DIMACS Seminar on Math and CS in Biology
Title:
Sex and the escape from mutational meltdown
Speaker:
- Professor Robert C. Vrijenhoek, Director
- Center for Theoretical and Applied Genetics, Rutgers University
Place:
- The Waksman Institute, Room 1001
- Busch Campus, Rutgers University
Time:
- 3:00 PM
- Monday, March 6, 1995
Abstract:
Sexual reproduction in higher organisms is generally believed to be a
mechanism that produces recombinational variability among an
individual's offspring. This variability increases the scope for
natural selection and adaptation in a spatially heterogeneous and
temporally changing environment. Because asexual organisms lack
recombinational variability, they are thought to be "evolutionary
dead-ends." They may flourish temporarily, but will ultimately
disappear because of evolutionary inflexibility. Studies of related
sexual and asexual lineages of fish in the genus Poeciliopsis have
generally supported this scenario. Evidence from mitochondrial DNA
indicates that asexual lineages are short-lived and recent compared to
sexual lineages. Also, examination of nuclear genes revealed that the
asexual lineages have accumulated numerous potentially deleterious
mutations that eventually will lead to a "mutational meltdown."
We have recently discovered an escape from this asexual doomsday scenario,
in the form a new sexual species that had asexual ancestors. The genealogy
of this new species is traced over what we assume to be at least one
hundred thousand generations with nuclear and mitochondrial genetic
markers.
Upcoming talks
- March 13, Spring break
- March 20, Protein Structure Workshop
- March 27, Dr. Sampath Kannan, U. Penn
- April 3, Dr. Donald Beaver, Penn State Univ.
Document last modified on February 28, 1995