Thursday, July 28, 2005

Wells and Cancer: More Evidence He's Wrong

I have written several posts on this before. They can be found here and here.
From Well's paper on TOPS:

TOPS then explicitly rejects several implications of Darwinian evolution.
These include: (1a) The implication that living things are best understood from
the bottom up, in terms of their molecular constituents. (1b) The implications
that DNA mutations are the raw materials of macroevolution, that embryo
development is controlled by a genetic program, that cancer is a genetic disease,
etc. (1c) The implication that many features of living things are useless vestiges
of random processes, so it is a waste of time to inquire into their functions.


On Science Daily I stumbled across this paper on Multi-Species Genome Comparison Sheds New Light On Evolutionary Processes, Cancer Mutations

A team of researchers from the United States, France and Singapore studied the chromosomes of eight mammals. The mammals are humans, mice, rats, cows, pigs, dogs, cats and horses. Some interesting results emerged:

Using sophisticated computer software to align and compare the mammals' genetic material, or genomes, the team determined that chromosomes tend to break in the same places as species evolve, resulting in rearrangements of their DNA. Prior to the discovery of these breakage hotspots, the prevailing view among scientists was that such rearrangements occurred at random locations.


and:

In their paper, researchers report that the chromosomal abnormalities most frequently associated with human cancer are far more likely to occur in or near the evolutionary breakage hotspots than were less common types of cancer-associated abnormalities. Researchers theorize that the rearrangements seen near breakage hotspots may activate genes that trigger cancer and/or inactivate genes that normally suppress cancer. However, they emphasize that far more work remains to be done to clarify the relationship between cancer and the breakage hotspots. One thing researchers have determined is that the regions immediately flanking the breakage hotspots contain more genes, on average, than the rest of the genome.


Note the cause of chromosome instability has nothing to do with:

Centrosomes that are too numerous or too large would produce too strong a polar ejection force, damaging chromosomes and leading to chromosomal instability.

As Wells tried to argue.

It is interesting to note that the cancer aspects of this research was done within an evolutionary paradigm:

"Science tells us that the most effective tool we currently have to understand our own genome is to compare it with the genomes of other organisms. With each new genome that we sequence, we move closer to filling the gaps in our knowledge," said Dr. Ostrander, who is chief of the Cancer Genetics Branch in NHGRI's Division of Intramural Research.

The multi-species comparison published in Science also yielded surprising results about the rate at which chromosomal evolution occurs. Based on an analysis that included a computer-generated reconstruction of the genomes of long-extinct mammals, researchers found the rate of chromosomal evolution among mammals dramatically accelerated following the extinction of the dinosaurs about 65 million years ago.

Before the sudden demise of dinosaurs and many other types of animals, which is thought to have resulted from a massive comet or asteroid striking Earth, mammals shared fairly similar body plans and also fairly similar genomes. Researchers speculate that the mass extinction opened new ecological niches for mammals, spurring their diversification and the emergence of new mammalian orders. This situation would have facilitated opportunities for the isolation of mammals into more distinct breeding groups, speeding the development of species-specific chromosomes.

"This study has revealed many hidden secrets on the nature and timing of genome evolution in mammals, and it demonstrates how the study of basic evolutionary processes can lead to new insights into the origin of human diseases," said Dr. Lewin, who is director of the Institute of Genomic Biology at the University of Illinois.

Once again proving that nothing in biology makes sense without evolution and incidentally proving wrong, yet agian, those who say evolution has nothing to offer the field of medicine.

To learn more you can go to:

National Human Genome Research Institute