Experimental evolution
Experimental evolution is a powerful research approach for many questions about the evolution of social behavior, multicellularity and predator-prey interactions among microbes.
 
			
                    				   
		    Experimental evolution with microbes features known and revivable ancestors, defined selective environments, frozen storage of viable evolving populations and communities for later analysis, large population sizes and mutation supply, easy replication and tractable molecular analysis of evolutionary change. Evolution experiments with myxobacteria – external page MyxoEEs – have been used to address many evolutionary questions and are summarised at external page myxoee.org.
We examine how variable levels and forms of investment in cooperative behaviors evolve in response to different evolutionary forces.
external page Hidden paths to endless forms most wonderful: ecology latently shapes evolution of multicellular development in predatory bacteria
 M La Fortezza, O Rendueles, H Keller, GJ Velicer. 2022. Communications Biology
 
 external page Allopatric divergence of cooperators confers cheating resistance and limits effects of a defector mutation
 KA Schaal, YTN Yu, M Vasse, GJ Velicer. 2022. BMC Ecology and Evolution
 
 external page Social selection within aggregative multicellular development drives morphological evolution
 M La Fortezza, GJ Velicer. 2021. Proc Roy Soc B
external page Indirect evolution of social fitness inequalities and facultative social exploitation
 Nair RR, F Fiegna, GJ Velicer. 2018. Proc Roy Soc B
external page Social complementation and growth advantages promote socially defective bacterial isolates
 Kraemer SA and GJ Velicer. 2014. Proc Roy Soc B
external page Experimental evolution of selfish policing in social bacteria
 Manhes P and GJ Velicer. 2011. PNAS
external page Evolution of an obligate social cheater to a superior cooperator
 Fiegna F, YTN Yu, SV Kadam and GJ Velicer. 2006.  Nature
external page Competitive fates of bacterial social parasites: persistence and self-induced extinction of Myxococcus cheaters
 Fiegna F and GJ Velicer. 2003. Proc Roy Soc B
external page Developmental cheating in the social bacterium Myxococcus xanthus
 Velicer GJ, L Kroos and RE Lenski. 2000. Nature
external page Loss of social behaviors by Myxococcus xanthus during evolution in an unstructured habitat
 Velicer GJ, L Kroos and RE Lenski. 1998. PNAS
We investigate factors shaping the evolution of developmental phenotypes and interactions.
external page Ribonuclease D Processes a Small RNA Regulator of Multicellular Development in Myxobacteria
 SM Cossey, GJ Velicer, YTN Yu. 2023. Genes
 
 external page Hidden paths to endless forms most wonderful: ecology latently shapes evolution of multicellular development in predatory bacteria
 M La Fortezza, O Rendueles, H Keller, GJ Velicer. 2022. Communications Biology
 
 external page Social selection within aggregative multicellular development drives morphological evolution
 M La Fortezza, GJ Velicer. 2021. Proc Roy Soc B
external page Indirect evolution of social fitness inequalities and facultative social exploitation
 Nair RR, F Fiegna, GJ Velicer. 2018. Proc Roy Soc B
external page Evolution of an obligate social cheater to a superior cooperator
 Fiegna F, YTN Yu, SV Kadam and GJ Velicer. 2006.  Nature
external page Developmental cheating in the social bacterium Myxococcus xanthus
 Velicer GJ, L Kroos and RE Lenski. 2000. Nature
external page Loss of social behaviors by Myxococcus xanthus during evolution in an unstructured habitat
 Velicer GJ, L Kroos and RE Lenski. 1998. PNAS
Negative and positive frequency dependence of social fitness readily evolves among closely related conspecifics.
external page Predatory bacteria select for sustained prey diversity
 RR Nair, GJ Velicer. 2021. Microorganisms  
external page Experimental evolution of selfish policing in social bacteria
 Manhes P and GJ Velicer. 2011. PNAS
external page Sociobiology of the myxobacteria
 Velicer GJ and M Vos. 2009. Annual Review of Microbiology
external page Evolution of an obligate social cheater to a superior cooperator
 Fiegna F, YTN Yu, SV Kadam and GJ Velicer. 2006.  Nature
external page Competitive fates of bacterial social parasites: persistence and self-induced extinction of Myxococcus cheaters
 Fiegna F and GJ Velicer. 2003. Proc Roy Soc B
external page Developmental cheating in the social bacterium Myxococcus xanthus
 Velicer GJ, L Kroos and RE Lenski. 2000. Nature
We are interested in how the genotype-phenotype networks of myxobacterial social/developmental traits are structured and evolve in response to various evolutionary forces.
external page Antagonistic, synergistic, and social pleiotropy in microbial cheaters
 P Manhes, KA Schaal, GJ Velicer. 2022. bioRxiv
external page Indirect evolution of social fitness inequalities and facultative social exploitation
 Nair RR, F Fiegna, GJ Velicer. 2018. Proc Roy Soc B
external page Parallel emergence of negative epistasis across experimental lineages
 Zee PC and GJ Velicer. 2017. Evolution
external page Pervasive, yet idiosyncrative, epistatic pleiotropy during adaptation in a behaviourally complex microbe
 Zee PC, J Liu and GJ Velicer. 2017. Journal of Evolutionary Biology
external page Evolution by flight and fight: diverse mechanisms of adaptation by actively motile microbes
 Rendueles O and GJ Velicer. 2017. The ISME Journal
external page Rapid and widespread de novo evolution of kin discrimination
 Rendueles O, PC Zee, I Dinkelacker, M Amherd, S Wielgoss and GJ Velicer. 2015. PNAS
external page A shift from magnitude to sign epistasis during adaptive evolution of a bacterial social trait
 Zee PC, H Mendes-Soares, YTN Yu, H Keller, SA Kraemer, S Ossowski, K Schneeberger and GJ Velicer. 2014. Evolution
external page Developmental cheating in the social bacterium Myxococcus xanthus
 Velicer GJ, L Kroos and RE Lenski. 2000. Nature
external page Loss of social behaviors by Myxococcus xanthus during evolution in an unstructured habitat
 Velicer GJ, L Kroos and RE Lenski. 1998. PNAS
Motility is fundamental to the social lives of myxobacteria. We ask how the motility behaviors and systems of Myxococcus evolve in response to different forms of selection.
external page Hidden paths to endless forms most wonderful: Complexity of bacterial motility shapes diversification of latent phenotypes
 O Rendueles, GJ Velicer. 2020. BMC Evolutionary Biology
 
external page Evolution by flight and fight: diverse mechanisms of adaptation by actively motile microbes
 Rendueles O and GJ Velicer. 2017. The ISME Journal
external page Experimental evolution of a microbial predator’s ability to find prey
 Hillesland KL, GJ Velicer and RE Lenski. 2009. Proc Roy Soc B
external page Evolution of novel cooperative swarming in the bacterium Myxococcus xanthus
 Velicer GJ and YTN Yu. 2003. Nature
external page Loss of social behaviors by Myxococcus xanthus during evolution in an unstructured habitat
 Velicer GJ, L Kroos and RE Lenski. 1998. PNAS
Kin discrimination readily evolves in experimental populations of microbes in a variety of forms.
external page Indirect evolution of social fitness inequalities and facultative social exploitation
 Nair RR, F Fiegna, GJ Velicer. 2018. Proc Roy Soc B
external page Evolution by flight and fight: diverse mechanisms of adaptation by actively motile microbes
 Rendueles O and GJ Velicer. 2017. The ISME Journal
external page Rapid and widespread de novo evolution of kin discrimination
 Rendueles O, PC Zee, I Dinkelacker, M Amherd, S Wielgoss and GJ Velicer. 2015. PNAS
Social and multicellular phenotypes often evolve latently.
external page Hidden paths to endless forms most wonderful: ecology latently shapes evolution of multicellular development in predatory bacteria
 M La Fortezza, O Rendueles, H Keller, GJ Velicer. 2022. Communications Biology
 
 external page Allopatric divergence of cooperators confers cheating resistance and limits effects of a defector mutation
 KA Schaal, YTN Yu, M Vasse, GJ Velicer. 2022. BMC Ecology and Evolution
external page Hidden paths to endless forms most wonderful: Parasite-blind diversification of host quality
 L Freund, M Vasse, GJ Velicer. 2021. Proc Roy Soc B
 
 external page Hidden paths to endless forms most wonderful: Complexity of bacterial motility shapes diversification of latent phenotypes
 O Rendueles, GJ Velicer. 2020. BMC Evolutionary Biology
 
external page Indirect evolution of social fitness inequalities and facultative social exploitation
 Nair RR, F Fiegna, GJ Velicer. 2018. Proc Roy Soc B
external page Pervasive, yet idiosyncrative, epistatic pleiotropy during adaptation in a behaviourally complex microbe
 Zee PC, J Liu and GJ Velicer. 2017. Journal of Evolutionary Biology
external page Rapid and widespread de novo evolution of kin discrimination
 Rendueles O, PC Zee, I Dinkelacker, M Amherd, S Wielgoss and GJ Velicer. 2015. PNAS
external page Non-adaptive processes can create the appearance of facultative cheating in microbes
 Smith J, JD van Dyken and GJ Velicer. 2013. Evolution
external page Developmental cheating in the social bacterium Myxococcus xanthus
 Velicer GJ, L Kroos and RE Lenski. 2000. Nature
We investigate the molecular mechanisms of some evolutionary outcomes that emerge in experimental populations.
external page Bacterial predator-prey coevolution selects on virulence-associated prey defenses
 Nair RR, Vasse M, Wielgoss S, Sun L, Yu YN, Velicer GJ. 2019. Nature Communications
external page Evolution by flight and fight: diverse mechanisms of adaptation by actively motile microbes
 Rendueles O and GJ Velicer. 2017. The ISME Journal
external page Rapid and widespread de novo evolution of kin discrimination
 Rendueles O, PC Zee, I Dinkelacker, M Amherd, S Wielgoss and GJ Velicer. 2015. PNAS
external page A shift from magnitude to sign epistasis during adaptive evolution of a bacterial social trait 
 Zee PC, H Mendes-Soares, YTN Yu, H Keller, SA Kraemer, S Ossowski, K Schneeberger and GJ Velicer. 2014. Evolution
external page Adaptive evolution of an sRNA that controls Myxococcus development
 Yu YTN, X Yuan and GJ Velicer. 2010. Science
external page Novel transcriptome patterns accompany evolutionary reversion of defective social development in the bacterium Myxococcus xanthus
 Kadam SV, S Wegener-Feldbrügge, L Søgaard-Andersen and GJ Velicer. 2008.  Molecular Biology and Evolution
external page Comprehensive mutation identification in an evolved bacterial cooperator and its cheating ancestor
 Velicer GJ, G Raddatz, H Keller, S Deiss, C Lanz, I Dinkelacker and SC Schuster. 2006. PNAS
external page Evolution of novel cooperative swarming in the bacterium Myxococcus xanthus
 Velicer GJ and YTN Yu. 2003. Nature
external page Rescue of social motility lost during evolution of Myxococcus xanthus in an asocial environment
 Velicer GJ, RE Lenski and L Kroos. 2002. Journal of Bacteriology
We use experimental evolution to investigate how predation by and of myxobacteria shapes microbial communities.
external page Bacterial predation of a fungal wheat pathogen: Prelude to experimental evolution of enhanced biocontrol agents
 SA Eisner, F Fiegna, BA McDonald, GJ Velicer. 2023. Plant Pathology
 
 external page Hidden paths to endless forms most wonderful: ecology latently shapes evolution of multicellular development in predatory bacteria
 M La Fortezza, O Rendueles, H Keller, GJ Velicer. 2022. Communications Biology
 
 external page Predatory bacteria select for sustained prey diversity
 RR Nair, GJ Velicer. 2021. Microorganisms
external page Bacterial predator-prey coevolution selects on virulence-associated prey defenses
 Nair RR, M Vasse, S Wielgoss, L Sun, Y-TN Yu, GJ Velicer. 2019. Nature Communications
external page Experimental evolution of a microbial predator’s ability to find prey
 Hillesland KL, GJ Velicer and RE Lenski. 2009. Proc Roy Soc B
external page Bacterial predators
 Velicer GJ and H Mendes Soares. 2009. Current Biology
external page Evolution by flight and fight: diverse mechanisms of adaptation by actively motile microbes
 Rendueles O and GJ Velicer. 2017. The ISME Journal
external page Evolution of an obligate social cheater to a superior cooperator
 Fiegna F, YTN Yu, SV Kadam and GJ Velicer. 2006.  Nature
external page Evolution of novel cooperative swarming in the bacterium Myxococcus xanthus
 Velicer GJ and YTN Yu. 2003. Nature
external page Mutation rate and effective population size of the model cooperative bacterium Myxococcus xanthus
 S Wielgoss, JD Van Dyken, GJ Velicer. 2024. Genome Biology and Evolution
external page Bacterial predator-prey coevolution accelerates genome evolution and selects on virulence-associated prey defences.
 Nair RR, Vasse M, Wielgoss S, Sun L, Yu YN, Velicer GJ. 2019. Nature Communications
external page Group formation: on the evolution of aggregative multicellularity
 M La Fortezza, KA Schaal, GJ Velicer. 2022. The evolution of multicellularity
 
external page Evolution: Bacterial territoriality as a byproduct of kin discriminatory warfare
 Velicer GJ and J Plucain. 2016. Current Biology
external page How do microbial populations and communities function as model systems?
 O’Malley MA, M Travisano, GJ Velicer and JA Bolker. 2015. The Quarterly Review of Biology
Whence comes social diversity? Ecological and evolutionary analysis of the myxobacteria
 Velicer GJ, H Mendes-Soares and S Wielgoss. 2014. In Myxobacteria: Genomics and Molecular Biology, P. Higgs and Z. Yang eds. Horizon Scientific Press.
external page Sociobiology of the myxobacteria
 Velicer GJ and M Vos. 2009. Annual Review of Microbiology
Why cooperate? The ecology and evolution of myxobacteria
 Velicer GJ and KL Hillesland. 2007. In Myxobacteria: Multicellularity and Differentiation, D. Whitworth, editor.  American Society for Microbiology Press.
external page Strategies of microbial cheater control
 Travisano M and GJ Velicer. 2004. Trends in Microbiology
external page Social strife in the microbial world
 Velicer GJ 2003. Trends in Microbiology
external page Experimental social evolution with Myxococcus xanthus
 Velicer GJ and KL Stredwick. 2002. Antonie van Leeuwenhoek
external page Games microbes play
 Lenski RE and GJ Velicer. 2000. Selection