We study evolution in natural plant populations, with a particular interest in the evolution of floral traits. The diversity of floral traits in angiosperms is thought to have arisen largely because it plays a primary role in attracting pollinators as effective agents of cross-pollination. We are especially interested in the evolutionary challenges faced by populations when cross-pollination is ineffective or costly. Specifically, current research focuses on three major themes: 1) the dissolution of self-incompatibility polymorphisms in plants; 2) the diversification dynamics of self-incompatibility alleles in Brassicaceae; and 3) the process of floral character displacement when species share pollinators. In each of these areas, we employ molecular analyses of polymorphism, studies in natural populations, and manipulative greenhouse experiments to elucidate the evolutionary processes that maintain or transform genetic diversity in the wild.
Prospective graduate students:
I am accepting graduate students with interests in ecology, evolution, and genetics. Graduate students have the option to work on the lab organism (Leavenworthia), but are also encouraged to explore their own ideas in other interesting systems. Contact me via email at email@example.com to discuss the possibility of joining the lab. Please also see the lab webpage for more information on current lab members and their interests.
Igic B and JW Busch. 2013. Is self-fertilization an evolutionary
dead end? New Phytologist 198:386-397.
Dixon AL, CR Herlihy and JW Busch. 2013. Demographic and population-genetic tests provide mixed support for the abundant centre hypothesis in the endemic plant Leavenworthia stylosa. Molecular Ecology 22:1777-1791.
Herman AC, JW Busch and DJ Schoen. 2012. Phylogeny of Leavenworthia S-alleles suggests unidirectional mating system evolution and enhanced positive selection following an ancient population bottleneck. Evolution 66:1849-1861.
Busch JW and WJ Werner. 2012. Population structure has limited fitness consequences in the highly selfing plant Leavenworthia uniflora (Brassicaceae). International Journal of Plant Sciences 173:495-506.
Busch JW and LF Delph. 2012. The relative importance of reproductive assurance and automatic selection as hypotheses for the evolution of self-fertilization. Annals of Botany 109:553-562.
Busch JW. 2011. Demography, pollination, and Baker’s law. Evolution 65:1511-1513.
Busch JW, S Joly and DJ Schoen. 2011. Demographic signatures accompanying the evolution of selfing in Leavenworthia alabamica. Molecular Biology and Evolution 28:1717-1729.
Busch JW and L Urban. 2011. Insights gained from 50 years of studying the evolution of self-compatibility in Leavenworthia (Brassicaceae). Evolutionary Biology 38:15-27.
Busch JW, CR Herlihy, L Gunn and WJ Werner. 2010. Mixed mating in a recently derived self-compatible population of Leavenworthia alabamica (Brassicaceae). American Journal of Botany 97:1005-1013.
Busch JW, S Joly and DJ Schoen. 2010. Does mate-limitation in self-incompatible species promote the evolution of selfing? The case of Leavenworthia alabamica. Evolution 64:1657-1670.
Schoen DJ and JW Busch. 2009. The evolution of dominance in sporophytic self-incompatibility systems. II. Mate availability and recombination. Evolution 63:2099-2113.
Busch JW, J Sharma and DJ Schoen. 2008. Molecular characterization of Lal2, an SRK-like gene linked to the S-locus in the wild mustard Leavenworthia alabamica. Genetics 178:2055-2067.
Busch JW and DJ Schoen. 2008. The evolution of self-incompatibility when mates are limiting. Trends in Plant Science 13:128-136.
Busch JW. 2006. Heterosis in an isolated, effectively small, and self-fertilizing population of the flowering plant Leavenworthia alabamica. Evolution 60:184-191.
Busch JW. 2005. The evolution of self-compatibility in geographically peripheral populations of Leavenworthia alabamica (Brassicaceae). American Journal of Botany 92:1503-1512.
Busch JW. 2005. Inbreeding depression in self-incompatible and self-compatible populations of Leavenworthia alabamica. Heredity 94:159-165.
Busch JW, M Neiman and JM Koslow. 2004. Evidence for maintenance of sex by pathogens in plants. Evolution 58:2584-2590.