dr Gerdien de Jong
3584 CH Utrecht
||tel + 31 30 253 2246
fax + 31 30 251 3655
Evangelische Omroep /Evangelical Broadcasting
English / Engels
pdf documenting editing in episode 1
pdf documenting editing in episode 2
Nederlands / Dutch
pdf documenteert veranderingen in episode 1
pdf documenteert veranderingen in episode 2
Episode 10 ontbreekt
EO Censuur 2
knippen in episode 1
EO Censuur 3
knippen in episode 2
Englisch / Engels
Mammals creationist version 1
cuts in episode 1
of Mammals creationist version 2
cuts in episode 2
of Mammals creationist version 3
episode 10 missing; BBC
My research interests are a combination of experimental and theoretical work,
on a number of subjects.
- Drosophila research
- Theoretical work
1 Drosophila research
Body size in Drosophila differs between species, between geographical
populations within a species and between different environmental conditions
given the same genotype. A sufficient explanation is lacking in all three cases.
Body size itself might be selected, but an alternative explanation is that the
physiology leading to body size is under selection.
Body size in Drosophila melanogaster differs if larvae are raised
under different temperatures. Body dimensions as wing length and thorax length
have a maximum at an intermediate temperature. My interest is whether larval
temperature conditions differences in physiology that lead to different body
Body size differs between natural populations of Drosophila melanogaster,
larger body size being associated with more temperature latitudes. A preliminary
hypothesis is that at more temperate latitudes, food availability is less
predictable, and starvation resistance under stronger selection. Selection for
starvation resistance would select for high larval food storage and large body
size. Large body size would come about by high larval efficiency in physiology.
My interest is in physiological differences between geographic populations, and
the genetics underlying physiological differences. Part of the question is
whether many physiological traits are correlated with body size, and under the
control of simultaneously regulated genes.
Drosophila species share a very comparable genome, but differ highly in size.
The genomics of (quantitative) differences between species is one of the major
challenges of biological research.
2 Theoretical work
My theoretical interests are in combining ecological and genetic modeling in
order to obtain theories of the influence of ecological processes as density
dependent number regulation on the evolution of phenotypically plastic traits
and life histories. The challenge for the future is to extend the existing
theory, and to use experimental ecology and evolution to test the theoretical
I'm continuing my research on the quantitative genetics of reaction norms.
Density dependent number regulation exerts a large influence on the evolved
optimized reaction norm. As a consequence, discrete regions with food show
different patterns of evolved reaction norms, The reaction norms can differ to
the extend that speciation is indicated.
Life history theory lacks explicit density dependent number regulation. I've
developed a model for ESS clutch size in birds under density dependent number
regulation. The model leads to the lowest possible optimum clutch size at the
lowest maximum fitness that is consistent with population existence, and to the
maximum number of individuals in the population. The model shows that age low
fecundity in log live birds, together with high age of maturity, is not a
consequence of inherent genetic trade-offs but of demographic constraints as
stable population size.
At present(2006), my main teaching is a level-3 course for 2nd year biology
Evolutionary Ecology. The second
teaching commitment is a level-2 course at the start of the second year on
Publications from 1990