Re: The role of radioactivity in evolution



Tim Tyler seemysig@xxxxxxxxxxxxxx wrote:-

Albinos get skin cancer because of mutations caused by radiation.

http://www.plasticsurgery-africa.org/albinos.htm

JE:-
The above provides evidence for the evolution of a skin pigment which can
harmlessly absorb UV radiation providing critical skin protection,
especially in the tropics.


According to: http://calorierestriction.org/pmid/?n=2766562

JE:-
Interestingly, no melanomas were detected.


....23.4% of albinos in Johannesburg have skin cancer.

Somatic cell mutations are the cause - but cancer can still
affect the course of evolution via selection.

JE:-
It is more correct to say that random mutation limits skin cancer
development and "the course of evolution via selection". IOW random mutation
cannot control either.

I don't know how radiation-induced mutations compare with
mutations induced by cellular ROS and other garbage - but
my guess would be that - in the absence of radiation defenses -
they could well be fairly significant.

JE:-
Mutation can be repaired.

http://www-personal.k-state.edu/~bethmont/mutdes.html


Cancers can be removed by the immune system.

http://www.niaid.nih.gov/Publications/immune/the_immune_system.pdf.


However, it seems that some tumors are not recognized.

http://www.research.uky.edu/odyssey/fall99/cancerkllers.html

The immune system is under the control of distress/eustress stress levels.

http://library.thinkquest.org/C0123421/what_is_stress.htm

Distress and Eustress are critical density dependent mechanisms.

http://www.lifesci.ucsb.edu/~steele/forrester%20&%20steele%202000%20eco.pdf.


I argue that eustress and distress are required to fitness mutualize
interdependent fertile organism relationships, e.g. predator and prey (no
group selection or organism fitness altruism being required) stopping most
predators from overeating their prey. This complex adaptation is entirely
fertile organism centric and not at all gene centric.

Regards,

John Edser
Independent Researcher

edser@xxxxxxxxxxxxxx




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