Phone: (205) 348-2754
Dr. Jeff Lozier received his PhD in the Department of Environmental Science, Policy and Management at the University of California, Berkeley in December 2007, and completed his postdoctoral research in the Department of Entomology at the University of Illinois. He was appointed Assistant Professor at the University of Alabama in 2011.
My research focuses on the use of molecular genetic markers to infer ecological and evolutionary processes in populations of wild organisms. Many of the basic questions in ecology and evolution tie into the fundamental problem of what limits the movement of individuals and the genes they carry at various spatial and temporal scales. Population genetics provides a set of tools to investigate the distribution of genetic variation within and between species to answer questions such as how species form, how to effectively manage threatened populations, or how to track down the patterns of introduction and spread of invasive species. With new genomic tools derived from next generation sequencing we’re also looking into mechanisms of adaptation to environmental pressures. I highlight a few projects below, but for detailed information see my webpage.
Bumble bee decline and conservation genetics
Over the last several years, as part of a collaborative effort at the University of Illinois and Utah State, my colleagues and I conducted large-scale intensive surveys of bumble bee (Bombus) populations throughout the U.S. and identified that several once widespread species have undergone serious reductions in range and abundance. Likely factors in these declines include habitat loss and fragmentation, as well as the introduction of novel disease agents. We determined that the declining species are much more likely to host infections of Nosema bombi, a widespread Microsporidian parasite common in Europe, lending support for the disease hypothesis. Our current work is focusing on using next generation population genetics approaches to test whether N. bombi in North America is likely to be invasive from Europe.
We have also investigated population genetics of six species, and identified that genetic diversity in declining bumble bees is lower than in their healthy relatives, which could provide another possible factor in their declines. Genome-wide analyses using next-generation sequencing data suggests this pattern may be much more complex and in need of further study.
Gene flow in all species appears high at large geographic scales, however, suggesting that dispersal is not severely limited. Most of my research in the near future at UA will focus on applying next generation genetic approaches to North American bumble bees, and will include investigations of phylogeography and speciation, adaptation of populations to challenging environments, and ways to predict the future effects of habitat fragmentation on historically well-connected populations. We do much of this work in mountains of the western US, where we use extreme niche differences across elevations to determine the evolutionary forces shaping intraspecific variation.
Speciation in insects
A fundamental question in evolution is “How do new species arise?” One of my interests is the use of closely related populations or species to better understand the factors that contribute to reproductive isolation of lineages, as well as the extent to which hybridization may occur after divergence. One example focuses on recent isolation among bumble bees with different color patterns in the Bombus bifarius species group, where we are using large scale genomic data sets to determine genetic differences driving color pattern differences and the degree of reproductive isolation among populations. This work also integrates GIS-based approaches with population genetics to investigate geographic causes of speciation by scanning for climatic limitations to dispersal as a possible explanation for strong geographic patterns of genetic isolation.
I’ve also done work with aphid genus Hyalopterus, where I identified three species that are largely associated with feeding on plum, almond, and peach trees in the Mediterranean. Interestingly, all of the species also feed on apricot trees, and the plum and almond associated species also appear to interbreed, but hybrids are found only on apricot. Future research in my lab will focus on fine scale studies of these possible hybrids, which could provide a natural laboratory for identifying factors that may be involved in speciation.
Lozier, J.D. (online early). Revisiting comparisons of genetic diversity in stable and declining species: Assessing genome-wide polymorphism in North American bumble bees using RADtag sequencing. Molecular Ecology DOI: 10.1111/mec.12636.
Lozier, J.D., Koch, J., Strange, J.P. 2013. Landscape heterogeneity predicts gene flow in a widespread polymorphic bumble bee, Bombus bifarius (Hymenoptera: Apidae). Conservation Genetics 14: 1099-110.
Duennes, M. A., Lozier, J.D., Hines, H. M., Cameron, S. A. 2012. Geographical patterns of genetic divergence in the widespread Mesoamerican bumble bee Bombus ephippiatus (Hymenoptera: Apidae). Molecular Phylogenetics and Evolution 64: 219-231.
Lozier, J.D., J.P. Strange, I.J. Stewart, S.A. Cameron. 2011. Patterns of range-wide genetic variation in six North American bumble bee (Apidae: Bombus) species. Molecular Ecology 20: 4870-4888.
Cameron S.A. J.D. Lozier, J.P. Strange, J.B. Koch, N. Cordes, L.F. Solter, T.L. Griswold. 2011. Patterns of widespread decline in North American bumble bees. PNAS 108: 662-667.
Lozier, J.D., N.J. Mills (2009) Ecological niche models and coalescent analysis of gene flow support recent allopatric isolation of parasitoid wasp populations in the Mediterranean. PLoS ONE 6: e5901.
Lozier, J.D., G.K. Roderick, N.J. Mills. 2009. Tracing the invasion history of mealy plum aphid, Hyalopterus pruni (Hemiptera: Aphididae), in North America: a population genetics approach. Biol. Inv. 11: 299-314.
Lozier, J.D., G.K. Roderick, N.J. Mills. 2008. Evolutionarily significant units in Natural enemies: Identifying regional populations of Aphidius transcaspicus (Hymenoptera: Braconidae) for use in biological control of mealy plum aphid. Biol. Control 46: 532-541.
Milton K., J.D. Lozier, and E.A. Lacey. 2008. Genetic structure of an isolated population of mantled howler monkeys (Alouatta palliata) on Barro Colorado Island, Panama. Conserv. Genet. 10: 347-358.
Lozier, J.D., N.J. Mills, G.K. Roderick. 2007. Genetic evidence from mitochondrial, nuclear, and endosymbiont markers for the evolution of host pant associated species in the aphid genus Hyalopterus (Hemiptera: Aphididae). Evolution 61: 1353-1367.