e hënë, 9 korrik 2007

The problem of species has profoundly changed since 1859



The problem of species has profoundly changed since 1859. For
Darwin it was perforce a problem of adaptation. For the
investigator of to-day it has become a part of the more
inclusive problem of variation. Along with the logical results
of natural selection he contemplates the biological processes
of organic differentiation. He is no longer satisfied to assume
the existence of those modifications that make selection
possible. In his efforts to control them, the conception of
adaptation as a result has been crowded from the center of his
interest by the conception of adaptation as a process.


birdseed