From: ((Steven B. Harris))
Subject: Re: C-14 and aging: but ---> K-40
Date: 30 Jun 1995

In <3sukc4$o91@highway.LeidenUniv.nl> none@nl (Angelo Schouten) writes:

>I think the major exposure to endo-radiation is due to potassium K40. The
>natural abundance exceeds *many* times over your *supposedly* C14 hazard.

Not abundance-- it's radioactivity (function of abundance and halflife).
And yes, many people do not realize that a beta ray from K-40 can bust a
chromosome just as effectively as if a carbon atom that was part of the
DNA backbone decayed.

>Nevertheless there is absolute nothing you can do about that (your
>organism will take of that, it took evolution to do so). I recall some
>comments on K-40 and human evolution. It was suggested that due to
>mutations caused by i.g. K-40, intelligent life came to be what they are
>today.

Hogwash.  Something happened to "chimps" over 10 million years to make
them people, but whatever it was, it sure wasn't K-40.  As you see from
dinosaurs and every other kind of critter, evolution of brains doesn't
just happen by itself, and surely is not guaranteed over time.

My guess is that the "East side story" will prove correct.  The great
rift valley opened by tectonic action, and apes were isolated in the
East onto what rapidly became Savannah.   It was adapt or die, and I'm
sure most died.  We're the descendants of the rest.   They had to loose
their hair to keep from overheating, and also had to stand on their hind
legs like meerkats.  Those that learned to walk and throw, got meat--
increasingly the only source of food.   Now we're down to 2 million
years ago.  Hunting in bands like wolves required communications skills,
and those that could communicate got fed, too.  And, I imagine, got the
females.  I suspect that the human brain is a bit like the peacock's
tail in that regard; the peacock's tail has colors only because peahens
see color.  The human brain started getting larger very fast long after
we could walk well-- in fact I will guess, just about the time that
speech for the first time let the female of the species directly
evaluate one of the more important organs of survival in a hunting
group.  Speach lets you "see" the brain, and sexual selection has to be
important from there.  The human brain is our "peacock's tail":  bigger
than it needs to be from the viewpoint of physics and evolution, and
from those viewpoints, just as silly.



                                            Steve