Claim CB932:
Evolution is supposed to advance species, but some modern species, such as
many parasites and species living in caves, appear to be degenerate forms
of other species.
Response:
- Evolution adapts species to their environment. Sometimes that means
becoming more complex, but not always. If losing a feature allows a
species to survive better, the species likely will gradually lose the
feature. Losing a feature is advantageous, for example, if the feature
is energetically costly to grow and maintain (which is almost always
the case) and if it serves no other function (which often happens when
a population moves to a new environment, such as a cave).
created 2003-7-22
