James Hamrick
Regents Professor of Plant Biology
Ph.D. (1970) University of Califonia, Berkeley
Phone: 706-542-1826
Email: hamrick@plantbio.uga.edu
See my Laboratory Home Page
Research Interests
The research emphasis of my lab is on the genetics and evolution of natural plant populations. We particularly focus on the genetic structure of plant populations and on those evolutionary factors that influence the development and maintenance of genetic structure: natural selection, the mating system and pollen and seed dispersal patterns. Our approach is to use genetic markers (allozymes, cpDNA, microsatellites) to estimate rates of gene flow, to describe patterns of matings within populations and to determine the timing and direction of natural selection.
  • Cruse-Sanders, J. M., J.L. Hamrick and J.A. Ahumada. 2005. Consequences of harvesting for genetic diversity in American ginseng (Panax quinquefolius L.): a simulation study. Biodiversity and Conservation 14: 493-504.
  • Dunphy, B.K. and J.L. Hamrick. 2005. Gene flow among established Puerto Rican populations of the exotic tree species, Albizia lebbeck. Heredity 94: 418-425.
  • Otero-Arnaiz, A., A. Casas, J.L. Hamrick and J. Cruse-Sanders. 2005. Genetic variation and evolution of Polaskia chichipe (Cactaceae) under domestication in the Techuacan Valley, central Mexico. Mol. Ecol. 14: 1603-1612.
  • Godt, M.J.W., F. Caplow and J.L. Hamrick. 2005. Allozyme diversity in the federally threatened golden paintbrush, Castilleja levisecta (Scrophulariaceae). Cons. Genet.6: 87-99.
  • Trapnell, D.W. and J.L. Hamrick. 2005. Mating patterns and gene flow in the neotropical epiphytic orchid, Laelia rubescens. Mol. Ecol. 14: 75-84.
  • Dunphy, B.K. and J.L. Hamrick. 2005. Gene flow among established Puerto Rican populations of the exotic tree species, Albizia lebbeck. Heredity 94: 418-425.
  • Godt, M.J.W., F. Caplow and J.L. Hamrick. 2005. Allozyme diversity in the federally threatened golden paintbrush, Castilleja levisecta (Scrophulariaceae). Cons. Genet. 6: 87-99.
  • Trapnell, D.W., J.L. Hamrick and J.D. Nason. 2004. Three-dimensional fine-scale genetic structure of the neotropical epiphytic orchid, Laelia rubescens. Mol. Ecol. 13: 1111-1118.
  • Erickson, D.L., J.L. Hamrick and G.D. Kochert. 2004. Ecological determinants of genetic diversity in an expanding population of the shrub Myrcia cerifera. Mol. Ecol. 13: 1655-1664.
  • Hamrick, J.L. 2004. Response of forest trees to global environmental changes. For. Ecol. and Manag. 197: 323-335.
  • Cruse-Sanders, J.M. and J.L. Hamrick. 2004. Spatial and genetic structure within populations of wild American ginseng (Panax quinquefolius L. Araliaceae). J. Heredity 95: 309-321.
  • Dunphy, B.K., J.L. Hamrick and J. Schwagerl. 2004. A comparison of direct and indirect measures of gene flow in the bat-pollinated tree Hymenaea courbaril in the dry forest life zone of southwestern Puerto Rico. Int. J. Plant Sci. 165: 427-436.
  • Trapnell, D.W. and J.L. Hamrick. 2004. Partioning nuclear and chloroplast variation at multiple spatial scales in the neotropical epiphytic orchid, Laelia rubescens. Mol. Ecol. 13: 2655-2666.
  • Grace, S.L., J.L. Hamrick and W.J. Platt. 2004. Estimation of seed dispersal in an old-growth population of longleaf pine (Pinus palustris) using maternity exclusion analysis. Castanea 69: 207-215.
  • Irwin, A.J., J.L. Hamrick, M.J.W. Godt and P.E. Smouse. 2003. A multiyear estimate of the effective pollen donor pool for Albizia julibrissin. Heredity 90: 187-194.
  • Hufford, K.M. and J.L. Hamrick. 2003. Viability selection at three early life stages of the tropical tree, Platypodium elegans (Fabaceae, Papilionoideae). Evolution 57: 518-526.
  • Nassar, J.M., J.L. Hamrick and T.H. Fleming. 2003. Population genetic structure of Venezuelan chiropterophilous columnar cacti (Cactaceae). Am. J. Bot. 90: 1628-1637.
  • Burke, J.M. and J.L. Hamrick. 2002. Genetic variation and evidence of hybridization in the genus Rhus (Anacardiaceae). J. Heredity 93: 37-41.
  • Jorgensen, S., J.L. Hamrick and P.V. Wells. 2002. Regional patterns of genetic diversity in Pinus flexilis (Pinaceae) reveal complex species history. Am. J. Bot. 89: 792-800.
  • Nassar, J.M., J.L. Hamrick and T.H. Fleming. 2002. Allozyme diversity and genetic structure of the leafy cactus (Pereskia guamacho [Cactaceae]). J. Hered. 93: 193-200.
  • Nason, J.D., J.L. Hamrick and T.H. Fleming. 2002. Historical vicariance and postglacial colonization effects on the evolution of genetic structure in Lophocereus, a Sonoran Desert columnar cactus. Evolution 56: 2214-2226.
  • Dvorak, W.S., J.L. Hamrick, B.J. Furman, G.R. Hodge and A.P. Jordan. 2002. Conservation strategies for Pinus maximinoi based on provenance, RAPD and allozyme information. For. Gen. 9: 263-274.
  • Dalling, J.W., K. Winter, J.D. Nason, S.P. Hubbell, D.A. Murawski and J.L. Hamrick. 2001. The unusual life history of Alseis blackiana: A shade-persistent pioneer tree? Ecology 82: 933-945.
  • Godt, M.J.W., J.L. Hamrick, M.A. Edwards-Burke and J.H. Williams. 2001. Comparisons of genetic diversity in white spruce (Picea glauca) and jack pine (Pinus barksiana) seed orchards with natural populations. Can. J. For. Res. 31: 943-949.
  • Nassar, J.M., J.L. Hamrick and T.H. Fleming. 2001. Genetic variation and population structure of the mixed-mating cactus, Melocactus curvispinus (Cactaceae). Heredity 87: 69-79.
  • Parker, K.C., J. L. Hamrick, A. J. Parker and J.D. Nason. 2001. Fine-scale genetic structure in Pinus clausa (Pinaceae) populations: effects of disturbance history. Heredity 87: 99-113.
  • Apsit, V.J., J.L. Hamrick and J.D. Nason. 2001. Breeding population size of a fragmented population of a Costa Rican dry forest tree species. J. Hered. 92: 415-420.
  • Fleming, T.H., C.T. Sahley, J.N. Holland, J.D. Nason and J.L. Hamrick. 2001. Sonoran desert columnar cacti and the evolution of generalized pollination systems. Ecol. Mono. 71: 511-530.