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 Main
research projects and goals: Evolutionary Genetics (RG 2)
I. Genes, health & sex: importance of immune
gene variability (MHC, major histocompatibility
complex) in evolutionary biology, behavioural ecology
and conservation (Supervisor Prof. Dr. S. Sommer)
Current discussions in evolutionary ecology and conservation
genetics focus on the relative importance of using selective
neutral markers or markers of coding genes to identify adaptive
and evolutionary relevant processes. Adaptive variation is of
interest because it both reflects historical evolution and determines
the population future phenotypic response to evolutionary processes
conferring the basis for adaptation to environmental changes.
In vertebrates, growing evidence suggests that genetic diversity
is particularly important at the level of the major histocompatibility
complex (MHC) because its gene products play an important role
in immune functions. The central role of the major histocompatibility
complex in terms of parasite and pathogen defense is undoubted.
Moreover, MHC genes also provide direct olfactory cues and are
considered as one of the best candidates for the genetic basis
of mate choice in vertebrates. The remarkable MHC diversity
found in most vertebrate studies to date refers to diversifying
selection acting on this gene complex. We investigate the importance
of overall genetic variability and adaptive MHC-diversity in
gastrointestinal parasite resistance and mate choice as well
as the genetic and fitness consequences of fragmentation and
degradation processes in numerous free-ranging mammal populations
with different levels of genetic diversity and life-history
traits.
- Protection of biodiversity in fragmented landscapes of the
Atlantic plateau of Sao Paulo - Consequences of habitat fragmentation
on the population structure, genetic diversity and parasite
resistance of small mammals of the Brazilian coastal rain forest
(Mata Atlântica) (BMBF, BIOCAPSP).
- Infectious diseases – selection and host-parasite coevolution
- Effects of land use and climatic conditions on gastrointestinal
parasite burden and immune gene variability (MHC) - test of
pathogen-driven selection along a climate gradient in Southern
Africa.
- Genetic variability and immune status of African carnivores.
- MHC diversity of neotropic bats.
- Genes, Sex & Health: MHC, parasites and mate choice
in primates: the role different life history strategies.
II. Adaptational driven population differentiation/speciation
and nature conservation (Supervisor: Dr. J. Fickel)
Many species exist in spatially separated populations. The
restricted gene flow among these populations together with the
array of differing environmental conditions accumulates genetic
differences among the populations over time. Phylogeography
studies the processes controlling the geographic distributions
of lineages by reconstructing the genealogical histories of
genes and populations by explicitly focussing on a species'
biogeographical present and past via integration of genealogical
and distributional information. Events that can be inferred
include population expansion, population bottlenecks, vicariance,
migration, also leading to differing pathogen exposition as
well as to locale environmental and nutritional adaptations.
This is done to evaluate the relative role of historical forces
in shaping the current genetic structure of populations relative
to important ongoing processes.
2. Evolution of adaptive traits in herbivores
- Adaptation to plant anti-nutritive components (Tannins
and proline-rich protins).
- Saisonality and regulation of spermatogenesis (regulation
of growth factor gene expression in Roe deer Capreolus capreolus).
3. Evolution of host-pathogene interactions
- Molecular biology and epidemiology of wildlife relevant
pathogens (e.g. elephant endothelioptropic herpes viruses
EEHV, European brown hare syndrom virus EBHSV).
- Transmission of wildlife relevant pathogens from domestic
animals (e.g. canine distemper, streptococcus sp.).
III. Selection and Adaptation
(Supervisor PD Dr. A. Ludwig)
I am interested on a broad range of scientific topics. Species
and methods are less important than the scientific questions addressed.
Nevertheless, nearly all of my research is linked to evolutionary
biology and conservation using genetics as bridge between them.
In last year’s, ancient DNA analysis came more and more into the
focus of my research, because fossil and archived samples open a
window into the past which could shed light on what we have today.
Natural selection for thermal adaptation on a colder climate was
the major advantage of American Atlantic sturgeon in Europe about
1,200 years ago. Only a very few specimens used this selective advantage
to found a population in Baltic waters. Within a short time frame,
they pushed out their European counterpart from the Baltic. Today,
the Society to Save the Sturgeon with help from our partner Institute
of Freshwater Ecology and Inland Fisheries is dealing with their
restoration. Other brilliant models of powerful selection are domestic
animals. Domestication transformed genotypes and phenotypes in a
very speedy mode. Within a very few generations of selective breeding
domestic’s were far away from their natural counterparts. Addressing
selective traits we try to recognize the starting edge of horse
domestication. Not only had the increase of color variants
also had the existence of colorations which are negatively selected
for in a natural environment mark the isolation between domestic’s
and wild populations. Detailed knowledge about the mode and speed
of these transformations advanced our understanding of evolution
and conservation biology.
- The sturgeon project
- The horse project
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