Creationists frequently claim that new genes (what they call information) can't arise in the genome.
This seems to be based on the "kinds" idea, where the initial creation was perfect and its genome has been devolving ever since "the curse" due to the effects of sin. (Forgive me if these details are not exact.)
For the purpose of this discussion, we can define
genes as "information" in the broad sense. As creationist Carl Wieland notes (in the article cited below):
quote:
[Darwin] did not know, for instance, that what is passed on in reproduction is essentially a whole lot of parcels of information (genes), or coded instructions.
It cannot be stressed enough that what natural selection actually does is get rid of information. It is not capable of creating anything new, by definition.
Science has been finding that the opposite is true. New information (genes) can and do arise in the genome.
This article:
Recipes for life: How genes evolve confirms that new genes do indeed arise, and describes some of the mechanisms of how that occurs.
It is difficult to summarize this article, or to include a small number of paragraphs that encapsulate the findings.
Here are three that begin to describe some of the findings:
quote:
The most obvious way for a new gene to evolve is through the gradual accumulation of small, beneficial mutations. Less obvious is how an existing gene that already does something important can evolve into a different gene. The scope for such a gene to change tack without capsizing the organism that carries it is very limited. However, as biologists realised a century ago, this constraint no longer applies when mutations produce an entire extra copy of a gene. ...
Some theoretical biologists think gene copies can also be preserved by other, more subtle, mechanisms, but the real challenge to the classical model comes from actual studies of new genes in various organisms. Earlier this year, in the most comprehensive study of its kind yet, a team led by Wen Wang of Kunming Institute of Zoology in Yunnan, China, looked at several closely related species of fruit fly. By comparing their genomes, Wang was able to identify new genes that have evolved in the 13 million years or so since these species split from a common ancestor.
One of Wang's surprise discoveries was that around 10 per cent of the new genes had arisen through a process called retroposition. This occurs when messenger RNA copies of genes - the blueprints sent to a cell's protein-making factories (see diagram) - are turned back into DNA that is then inserted somewhere else in the genome. Many viruses and genetic parasites copy themselves through retroposition, and the enzymes they produce sometimes accidentally retropose the RNA of their host cells.
I think that this article is important because it is filling in some of the details by which evolution occurs, and because it contradicts a claim often made by creationists (such as
Carl Wieland) who claims that "Natural selection adds no information [genes], in fact it reduces it" and "Evolution requires a way to add new information [genes]."
Discuss.
Edited by Coyote, : No reason given.
Edited by Coyote, : No reason given.
Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
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