Skip to comments.Looks Can Be Deceiving: Lizards acquire same camouflaging adaptation in different ways
Posted on 01/04/2010 12:23:53 PM PST by null and void
Does it matter if nature solves the same problem multiple ways? A NSF-supported study of lizard populations in White Sands, NM, has helped researcher Erica Rosenblum of the University of Idaho begin to answer that question. Published December 28 in the Proceedings of the National Academy of Sciences, the article describes genetic differences between lizards found in habitats that contain white or dark soils. These stark differences in color are an ideal environment to study natural selection and gene flow.
Lizard species that exhibit rapid adaptation to White Sands, NM. Courtesy of Erica Bree Rosenblum, University of Idaho
In three separate lizard species, Rosenblum and her team identified mutations in the gene encoding the melanocortin-1 receptor (Mc1r), all resulting in lizards with light skin. Further biochemical characterization of the mutations revealed that, although the same gene is affected in two of the species, the functional changes caused by the mutations were distinct. In one species, the receptor is in the wrong location in the cell, while in a different species, the receptor is in the correct location, but it is unable to transmit signal.
"The mutations we observed resulted in two distinct changes in how the Mc1 receptor functioned. Mc1r acts like a light switch for melanin, so even though the way the signaling is disrupted is different, outwardly we see the same result: light-skinned lizards," Rosenblum explained.
Although the end point, light skin, is the same, the different ways the reptiles achieve this have important implications for gene flow in each species. For instance, the dominance pattern of the mutated genes is different in the two species. The mutation that results in improperly located Mc1r protein is dominant, meaning it takes only one copy of the new gene to result in light-skinned lizards. In contrast, the lizards that appear white due to faulty receptor signal transmission must harbor two copies of the mutant gene because the trait is recessive.
Rosenblum added, "There is preliminary evidence that suggests the genes involved in adaptation can also affect speciation. Changes in melanin affect coloration on the top of the body, which predators see, and also the sides of the body, which other lizards use to decide who to mate with. Therefore, both natural selection and sexual selection appear to play a role in this system."
This habitat provides researchers the unique opportunity to observe natural selection and speciation in progress. New species can form relatively quickly (over a few thousand years) in some selection environments, but catching organisms in the act is rare. The more researchers understand the speciation process, the better equipped we will be to try to preserve this process as our landscape changes.
It’s true with chicks too,, appearances can deceive.
I smell racism in here, someplace.
Natural selection, yes.
Speciation in progress? How so?
New species can form relatively quickly (over a few thousand years) in some selection environments, but catching organisms in the act is rare.
The scientists seemed to have transitioned from "preliminary evidence" to a firm conclusion is about 1 paragraph.
Looks can be deceiving?..................
RINOs do this all the time. act and look like coservatives when they need to get elected but afterwards revert to their true moderate skin. politicians are like the lizards in V.
I wasn’t aware there’s a subspecies of Cathartes aura.
“Rosenblum added, ‘There is preliminary evidence that suggests the genes involved in adaptation can also affect speciation.’”
This is exactly the kind of baseless conjecture that makes the evolutionary hypothesis unacceptable. This has nothing to do with “speciation.” There are no new species.
There are many we have yet to discover.
“There are many we have yet to discover.”
No doubt. But you know that was not my point, so way did you post this?
The point, since you apparently missed it, is there are no “new species” evolving from others that we do know.
Because there is so much more we have to learn about this planet, and the life on it.
To claim we know it all, about what can or cannot happen when we haven't even discovered all the possible life forms is a bit presumptuous.
The point, since you apparently missed it, is there are no new species evolving from others that we do know.
Maybe 'evolving' takes a much longer period of time than man has been studying 'evolving'.
Can you unequivocally prove that there has not been any new 'species' created since the creation of Earth?
“Can you unequivocally prove that there has not been any new ‘species’ created since the creation of Earth?”
First, the purpose of “proof” is not to convince others. Science is not a debating society. Proof is only a way of ensuring your reasoning (and experiments) are correct.
Secondly, I never said evolution is wrong or that there will never be evidence that verifies. I would not be the least bit disappointed if it were. At the moment, however, I’m totally unconvinced and cannot embrace it. The fact that evolutionists themselves use so many “unscientific” methods to shore it up, so to speak, just like the global-warming “scientists,” makes it even more suspect to me.
One thing I never quite understand is why those who believe in evolution, or creaation for that matter, are so concerned that do not believe in either. What do they care. I’m not trying to convince anyone else to believe what I believe.
I’m only explaining what I believe and why. Others can take it or leave it.
Science is not a debating society.
Im only explaining what I believe and why.
You didn't say "I believe there are no new species", you said, unequivocally, "there are no new species."
An absolute, such as that, requires proof. And, you gave no 'why', at all.