Showing posts with label fused chromosomes. Show all posts
Showing posts with label fused chromosomes. Show all posts

Friday, August 22, 2008

Eric Hovind's attempt to explain away the fused chromosomes

You all know the argument for evolution from the fused chromosomes, for those who don't; I wrote about it in an earlier post, I'll explain it briefly here for conveniance; apes have 48 chromosomes and humans have 46, and one thing is that if we don't find an explanation for this evolution is in trouble. What would have had to have happened is that two of the chromosomes fused into one large chromosome, and interestingly enough our chromosome number 2 is resembles to ape chromosomes which fused. What a coincidence!

This is a little difficult for creationists to explain away although they have found a way, AiG has written an article in response to the argument by Kenneth Miller. This version of the argument is from a video by Eric Hovind and Jonathan Samson, Samson gives the argument;
So it we strip away the bias and just look at the facts (as everyone should),
the facts are; yes it seems like humans have experienced fusion in the past in
human chromosome number two. But what does that mean? [Hovind cuts in to say
"That's how--there interpreting it--as evidence of evolution"] It means they're
attaching it to their own story.

So essentially he is saying that we are assuming that humans evolved from apes before we look at the evidence and have misinterpreted it as evidence of common descent. Of course is this accurate? Evolution gave a plausible explanation of the missing chromosome and it has turned out to be true. Also since it resembles two ape chromosomes and it predicted by the theory of evolution it doesn't seem too far fetched to say it is evidence of evolution.

This argument is not filled with the usual crass scientific ignorance that usually accompanies Hovind arguments, but it still does not succeed. I think creationists have a point with worldviews affecting how we approach science but they take it to the far flung extant to try to force-fit scientific data into their narrow, flawed interpretation of the bible (which they somewhat arrogantly equate with the biblical position). Christian or non-Christian, one can not accept such an extrapolation.

Monday, April 21, 2008

Answers In Genesis on the fused chromosomes

A little while back I read an AiG article entitled Tail of Two Chromosomes. It was answering Kenneth Miller's argument for human evolution from earlier primates (that the human chromosome number two was the result of the fusing of two chimpanzee chromosomes). It basically said that it is the result of two human chromosomes fusing. The claimed that in other species it is connected to illnesses. And that it does not lead to speciation. After asking Miller himself I realized that the author of the article was missing the point of the article, this is what he said in his reply;


Thanks very much for your note:

[my email to him]
Hi I'm a high school freshman from
Temecula, I have reviewed your analysis of creationism and it seems reasonable.
I have been looking for a response to a creationist response to your fused
chromosome argument found here
http://www.answersingenesis.org/articles/am/v2/n4/tale-of-two-chromosomes,
they appear to do a good job in defending their case against common descent
(which being an evangelical I am rather pleased I'll admit) but I am still
skeptical, since I could not find a good rebuttal to it I have decided to ask
you personally to review it.

[his response]
I read the article, and was
absolutely amazed at how completely its author missed the point. The fact
that one of our chromosomes has a fusion site within it is not what makes us
different from other primates, and it is not what makes us human. Most of
the "rebuttal" is directed against those two points - which I have never
made.
The real issue is simple. Do we or do we
not share common ancestry with the other great apes, all of which have 48
chromosomes. If we do share such ancestry, then evolution makes a
straightforward, testable prediction.... namely, that two primate chromosomes
must have fused together in the line leading to us, and that our genomes should
carry the evidence of that fusion. If we do not find that fusion point,
then evolution in terms of common ancestry for our species would be argued
against.
The fact that the prediction is fulfilled is a powerful
confirmation of the evolutionary ancestry of our species. It does not
answer the question of how our genetic information differs from other primates,
nor was it meant to. It simply is a test of common ancestry, a test that
evolution passes.
Has any creationist ever made such a specific
prediction to put their hypotheses to such a scientific test? I believe
that the answer is no.
Best Wishes,
Ken



Now to explain what this means to those who don't have as much science up their sleeves; as you know we humans have 46 chromosomes, 23 from each parent. Now great apes (chimpanzees, gorrillas etc.) have 48 chromosomes. Now what would have to have happened between them nd us is that two of the chromosomes would have had to fuse together. And sure enough our chromosome number 2 is made of two fused chromosomes. How do we know this? Well on the ends of chromosomes are caps called telomeres (which dammage to them is linked to aging). Well on a fused chromosome there would be two talomeres end to end. And sure enough there are. This is evidence of common descent. This does not show very well on the creationist's part. I hate to be the bad guy to my creationist companions and family, but it appears this is good evidence of common descent. This is of course helped out by ERVs (nasty little buggers that invade our cells and can fuse their RNA into our genome) and the fact that we have found many transitional fossils, one such interesting fossil is tiktaalik, a fish which has the rudiments of legs and a neck. If anybody has n objection to the evidence I have put forth please do, I welcome debate and discussion.