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Liz & Whale

• Behavioral Ecology &
Cultural Evolution

Conservation Biology

Ecosystem & Global Ecology

Evolutionary Biology, Molecular Evolution, & Population Genetics

Physiological & Functional Ecology

Population Biology & Demography

Species Interactions & Community Ecology

Research Opportunities for Undergraduates

Evolutionary Biology, Molecular Evolution, and Population Genetics

interspecific mating
Much of our work has an evolutionary component, including examination of the long-term population genetics of an isolated population of butterflies in Colorado; of genetic changes in native species in the face of pressure from non-native species; of the genetic structure of extinct and extant metapopulation networks of a federally listed butterfly; of the relative roles of sexual and natural selection on wing color signals used in courtship in butterflies.
Research in this area examines how herbivores operate as selective forces on plants, and the evolution of anti-herbivore adaptive responses. Work includes analyses of chemical and biotic defenses via mutualistic interactions of plants with defending ants and wasps.
Current research in the Ehrlich lab is concentrated on a global evaluation of the population-environment-resource situation, with special focus on conservation biology and cultural evolution.
Human genomic variation and its interpretation.  Models for the evolution of genetic interactions.  The evolution of sex and recombination.
pop structure
One of our research foci is the combined effect of ecological and evolutionary dynamics on community assembly. For example, we use experimental populations of the baterium Pseudomonas fluorescens to study the interactive effect of ecological immigration and evolutionary diversification on community development.
Evolution of foraging behavior and colony organization in harvester ants; coevolution of ant-plant-scale mutualisms in tropical forests.
Gordon ants
India Excavation
Phylochronology of small vertebrates of western North America; biogeographic history of mammals from peninsular India
We are using high density oligonucleotide arrays to study speciation and correlate adaptive changes with environmental factors.  We are also applying array technology to gamete recognition and sperm morphology.
S purpuratus
The Petrov group is interested in a wide range of questions in molecular evolution and molecular population genetics.
One key line of research is focused on understanding molecular adaptation. How frequent is adaptation? Does it generally involve mutations of small or large phenotypic effect? Does it tend to involve new mutations or use the standing variation? Are adaptive mutations typically coding or regulatory? How frequent is population-specific versus whole-species adaptations? What effect does recurrent adaptation has on patterns of neutral variation? We carry out whole genome analyses using newly developed methodology to generate putative general answers to these questions and also attempt to verify these putative answers with studies of individual test cases. As part of this research program we are investigating patterns of current adaptation that many organisms are undergoing in response to anthropogenic changes in the environment.
The second major focus is on the evolution of genomes. Why are some genomes small and others large in the sheer amount of DNA? What determined the numbers and kinds of genes found in different genomes? Chromosomal numbers? How do multigene families come to be and maintain their sizes? What role does horizontal gene transfer have on genome evolution? Mutational biases? Natural selection?
We presently study the evolution of social behavior and mutualism, emphasizing the role of cooperation, and using cooperative game theory. We are working on the ``social selection project'' to develop alternatives to sexual selection theory and its corollaries. Previous work in the lab has also investigated the evolutionary community ecology of Caribbean Anolis lizards, the role of coupled oceanic and benthic processes in the population dynamics of intertidal invertebrates, and the theory of ecological economics.
US pop pyramid
Dynamics of phenotypic means and variances. Gene-environment models, evolution of plasticity. Maintenance of variation in nature. Two-sex models of life history evolution.
Stanford Seal Stanford Department of Biology