Ecology and Evolutionary Biology

Ecology and Evolutionary Biology

Doctoral Program

EEB Series Seminar: Dr. Michelle Lawing

Dr. Michelle Lawing, Department of Ecosystem Science & Management, Texas A&M University

Title: “Null models for the ecometric study of trait-climate correlations at continental scales”

Abstract:   The sorting of species along climatic gradients based on traits is a key topic to understanding the impacts of global climatic change in the past, present, and future, as well as the fundamental processes that link ecology and evolution. Trait-based sorting is a complex process involving geographic range changes, selection, extinction, and evolution and requires integration of data from biogeography, phylogenetics, functional analysis, paleontology, and environmental science. Because ecometric analyses are conducted at large spatiotemporal scales, their predictive power is based on statistical correlations whose null distributions have heretofore been largely unstudied. We addressed this problem by constructing null models for the geographic distribution of trait means for North American mammals. We demonstrated 1) extant mammalian assemblage-level traits are geographically sorted along climatic gradients, 2) patterns do not arise spuriously from random, spatial or phylogenetic processes, and 3) traits may be measured in fossil assemblages to reconstruct paleoenvironments.

EEB Series Seminar: Dr. Michelle Lawing

Dr. Michelle Lawing, Department of Ecosystem Science & Management, Texas A&M University

Title: “Null models for the ecometric study of trait-climate correlations at continental scales”

Abstract:   The sorting of species along climatic gradients based on traits is a key topic to understanding the impacts of global climatic change in the past, present, and future, as well as the fundamental processes that link ecology and evolution. Trait-based sorting is a complex process involving geographic range changes, selection, extinction, and evolution and requires integration of data from biogeography, phylogenetics, functional analysis, paleontology, and environmental science. Because ecometric analyses are conducted at large spatiotemporal scales, their predictive power is based on statistical correlations whose null distributions have heretofore been largely unstudied. We addressed this problem by constructing null models for the geographic distribution of trait means for North American mammals. We demonstrated 1) extant mammalian assemblage-level traits are geographically sorted along climatic gradients, 2) patterns do not arise spuriously from random, spatial or phylogenetic processes, and 3) traits may be measured in fossil assemblages to reconstruct paleoenvironments.

EEB Series Seminar: Dr. Scott Egan

Dr. Scott Egan, Department of Biosciences, Rice University

Title:  “Ecological speciation among herbivorous insect populations”

Abstract: Speciation describes the evolutionary process by which new biological species arise.  Understanding the mechanisms contributing to this process is a fundamental question in evolutionary biology. One form of speciation, termed ecological speciation, describes the process by which ecologically based divergent selection between environments leads to the evolution of reproductive barriers between populations. Research on this topic is naturally interdisciplinary and I use a combination of approaches, including field experiments, observations of natural history, lab-based behavioral assays, and genetic and genomic techniques, to better understand how new species evolve in response to divergent selection. Using data from multiple study systems, including Cynipid gall wasps, Chrysomelid leaf beetles, and Tephritid fruit flies, I will present evidence of the critical and diverse role that ecologically driven divergent natural selection can play in the evolution and speciation of plant-feeding insects.

EEB Series Seminar: Dr. Scott Egan

Dr. Scott Egan, Department of Biosciences, Rice University

Title:  “Ecological speciation among herbivorous insect populations”

Abstract: Speciation describes the evolutionary process by which new biological species arise.  Understanding the mechanisms contributing to this process is a fundamental question in evolutionary biology. One form of speciation, termed ecological speciation, describes the process by which ecologically based divergent selection between environments leads to the evolution of reproductive barriers between populations. Research on this topic is naturally interdisciplinary and I use a combination of approaches, including field experiments, observations of natural history, lab-based behavioral assays, and genetic and genomic techniques, to better understand how new species evolve in response to divergent selection. Using data from multiple study systems, including Cynipid gall wasps, Chrysomelid leaf beetles, and Tephritid fruit flies, I will present evidence of the critical and diverse role that ecologically driven divergent natural selection can play in the evolution and speciation of plant-feeding insects.

EEB Series Seminar: Dr. Sarah Hamer

Dr. Sarah Hamer, Department of Veterinary Integrative Biosciences, Texas A&M University College of Veterinary Medicine

Title:  “Chagas disease ecology at the intersection of human, animal, and vector populations”

Abstract: The maintenance of vector-borne zoonotic pathogens in nature is often sustained by cryptic transmission among wildlife reservoirs with occasional spillover to humans.  I will present my lab’s research program on the ecology of Chagas disease, a significant heart disease and cause of death in humans and dogs across Latin America that is increasingly recognized in the southern United States. The disease is caused by infection with a protozoan parasite (Trypanosoma cruzi) that is spread by bloodfeeding Triatomine ‘kissing’ bugs.  Our citizen science program is empowering the public and medical community and has resulted in the submission of over 1800 kissing bugs from across the southern states; these bugs are characterized by over 60% infection prevalence. We are comparing parasite strains that circulate among bugs and various wildlife species to those we have isolated from dogs that died of Chagas cardiomyopathy. In contrast to current media hype about invasion across the border, I will discuss the endemicity of the components of the Chagas pathosystem in the southern states.