X-Message-Number: 17353 Date: Wed, 22 Aug 2001 14:15:40 +0000 From: Kennita Watson <> Subject: Oxygen surfeit? Yvan Bozzonetti wrote: > The question is: what is the optimum O2 level? it must come from an > adaptative process, so I would say it is the atmospheric level in african > pains (the origin domain of man). Now, evolution has a fair amount of > inertia and O2 level has not always been what it is now. At some epoch it > peaked at near 30 per cent... Because actual level is rather low on the > historical scale, I would guess we are adapted to an optimum higher than > the current partial pressure in the atmosphere. This was my basic logic > for testing atmospheric content with more O2. Note that, by that logic, we are also adapted to an optimum life span of 20-30 years. The 02 level is low on the historical scale; life span is high. I won't claim a direct correlation, but it is worth considering. Note also that the evolutionary processes that gave rise to humans had no reason to optimize our oxygen metabolism; it was good enough. As far as that goes, maybe more oxygen _is_ better for reproduction -- running from tigers. toiling in fields, nourishing fetuses, etc. I don't think it follows that it's better for longevity. -- May you live long and prosper, Kennita -- Kennita Watson | Way Cool Internet Radio: http://www.live365.com | http://www.kennita.com | Great Minds Think Alive! -- Lee Corbin Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=17353