Why a person doesn't evolve in one lifetime
The body's complicated cell-making process may help to avoid cancer.
It's not easy making a human. Getting from a fertilized egg to a full-grown adult involves a near-miracle of orchestration, with replicating cells acquiring specialized functions in just the right places at the right times. So you'd think that, having done the job once, our bodies would replace cells when required by the simplest means possible.
Comments
Thus it appears that skin cancer might orignate if the stem cells mutate upon exposure to UV rather than TACs.
One of questions that I might ask. Why did the immune system evolve in first place. Making a system for fighting unknown invaders seems unlikely, as evolutionarily we do not know the invaders. I feel the system developed to keep the "normal self" intact and remove "not-normal self" from the system. All the effector responses agaist the pathogens are incidentory.
Thus if the system has to cope up with more "not normal self' to eradicate, the affinity mantuarions etc in the immune system would lead to more chances of tumors.
Posted by: Milind Gore | September 25, 2007 12:39 PM
From "Life, Tomorrow's Comprehension", at
http://blog.360.yahoo.com/blog-P81pQcU1dLBbHgtjQjxG_Q--?cq=1
Chapter II
Natural Selection Is A Two Level Interdependent Affair
1) Evolution ensues from genome/genes modifications ("mutations"), inherently ever more of them as new functional options arise for the organism.
2) Modifications of genome's functional capabilities can be explained by the second-stratum organism's culture-life-experience feedbacks to its genome, its prime/base organism. The route-modification selection of a replicating gene, when it is at its alternative-splicing-steps junctions, is biased by the feedback gained by the genome, the parent organism, from the culture-life-experience of its progeny big organism. THIS IS HOW EVOLUTION COMES ABOUT.
3) The challenge now is to figure out the detailed seperate steps involved in introducing and impressing the big organism's experiences (culture) feedbacks on its founding parents' genome's genes, followed by the detailed seperate steps involved in biasing-directing the genes to prefer-select the biased-favored splicing.
4) I find it astonishing that only very few persons, non-professional as well as professional biologists-evolutionists, have the clear conception that selection for survival occurs on two interdependent levels - (a) during the life of the second-stratum progeny organism in its environment, and (b) during the life of its genome, which is also an organism. Most, if not all, persons think - incorrectly - that evolution is about randomly occurring genes-genome modifications ("mutations") followed with selection by survival of the progeny organism in its environment. Whereas actually evolution is the interdependent , interactive and interenhencing selection at both the two above levels.
end chapter II
Posted by: Dov Henis | September 26, 2007 11:49 AM