Is bacterial
resistance to antibiotics an appropriate example of evolutionary change?
[Is bacterial
resistance to antibiotics an appropriate example of evolutionary change? Kevin
Anderson, Ph.D.] "[Summary quoted directly from the actual paper]
"[Summary]...Resistance to antibiotics and other antimicrobials is often claimed to be a
clear demonstration of “evolution in a Petri dish.” However, analysis of the
genetic events causing this resistance reveals that they are not consistent with
the genetic events necessary for evolution (defined as common “descent with
modification”). Rather, resistance resulting from horizontal gene transfer
merely provides a mechanism for transferring pre-existing resistance genes.
Horizontal transfer does not provide a mechanism for the origin of those genes.
Spontaneous mutation does provide a potential genetic mechanism for the origin
of these genes, but such an origin has never been demonstrated. Instead, all
known examples of antibiotic resistance via mutation are inconsistent with the
genetic requirements of evolution. These mutations result in the loss of
pre-existing cellular systems/activities, such as porins and other transport
systems, regulatory systems, enzyme activity, and protein binding. Antibiotic
resistance may also impart some decrease of “relative fitness” (severe in a few
cases), although for many mutants this is compensated by reversion. The real
biological cost, though, is loss of pre-existing systems and activities. Such
losses are never compensated, unless resistance is lost, and cannot validly be
offered as examples of true evolutionary change." Is bacterial resistance to
antibiotics an appropriate example of evolutionary change? Anderson,
Is Bacterial Resistance to Antibiotics an Appropriate Example of Evolutionary
Change?
Is bacterial resistance to antibiotics an appropriate example of evolutionary change?