Brian R. Morton, Associate Professor of Biological Sciences and Chair of the Department of Biological Sciences, joined the Barnard faculty in 1995.
Professor Morton's research focuses on two main aspects of the evolution of plastid DNA.
The first is the selective constraints on codon usage across a wide variety of phyla of the plant kingdom. He is attempting to determine how and why selection intensity varies among lineages as well as over time. He is also interested in finding out how selective constraints on codon usage interact with other structural features, such as amino acid composition of proteins and genome organization.
His second major line of research involves an investigation of the nucleotide substitution dynamics of plastid DNA. Professor Morton and his research team are studying the ways in which rate heterogeneity among sites is affected by variation in context, or the composition of nucleotides flanking those sites.
“Selection on the codon bias of chloroplast and cyanelle genes in different plant and algal lineages,” Journal of Molecular Evolution Vol. 46 (1998): 449–459.
“The influence of specific neighboring bases on substitution bias in noncoding regions of the plant chloroplast genome,” with V. M. Oberholzer and M. T. Clegg, Journal of Molecular Evolution Vol. 45 (1997): 227–231.
“The atypical codon usage of the plant psbA gene may be the remnant of an ancestral bias,” with J. A. Levin, Proceedings of the National Academy of Sciences Vol. 94 (1997): 11434–11438.
“Evolution of alcohol dehydrogenase genes in the Palm and Grass families,” with B. S. Gaut and M. T. Clegg, Proceedings of the National Academy of Sciences Vol. 93 (1996): 11735–11739.
“Neighboring base composition and transversion/transition bias in a comparison of rice and maize chloroplast noncoding regions,” Proceedings of the National Academy of Sciences Vol. 92 (1995): 9717–9721.