Campuses:

Mathematical Modeling of Evolutionary Diversification

Monday, September 9, 2013 - 9:15am - 10:30am
Jasmine Foo (University of Minnesota, Twin Cities), Natalia Komarova (University of California, Irvine)
Evolutionary diversification is one of the central concepts in ecology. The mechanisms leading to diversification of species in geographic isolation are well understood. There is however another scenario of diversification (sympatric diversification) whereby speciation occurs without the geographical separation of diverging populations. While it is becoming increasingly apparent that sympatric diversification is an important source of biological diversity, its underlying mechanisms are poorly characterized.

In two recent papers [1,2], experimental results are reported where sympatric diversification was observed in several E. coli bacterial systems. The observed evolutionary dynamics were driven at least in part by a co-­‐evolutionary process, in which mutations causing one type of physiology changed the ecological environment, which in turn allowed the invasion of mutations causing an alternate physiology. The parallel genetic changes underlying similar phenotypes in independently evolved lineages provided the first ever empirical evidence of adaptive diversification as a predictable evolutionary process [1]

In this project, we will work on creating a mathematical model that can describe the observed data. In particular, we will work on an explanation of the observed coexistence of two different types of bacteria in the same spatial location. As a reference point, we will use existing mathematical models of adaptive diversification due to frequency-­‐dependent ecological interactions.

The project will involve the parts: (1) Exploration/model construction, (2) Model validation by comparing with the experimental data in [1,2], (3) Explanation of the observed process of diversification and coexistence. The work will include both analytical and numerical components.

References

[1] Herron, Matthew D., and Michael Doebeli. Parallel evolutionary dynamics of adaptive diversification in Escherichia coli. PLoS biology 11.2 (2013): e1001490.

[2] Burgess, Darren J. Evolution: Experimental evolution probes neighbourly niches. Nature Reviews Genetics (2013).