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To: bobbdobbs

Are we evolving into something else was my question. Dna does not evolve does it? It only mutates into a disease? Environmental adaptation was not the question. Real adaptation would be those living in the northern states to start growing coats of fur for the winter months.


99 posted on 03/24/2006 3:16:54 PM PST by John 6.66=Mark of the Beast?
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To: John 6.66=Mark of the Beast?
Dna does not evolve does it? It only mutates into a disease?

I get the impression you don't know a lot about DNA and evolution.

Your DNA is made of non-coding regions interspersed with coding regions, which are the genes. Each gene produces a gene product (ignoring alternative splicing for the moment!), which usually is a protein. Some of these proteins are the proteins we usually think of, like enzymes. However, a great number of them have their role in interacting with the DNA to cause certain genes to either be transcribed to RNA more often or to be transcribed less often.

If you got a group of people and looked at the DNA sequences for one of their genes, you would find that they weren't all alike. Probably a few people would share one sequence, a few would share a different one, and then others would have a third variant. Each variant sequence for the gene is called an allele. Most genes have multiple possible alleles. New alleles arise through mutation of existing ones.

It is also possible to add new genes. There are several mechanisms for doing this. One of the most common is duplication--a region of the DNA is accidentally duplicated, usually leaving a copy of the gene next to the old gene. When this happens there are two copies of the gene, and one of the copies can then mutate freely and in the end produce a product with an entirely different function than the parent gene. We can see this with the HOX genes and hemoglobin family, for example.

In order to produce the protein product, the DNA is first transcribed into RNA. Then the RNA is translated into a protein. Each triplet of bases codes for one amino acid, and there is a lot of redundancy in the code. Because of this a mutation doesn't necessarily change the protein product at all. Many mutations are silent. Others are harmful, and others are beneficial.

So once again, if we don't become extinct we will eventually evolve into something else. However, it's hard to say what that might be without being able to see millions of years into the future.

106 posted on 03/24/2006 3:37:38 PM PST by ahayes
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To: John 6.66=Mark of the Beast?
" Dna does not evolve does it? It only mutates into a disease?"

Into a disease? That's a new one.
122 posted on 03/24/2006 4:25:11 PM PST by CarolinaGuitarman ("There is grandeur in this view of life...")
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To: John 6.66=Mark of the Beast?
Dna does not evolve does it? It only mutates into a disease?

incorrect. most mutations are irrelevant, neither positive nor negative in consequence, indeed imperceptable in the phenotype of the mutant organism.

heritable mutations add up over generations, leading to differentiation inside a population. many of these substantially mutated subgroups are selected against by environmental and other factors, but some are not.

such accumulated mutation through multiple generations sometimes eventually leads to divergent descendant strains - this is called speciation through imperfect replication and (natural) selection, aka "the theory of evolution".

137 posted on 03/24/2006 4:42:50 PM PST by King Prout (many complain I am overly literal. this would not be a problem if so many were not under-precise)
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