Evolving radiation resistance

["A Karam" <paksbi@rit.edu>]

One thing to remember about evolution is that it only works if organisms

die before they can reproduce.  Natural background radiation levels,

even in Kerala or Ramsar, are not likely to cause death from cancer when

a person is in their teens or 20s.



We should also remember that natural background radiation is responsible

for only a few percent of spontaneous DNA damage.  This means, again,

that even a dramatic increase in background radiation levels will not

contribute markedly to additional DNA damage and is therefore unlikely

to cause a marked increase in carcinogenesis.



Accordingly, it seems unlikely that living in these areas would

contribute any selection pressure towards developing a resistance to

radiation at these levels.



Sorry....



Andy



P. Andrew Karam, Ph.D., CHP

Research Assistant Professor

Rochester Institute of Technology

Department of Biological Sciences

85 Lomb Memorial Drive

Rochester, NY  14623

+1 585-475-6432

karam@mail.rit.edu



"If A is success in life, then A equals X plus Y plus Z. Work is X; Y is

play; and Z is keeping your mouth shut." - Albert Einstein





-----Original Message-----



One factor that I have not seen discussed in the hormesis debate is

natural 

selection. Since man has for ever been exposed to natural radiation, is

it 

not reasonable to assume that natural selection has reinforced our 

resistance to any deleterious effects? Is it possible that the native 

population of Kerala, for instance, has a greater resistance to

radiation 

than areas with low natural radiation?



My personal (uneducated!) feeling is that reasonable levels of natural 

radiation (and occupational exposures to similar types and energies of 

radiation) is something the human organism (and all other terrestrial 

organisms) has adapted to. And that, as Dale states, the confounding 

factors are so numerous (and over-riding) that confirmation, or

otherwise, 

is extremely difficult.

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