John W. Cox Professor
Talk Title: "Life Has Evolved to Evolve"
Concomitant with the evolution of biological diversity
must have been the evolution of mechanisms that facilitate evolution,
due to the essentially infinite complexity of protein sequence space.
We describe how evolvability can be an object of Darwinian selection,
emphasizing the collective nature of the process. We discuss
computer simulations of protein evolution that quantify this theory.
These simulations demonstrate that rapid or dramatic environmental change
leads to selection for greater evolvability. The selective pressure for
large scale genetic moves, such as DNA exchange, becomes increasingly
strong as the environmental conditions become more uncertain. These
results demonstrate that evolvability is a selectable trait and allow
for the explanation of a large body of experimental results.
Many observations within evolutionary biology, heretofore considered
evolutionary happenstance or accidents, are explained by selection for
evolvability. As specific examaples, we discuss evolution within the
immune system and evolution of drug resistant microrganisims.
Michael W. Deem works in the area of evolution and immunology.
Tools from statistical physics are brought to bear on
problems involving randomness, diversity, and correlations.
Specific current research interests include the immune
response to variable or multi-strain viruses and vaccines,
overcoming immunodominance in therapeutic cancer vaccines,
and understanding how evolution searches the effectively
infinite space of possible DNA and protein sequences.