Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Politics : Evolution -- Ignore unavailable to you. Want to Upgrade?

To: Brumar89 who wrote (1410)	6/7/2006 10:35:00 AM
From: TigerPaw	Read Replies (1) \| Respond to of 69300

Sexual recombination" - isn't this just a way of saying reproduction? In what way does reproduction or "sexual recombination" produce variation? There are organisms, mostly single cell but including a lizard, which reproduce without sex. The 'children' are all clone copies of the mother except for mutations. When the reproduction is combined with sexual recombination then a great deal of new variation is introduced. I'll use a simple analogy that is not too far off from the way sex causes combinations. The mother and father gene-DNA strands are in chromosomes (linked lists). The DNA sequences on both sets from mother and father are nearly identical, and so they line up like a zipper closing. The sets aren't absolutely identical (not even including the sex) and so there are traits for eye-color, isulin use, etc. which may be different. In these cases, when the 'zipper closes' it must copy from either mother or father but not both at the same time. Then there might be another sequence that is identical (most genes from the same species are identical) followed by another difference and this time the gene that is included may be from the other parent. The net result is a shuffling of genes, some from the mother some from the father. The process could have errors, either a gene dropped or included twice. Most sex is a very complicated process before it results in a pregnancy. The complexity acts as an error correction mechanism. Most times if the zipping process gets messed up the new cell will not be able to finish the rest of the steps of pregnancy and generally the organism will either not become pregnant or not carry to term. This way the parents don't spend too much resources on offspring that are unlikely to get through later selections. TP