My research area is mathematical population genetics.
Population genetics is concerned with the study of the genetic composition of
populations. This composition may be changed by segregation, selection,
mutation, recombination, mating structure, migration, and other genetic,
ecological, and evolutionary factors. Therefore, in population genetics these
mechanisms and their interactions and evolutionary consequences are investigated.
It provides the basis for understanding the evolutionary processes that have
led to the diversity of life we encounter and admire. Mathematical models have
played a central role in population genetics since its beginning in the early
twentieth century. They are based on Mendel's laws and often seek to predict
the between-generation change in gene frequencies or, more generally, in the
distribution of trait values within a population that is subject to some of the
above mentioned evolutionary forces. Other branches of population genetics are
concerned with inferring the evolutionary processes that shaped contemporary
populations from genetic data extracted from those populations.
Much of my research has been
concerned with the equilibrium and evolutionary properties of the distribution
of quantitative traits under various forms of selection. Such traits are
typically determined by many gene loci, therefore multilocus models have to be
investigated to explore such problems. Among others, I studied models of
mutation, stabilizing selection, and random genetic drift, and derived
approximations for the equilibrium distribution of a quantitative trait subject
to these forces. I analyzed the response of equilibrium populations to various
forms of directional and fluctuating selection, and investigated the role of
recombination and sexual reproduction for the magnitude of the selection
response. Moreover, I applied such models to problems of conservation genetics,
for instance, to determine the extinction risk of a population that is
experiencing a long-term environmental change, such as global warming.
More recently, I have been
working on multilocus models of frequency-dependent selection on a quantitative
trait, as it occurs if individuals of similar phenotype compete for resources
from a continuous spectrum. In combination with assortative mating, such models
are important to understand the conditions that may lead to sympatric
speciation. Currently, most of my research focuses on the evolution in subdivided
populations, in particular, on the role of migration in maintaining
polymorphism and genetic diversity at multiple loci.
I have also (co-)authored a
number of papers on the evolution of multivariate quantitative traits and the
G-matrix, on the evolutionary consequences of deleterious mutations, on the
fixation probability of alleles in a finite population, on the evolution of
dominance, on game theory, on the origin of life, on evolutionary explanations
for the high phenotypic (i.e., those during transmission and transcription)
mutation rates, on the extinction risk of small populations from genetic,
demographic, and other causes, and on the role of genetic variation in
community ecology.
My book The
Mathematical Theory of Selection, Recombination, and Mutation (published
in 2000 by John
Wiley& Sons,
During the last ten years, my research has been supported by grants from
FWF, WWTF, and NSF.