David MacMillan sent the following e-mail to me and a handful of others. He directed us to this article from the Sacramento Bee, which describes how a biologist, Michel Milinkovitch, discovered a bearded dragon that lacked both scales and beard. He bought the reptile from a breeder and, with his graduate student, Nicolas Di-Po, sequenced its genome and discovered that the same gene codes for scales in reptiles, feathers in birds, and hair in mammals. The only sensible conclusion that may be drawn is that reptiles, birds, and mammals share a common ancestor. Herewith, Mr. MacMillan’s e-mail, reproduced with permission:
A bearded dragon was born without any scales, leading to what may turn out to be one of the most exciting evolutionary discoveries of the decade.
Can’t wait to see how creationists – particularly the ones at Answers in Genesis – try to spin this.
This lizard was found by a biologist in a pet store. Curious, he decided to buy it and have its DNA sequenced. By comparing its DNA to “normal” bearded dragon DNA, they were able to locate the gene that is typically responsible for the formation of scales in reptiles. Big surprise: it’s the exact same gene responsible for the formation of feathers in birds and hair in mammals.
It was already known that the gene for feathers in birds matched the gene for hair in mammals. Because common descent requires that birds and mammals both evolved from reptiles, this commonality represented a major limitation on the origin of scales. If the gene for scales didn’t match, it would seriously challenge a major framework of common descent.
Not only did the discovery allow scientists to verify this prediction, but it also gave them the information they needed to find and observe scale development in reptile embryos. Sure enough, it too matched the time of hair development in mammals and feather development in birds. Well-informed readers will not that this is not embryonic recapitulation; rather, it is a common developmental cycle resulting from common ancestry. This product of evolutionary science enables new understanding of life in the here and now.
How will Answers in Genesis respond? I’m not sure – but I can make some educated guesses.
“This is a clear example that mutations are always harmful.”
“This lizard, rather than progressing upward, has lost information (an example of microevolution) and has not changed ‘kinds’ (as required by macroevolution).”
Of course these miss the point completely; this particular lizard’s mutation merely allowed for another discovery.
“The belief that this gene can be used to trace common origins of reptiles, birds, and mammals is an evolutionary assumption based on the naturalistic presuppositions of secular scientists.”
“Even if it is proven that this same gene does control scales, feathers, and hair, this would be a demonstration of common design within the Biblical worldview.”
These miss the point that this is a necessary prediction of the evolutionary model.
Any other possible answers?