Blinn

Vanderzyden, do you understand the physical properties of chromosomes?

Each one consists of a DNA molecule that is tightly bound up with two kinds of proteins, histones and nonhistones. This mass of material is called chromatin. Histones contain large amounts of the amino acids lysine and arginine, which gives them an overall positive charge. DNA contains negatively charged phosphates, so DNA and histones bind tightly to each other. It’s not a problem for broken ends of chromosomes to “stick” together, or fuse. In fact, teleomeres have special properties which render them "non-sticky," and that’s why they’re on the ends of chromosomes – to keep chromosomes from sticking to each other. So are you now going to question the existence of proteins or amino acids? How about the bonding properties of oppositely charged molecules? It’s not dogmatic to expect someone who is reading about chromosome fusion to have a solid understanding of organic chemistry and biochemistry. By doubting a simple phenomenon that’s be recognized for over 60 years, you’re showing us just how little biological knowledge you have.

Oolon Colluphid

There's a surprise .

Vander, get a textbook. Get an education. Get a clue.

Oolon Colluphid

Oh yeah, and back to my first point above:
Tell us why chromosomes cannot fuse.

TTFN, Oolon

S2Focus

You have demonstrated no such thing. Indeed, you have demonstrated nothing more than that you are yet another data point that supports the thesis of <a href="http://www.apa.org/journals/psp/psp7761121.html" target="_blank">this peer-reviewed journal article</a>.

[ August 29, 2002: Message edited by: S2Focus ]</p>

Albion

And once again the goalpost sprouts wings. The use of lab systems to model natural systems is standard throughout science. The researchers are taking advantage of the natural mechanisms and pathways available in the system to do their manipulations, they aren't forcing the lab system to do something it's incapable of doing in nature - what use would that be?

Someone asked on another thread what creationists will say when scientists do manage to synthesise a replicating cell in the lab. I think we've just seen the answer - it doesn't count unless you can do it in the wild. The goalpost moves from "show me that it's possible" to "show me that it happens," even though it might take millions of years to happen or do so under conditions where humans can't get access to. And if it ever IS demonstrated, the goalpost will move again to "show me it happening fifty million years ago."

I hope you're honest enough to never use medicines whose safety and efficacy have been tested in lab experiments that model the natural world but insist on only using remedies that have never seen the inside of a lab. Otherwise your objection is hypocritical.

Bracer

Oh wow. That one's getting bookmarked -- to keep in mind about myself in discussions as much as anything .

Thanks bunches S2F!

davidm

I'm no scientist, but have always accepted the fact of evolution based on general reading and education. The evidence is overwhelmingly persuasive, and the entire model offers such an elegant explanation for what we see around us.

I've learned a lot of details reading through these threads, and I'm sure that is true for a lot of people. So respondents shouldn't think they've wasted their breath. A question: On chromosome fusion, surely there are some other important differences between humans and chimps? Or can we look at a chimp and say, "There but for the grace of a single chromosomal fusion event go I?" If I've missed something please let me know.

To creationists: Why does your belief in God hinge on rejecting evolution? The bible doesn't say anything about gravity, I don't suppose. Should we therefore believe that angels move things up and down and all around until this idea is conclusively refuted (however that may be done)? Can't you see the creation story as an allegory? Why not? (I realize this is off-topic.) thnx.

Valentine Pontifex

And I might actually mention that these examples are not from those evilutionists. The link is to a creationist organization: YECs in fact.

Mageth

Thanks, Lord Valentine, for pointing that out!

It's nice to know that some Creationists actually attempt to understand the science and consider the evidence rather than just denying it exists.

Blinn

Hi David,

The historical event of a fusion is not what accounts for the differences between us and chimps. We could still have 48 chromosomes - the differences are found in about 1 percent of the DNA wound up in those chromosomes. I'll try an analogy - consider chromosomes to be "boxes" where all of our volumes of the "DNA encyclopedia" are stored. Flip through the thousands of pages in the human set and you'll find a paragraphs here and there that are different from the chimp's set of books. These paragraphs account for the differences. At one point in the past humans took two of our boxes of books and consolidated them into a single larger box. It didn't do anything to the pages in the books, just changed how we've got them packed up. Hope that makes sense.

Also, I think this is worth posting again. Look at these populations of pocket mice. They all belong to the same species, but they've had some fissions and fusions going on in their chromosomes. Potentially, fission/fusion could cause some disruption leading to reproductive isolation among these groups, and then they'd start diverging genetically.



[ August 29, 2002: Message edited by: Zetek ]</p>