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Author
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Topic: Genetic Mechanisms of Evolution
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Deanne M. Taylor
Member
Member # 274
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posted 17. May 2002 14:09
I'd just like to say that by reading through this board, I've noticed many people citing modern evolutionary theory as holding to the mutate-select-mutate paradigm. However, that simplistic view is over a decade out of date at this time. It went out of date with the first releases of the sequences in the various genome projects.
It would be understandably better if both sides educated themselves on the actual current state of research into the evidence of genetic mechanisms of evolution instead of basing their arguments on an old and more incomplete picture. While nobody is saying we understand the mechanisms for evolution completely, there is nothing in any of the recent evidence for genetic restructuring over time (evolution) that conflicts with Darwinism or natural selection.
Since many genomic studies are done based on mathematics and the same kind of "information theory" and condensed-matter-physics methods that are used to try to disprove Darwinian evolution, it would be interesting to see where the conflicts between the two points of view meet.
I would be interested in what ID proponents have to say about recent evidence of gene innovation (gene creation) in the primate lineage in which some primate-specific genes show strong evidence of positive selection. The data itself, as well as the analytical methods, are up for debate.
To be more clear, here is a summary of discoveries by Evan Eichler and others:
1) Evidence that chromosomes swap whole swaths of material with one another, often duplicating genes. Some of these genes are functional, some are not (they become pseudogenes). We are certain these are duplicated segments because they retain the old fingerprint of the old location even in the new location, as if they were copied, wholesale. The research was restricted to those duplications which held a high degree of similarity (>95% I believe) and these duplications include bits of the old location that have no functional relevance in the new location.
2) The repeated genes within these swapped regions then show evidence of strong positive selection, where the level of mutations in the non-coding part of those genes is lower than the mutations in the coding part of those genes. Therefore these genes were essentially duplicated between chromosomes and allowed to drift mutationally, each time selected for a particular kind of mutation. Eichler finds these evidences in the hominid genomes (old world, new world apes).
3) These postitive selection trends appear most markedly (mathematically) in reproductive genes, xenobiotic-recognition genes/immune system genes, and sexual selective genes.
There are other mechanisms posited besides segmental duplication which have evidence apparent in the genetic code, including polyploidy and LINE/SINE elements.
More information on seg dup can be found in the abstracts on this page:
http://www3.ncbi.nlm.nih.gov/htbin-post/Entrez/query?db=0&form=1&term=Eichler+EE
Thank you.
[ 17 May 2002, 15:04: Message edited by: Moderator ]
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Moderator
Administrator
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posted 17. May 2002 15:14
Dear Deanne,
First off, welcome to Brainstorms!
Second, I changed the title of your post to better reflect the direction I'd like this thread to go.
Third, your post borders on being a "corrective" thread rather than giving us a sense of a new insight or idea that you want us to consider. "Corrective" posts should never start threads but rather be posted within threads that already exist. They should be used for constructive critique. New threads at Brainstorms should always consist of new and positive ideas.
I'm going to give you two days to give this thread direction, to develop your ideas on genetic mechanisms of evolution. After this time, if I do not see progress being made, I will shut it down. If the post deteriorates before hand, I will not hesitate to click "Close Topic" a bit early ![[Wink]](wink.gif)
Thank you.
[ 17 May 2002, 15:15: Message edited by: Moderator ]
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