Is Evolution Reversible? Dr. Jeff Gore, Assistant Professor of Physics, MIT; 2007-10 Fellow (Biophysics) The degree to which evolutionary changes are reversible has long intrigued biologists.  A famous example of reversibility in evolution is the emergence and subsequent loss of legs in the lineage that led to snakes. However, studies of enzymatic evolution suggest that it is possible for evolution to become “stuck,” even if the original form of the enzyme is more fit in the new environment. In this talk, I’ll describe our experiments probing the reversibility of evolution during bacterial adaptation to different antibiotics.