Molecular fossils in DNA

[David Blacklock]

Tracking fossil evidence in DNA means following the histories of mutations in non-coding DNA segments. There are several different kinds of mutations - some of them more unique than a birthmark. When mutations occur in active coding genes (>2% of the genome), an impaired embryo usually results and neither the new life-form nor the new mutation survives. The mutations that occur in most non-coding segments of DNA have no effect on the embryo, so the life-form is normal, and any mutations accumulate harmlessly in that life-form and its descendants. The earlier on the "tree of life" the mutation occurs, the more species will carry it. Our DNA is full of these gene-prints left by our ancestors.

Here's the simple version of how it works: Orangutans, gorillas, chimps, and humans all had a common ancestor. Then orangutans forked off, leaving gorillas, chimps and humans. Then gorillas forked off, leaving chimps and humans. If a mutation is not in gorillas, chimps, or humans but is in orangutans; you know the mutation happened after orangutans forked off from the common ancestor to all four. If a given mutation is in gorillas but not in the chimps, you can expect it won't be in humans, either.

With a boost from the human genome project, hundreds of species' genomes have been published in the last few years. Studying DNA sequences in species thought to be closely related shows exactly when one species branched off in relation to the other. Since you can use this method for all living things, including living species that haven't changed in 400 million years, molecular biologists are having a field day. A few species have been relocated but by and large, the tree of life painstakingly put together from fossil and geological evidence by paleontologists has been confirmed.

If you just want one good example of how to use DNA "fossil" evidence, consider how the 24 chromosomes of the chimp became 23 chromosomes in the human. Briefly, chimp chromosome two and three fused and the very specific chromosomal and molecular details as to what happened are available. Importantly, data like that is only the tip of the iceberg. I've been expecting a book about this subject to come out and it did this spring: "Relics of Eden," by Fairbanks.

DB

[Gman]

David,

It appears you left this part out....

With such incontrovertible documentation throughout the tree of life as recorded in DNA, I have to ask myself how any reasonable person who honestly studies this subject could doubt evolution.

Source: http://www.amazon.com/review/R5HRASYNCV3JV

Well, for the record I guess you could consider me as one of your doubters. Because if God didn't have a hand in it, I doubt if it would have ever happened....

[zoegirl]

David,

It appears you left this part out....

With such incontrovertible documentation throughout the tree of life as recorded in DNA, I have to ask myself how any reasonable person who honestly studies this subject could doubt evolution.

Source: http://www.amazon.com/review/R5HRASYNCV3JV

Well, for the record I guess you could consider me as one of your doubters. Because if God didn't have a hand in it, I doubt if it would have ever happened....

[David Blacklock]

Maybe He greased the wheels all the way. Maybe one of those mutations was the creation of a soul.

DB

[Gman]

Maybe He greased the wheels all the way. Maybe one of those mutations was the creation of a soul.

DB

Well at least you didn't say he used miracle whip.

[David Blacklock]

>>Well at least you didn't say he used miracle whip<<

LOL - good one Gman, but wasn't miracle whip on one of those "bad lists" in Deuteronomy?

[Gman]

>>Well at least you didn't say he used miracle whip<<

LOL - good one Gman, but wasn't miracle whip on one of those "bad lists" in Deuteronomy?

Naw, I think that was cool whip... One of those "whips" anyways.

[David Blacklock]

Now I remember - It was the Senate Majority Whip

DB

[zoegirl]

[David Blacklock]

One type of mutation is called a duplication pseudogene — duplication because certain gene segments are susceptible to being copied, and pseudogene because the copy is non-functional. The original functional gene in question is nicknamed GBA. The human genome has one functional GBA gene and a pseudogene copy nearby. The copy fails to function because a segment of 55 base pairs is missing. In 2005, scientist at the U. of Victoria (Canada) found that chimps and gorillas have the same duplication pseudogene in the same position and with the same 55 base-pair deletions as in humans. Orangutans have the same 2 copies of the GBA gene in the same locations, but both copies of the gene function — the 55 base pairs are there. Squirrel monkeys, by contrast, have only a single copy of the GBA gene. The 55 base pair deletion in the GBA pseudogene is as especially telling mutation because it is very unlikely that it would ever originate more than once.

Most likely, the lineage leading to monkeys diverged from the one leading to humans and the great apes when only one copy of the GBA gene existed. The gene became duplicated in the common ancestor of humans and great apes. Later, one of the copies suffered a 55 base pair deletion in the lineage leading to humans, chimps, and gorillas after it had diverged from the lineage leading to orangutans.

- Mostly verbatim from pages 54 and 55 in “Relics of Eden.”

DB

[David Blacklock]

Either humans share a common ancestry with all living things, or the Creator went to a great deal of trouble to make it look that way, right down to the tiniest details of our DNA. If evolution did not happen, then the Creator certainly has a healthy sense of humor.

For example: Chimp chromosomes differ from humans by 10 major rearrangements — 1 fusion and nine inversions — easily shown down to the molecule. Although chimp and human DNA is said to be 98-99% the same, we should expect to see marked differences in the gene sequences that control brain development. Scientists at U of Cal, Santa Cruz thus searched the genomes of the two, searching for areas of high mutation activity. They found 202 of them, most of them in the regulatory sequences adjacent to the genes. One of the more impressive differences was in gene HAR1F which makes an RNA that is turned on during gestational weeks 7-19, a crucial period for brain development. Of 118 base pairs in that gene, 18 of them differ from chimps, a difference of over 15% compared to the previously mentioned genome-wide difference of only 1-2%. Among the other great apes, none of them have the 18 differences — only humans.

Did natural selection favor those 18 mutations. There are ways to decide whether or not that is likely and the results are being investigated now.

DB

[Canuckster1127]

Either humans share a common ancestry with all living things, or the Creator went to a great deal of trouble to make it look that way, right down to the tiniest details of our DNA. If evolution did not happen, then the Creator certainly has a healthy sense of humor.

For example: Chimp chromosomes differ from humans by 10 major rearrangements — 1 fusion and nine inversions — easily shown down to the molecule. Although chimp and human DNA is said to be 98-99% the same, we should expect to see marked differences in the gene sequences that control brain development. Scientists at U of Cal, Santa Cruz thus searched the genomes of the two, searching for areas of high mutation activity. They found 202 of them, most of them in the regulatory sequences adjacent to the genes. One of the more impressive differences was in gene HAR1F which makes an RNA that is turned on during gestational weeks 7-19, a crucial period for brain development. Of 118 base pairs in that gene, 18 of them differ from chimps, a difference of over 15% compared to the previously mentioned genome-wide difference of only 1-2%. Among the other great apes, none of them have the 18 differences — only humans.

Did natural selection favor those 18 mutations. There are ways to decide whether or not that is likely and the results are being investigated now.

DB

Is it any less plausible that a common creator would account for the similarities?

[David Blacklock]

Hi Bart,

Thanx for responding. Is it plausible? It's completely plausible! The point is that the cumulative nature of the evolutionary changes are recorded in such detail in the DNA, the overall mechanisms He used are rendered transparent.

DB

[Gman]

The point is that the cumulative nature of the evolutionary changes are recorded in such detail in the DNA, the overall mechanisms He used are rendered transparent.

So transparent that they are humorous?

[Jorge]

hmm what about endogenous retroviruses?

http://vwxynot.blogspot.com/2007/06/end ... dence.html
http://godbegone.blogspot.com/2007/10/h ... prove.html