A quantitative test of population genetics using spatiogenetic patterns in bacterial colonies

Area of Science:

• Evolutionary Biology
• Population Genetics
• Microbial Ecology

Background:

• Population genetics theory is central to evolutionary analyses.
• Empirical testing is difficult due to complex spatial-evolutionary relationships.
• Quantitative validation of spatial population genetics models is lacking.

Purpose of the Study:

• To quantitatively test and validate spatial models of population genetics.
• To demonstrate the predictive power of these models in a simplified biological system.
• To explore the interplay between space, dispersal, and evolution in bacterial populations.

Main Methods:

• Combined analytical approaches, on- and off-lattice simulations.
• Conducted experiments using Escherichia coli and Pseudomonas aeruginosa colony biofilms.
• Utilized genetic diversity at the colony periphery to parameterize models.

Main Results:

• Spatiogenetic patterns in bacterial colony biofilms were accurately described by an extended one-dimensional stepping-stone model.
• Model parameterization using peripheral genetic diversity allowed accurate prediction of cell migration.
• The models successfully estimated effective population size at the expansion frontier.

Conclusions:

• Spatial models of population genetics can quantitatively capture organismal evolution.
• This study provides proof of principle for the predictive power of spatial population genetics models.
• The findings have implications for understanding microbial evolution and community dynamics.