiversity to include us, it's unlikely that all the cool stuff happened by change; it was most likely formed or manipulated by some entity we do not understand, though the nature of such entity is unknown." There are a lot of theories that have been proposed, with varying degrees of seriousness, involving other planets and galaxies in the formation of this one. Some theories are atheistic (e.g. life was created by physically-existing creatures from another galaxy); some involve creative Biblical interpretation (the Ark was really a space ship). While many of the theories aren't very well falsifiable, the fact that they would be plausible renders the 'it can't have been anything other than a god' argument ineffective.
BTW, when the article talks about “Y chromosome Adam”, why not “Y chromosome Noah”? Is not he the progenitor of all post-diluvian people?
Google epigenetics.
Here the lizards share the same DNA, and are yet so different. They look fifferent, so they must be a different species, yet they are not. Look at how short a time these changes took place. Yet evolutionists claim the earth to be billions of years old, and that we evolved over millions of years. Positively untrue. How can I claim it impossible? Because the Bible told me so, and because the only real eidence ever found tends to agree with me.
If you rely on the bible for your evidence you have no business opining in the various fields of science.
Science relies on evidence, and no amount of scientific evidence will change your mind. You are not doing science, so why don't you just leave it well enough alone?
Lounge Lizards usually make serious adaptive changes when last call is announced.
So you are using the tired old argument that people with Christian faith cannot possibly be scientists? Really? Take a look at your scientific history, there aren’t too many who did not have faith in God. The hostile atheist takeover of the sciences is a modern phenomenon. And you have just as much faith as I do, don’t act like you don’t.
How many generations in less than 50 years? Not enough to evolve major somatic differences. If this report is true, it tends to prove that there is something more than evolution going on. Dr. Lamarck, paging Dr. Lamarck.
Why not look into the claims and then poo poo it?
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