> Since humans have the capacity to manipulate their environment, they can
> also avert some selective pressures of that environment that jeopardize
> their chances of survival. In other words, while human can do little to
> affect the supply process i.e. make a certain genetic mutation available (at
> least until recently), they can do quite a bit in preventing some of those
> genetic mutations becoming extinct by shielding them form adverse
> environmental pressures.
That is true of many species. They manipulate their environment, and
that manipulation "averts some of the selective pressures of that
environment". Examples: beaver's dams, eagles' nests, primates' tool
use. When any of these species shape their environments and then the
environment "selects" for certain genetic mutations consistent with
those species-made environments, that's natural selection. In fact, you
could say that the history of evolution on this planet consists of plant
and animal species altering their environments to shield themselves from
"adverse environmental pressures"! There's nothing exceptional about
humans in this respect.
> Since human capacity to affect the environment is
> greater than that of other species, it thus follows that humans have a
> greater capacity to control the natural selection process - or at least its
> elimination of the 'life unfit for life' aspect. However, with the progress
> of genetic science, humans are also gaining the capacity to engineer genetic
> mutations and thus selectively affect the supply process of genetic
> variation, which gives them even a greater level of control of the natural
> selection process.
>
> Wojtek
>
Humans cannot "control" the natural selection process. You're
mistakenly assuming there is some inalterable definition of "life fit
for life" that humans can subvert with technological interventions.
Evolution doesn't identify essential types of "life fit for life".
Whatever traits lead to increased survival and reproduction in a given
environment will tend to proliferate in a species; it doesn't matter
what we think is more "suitable" or "advanced". --E.g., lobsters in
dark, deep water evolving to lose their eye stalks is not "de-evolution"
or a subversion of the evolutionary process; it is evolution. Thus if
there is some genetic variant X that once led to lower rates of
reproductive success and is "saved" by technological innovations so that
people with X have higher rates of reproductive success now, that's not
subverting the evolutionary process; it just means that genetic variant
X will be selected for in that specific technological environment, just
like any other trait that leads to high rates of reproductive success in
that environment.
This thread is very strange to me. Everything I've said in this thread is basic stuff covered in an introductory biology class. Why is it so hard for some to comprehend that humans, like all plant and animal species on this planet, are imbricated in the ongoing process of evolution?
Miles