On Sep 7, 2009, at 10:49 AM, S. Artesian wrote: > > And the contradiction is crucial, because the hypothesis of >> constancy for the rate of change in mitochondrial DNA depends on the >> assumption of constancy in the environmental conditions determining >> that rate of change... > > Just one point, mutations in mitochondrial DNA are not the product of > changes in the environment. These mutations are not "adaptations," > they are > not "selected." [Most mutations have nothing to do with the > environment]. > In mitochondrial DNA the mutations are random errors in internal > replication, which since there is no exchange of genetic material > through > sexual reproduction, form a "pristine" -- as they cannot be selected > for-- > "clock" for determining the times of the deviation from, and the > origin of, > the "template" mitochondrial DNA. > Mutations in mitochondrial DNA, like all other physical phenomena, are *caused*. Random they may be with respect to the life-history of the individual organisms in which they occur, but the frequency with which they occur in a population is determined by causal factors in the environment. If that frequency, that rate of change, is constant then the relevant environmental causality must also be constant. And that assumption, in the present state of scientific and historical knowledge, is quite unsupportable.
Shane Mage > This cosmos did none of gods or men make, but it > always was and is and shall be: an everlasting fire, > kindling in measures and going out in measures." > > Herakleitos of Ephesos ________________________________________________ YOU MUST clip all extraneous text when replying to a message. Send list submissions to: Marxism@lists.econ.utah.edu Set your options at: http://lists.econ.utah.edu/mailman/options/marxism/archive%40mail-archive.com
