Ecology/Evolution Scientific Symposium at the SACNAS National Conference

The Society of Systematic Biologists (SSB) and BEACON have collaborated to organize a scientific symposium at the Society for the Advancement of Chicanos/Hispanics and Native Americans in Science (SACNAS) national conference in San Antonio, Texas, on October 11th, 2018 (10:30AM-12:00PM, Room 225B). The symposium title is “It’s Complicated: The Ecology and Evolution of Microbes and Their Hosts.”

Host-microbe interactions are ubiquitous and often drive evolution. Microbial parasites or pathogens harm hosts, whereas other host-associated microbes are beneficial or even necessary for host health. Diverse scientists at the forefront of the ecology and evolution of host-microbe interactions will provide a synthetic perspective of research on this important topic.


  • Connie Rojas, PhD Candidate – Michigan State University
  • Luis Zaman, PhD – LSA Collegiate Postdoctoral Fellow, University of Michigan
  • Lisa Barrow, PhD – NSF Postdoctoral Fellow, University of New Mexico
  • Kat Milligan-Myhre, PhD – Assistant Professor University of Alaska Anchorage

SACNAS is a national organization focused on increasing the proportions of underrepresented minorities in science, technology, engineering, and math (STEM) fields. It is the largest multicultural and multidisciplinary STEM diversity organization in the country. In 2017, the National Conference was attended by 3,845 scientists from diverse backgrounds, with 77% of the participants members of ethnic/racial groups that are significantly underrepresented in STEM fields.

Many people may not realize the complicated and often important relationships occurring all around (and inside!) us with microbes and their hosts. As a result of attending our scientific symposium session, attendees will learn about: (1) exciting, recent advances in science research that illuminate how microbes can drive the ecology and evolution of their hosts; (2) the questions and approaches for studying host-microbe and host- parasite interactions; (3) career options within ecology and evolution from presenters at diverse career stages;  and (4) the central role of ecology and evolution to the life sciences. Read the abstracts, below, for more details about each talk.

In addition to the scientific symposium, BEACON and SSB are also sponsoring a day-long Ecology/Evolution field trip on October 13th to Mitchell Lake Audubon Center and the San Antonio Zoo. The symposium and field trip were co-organized by Eve Humphrey, Maurine Neiman, and Alexa Warwick, with support from the Society for the Study of Evolution Diversity Committee and Education and Outreach Committee. The speakers, organizers, and other attendees will also participate in an Ecology/Evolution session of “Conversations with Scientists” to share scientific career options on October 11th (5:45-7:15PM, Room 221C). If you’ll be at SACNAS 2018, we hope to see you at one or all of these events!

Connie Rojas – Host and Ecological Traits Shape the Structure, Function, and Diversity of the Gut Microbiome in Wild Spotted Hyenas

Animal bodies harbor complex microbial communities, hereafter termed microbiota, that exert profound effects on their physiology, behavior, and evolution. In the mammalian gastrointestinal tract, resident microbes are known to synthesize essential vitamins, supply their host with energy released from the fermentation of indigestible carbohydrates, competitively exclude pathogens, and promote immune system and tissue development. In spotted hyenas (Crocuta crocuta) meerkats (Suricata suricatta), and ring-tailed lemurs (Lemur catta), microbiota inhabiting scent-gland secretions co-vary with the gland’s odorous metabolite profiles and contain well-documented odor producers, indicating they likely contribute to their host’s chemical signaling behaviors. Furthermore, in four species of insectivorous bats, bacteria isolated from the skin exhibit anti-fungal properties against the causal agent (Pseudogymnoascus destructans) for white-nose syndrome, suggesting a beneficial role of these microbes in pathogen defense. However, despite the importance of the microbiota, we know little about the forces shaping its structure and function, especially in wild animal populations. Here, I use 16S rRNA gene sequencing technologies to a) survey the gut microbiota of wild spotted hyenas and b) investigate the host social and ecological factors affecting the gut microbiota. Specifically, I assay if gut microbiota diversity and structure vary with hyena age, reproductive state, group size, and temperature and precipitation. Overall, this research will contribute to our understanding of the ways a host shapes its microbial communities, and how microbial communities, in turn, influence their host’s behavioral phenotype. In this talk I will also share a bit about my journey as a scientist from the perspective of a Latina first-generation college student and daughter of immigrant parents.

Dr. Luis Zaman –  Experimenting with Digital and Microbial Evolution

My path to evolutionary biology was unusual. I started as a computer scientist and ended up working in a wet lab with microbes and viruses. I’ll talk about how I ended up where I am, what I’m doing now, and why disciplined and undisciplined science are important in research.





Dr. Lisa Barrow – Variable Host Susceptibility and Enigmatic Parasite Distributions: Insights from Museum Collections and Genomics of Avian Haemosporidians

There are several outstanding questions in ecology and evolution of host-parasite interactions. Why do host species vary so drastically in their susceptibility to parasites? How localized or widespread are different parasites? What are the environmental and host range limits to parasite distributions? These questions are particularly important given the predicted influence of climate change on species distributions and the potential for emerging infectious diseases. Avian haemosporidians are intracellular parasites that infect birds across the globe, sometimes with devastating consequences. Together with multi-institution, student-driven teams, we have been tackling two complex avian haemosporidian systems in Peru and New Mexico, USA. Using molecular and microscopic screening of extensive museum collections, we found that ~35% of birds are infected. In Peru, we screened nearly 4,000 birds representing 40 families and 523 species. After accounting for several environmental, life history, and ecological predictors of infection, we found that host phylogeny explains substantial variation in infection rate. In other words, susceptibility is deeply conserved across the avian tree, and is likely related to conserved aspects of the immune system. In New Mexico, we sampled avian haemosporidian communities in three mountain ranges to better understand the limits to parasite distributions. Haemosporidian communities exhibit structure on fine spatial scales, with most lineages occurring in a single mountain range, but a few widespread generalists infecting multiple host species. Ongoing work incorporating new genomic methods is improving estimates of the host and environmental range limits of haemosporidians, providing important baselines for identifying potential host switches or range expansions.

Dr. Kat Milligan-Myhre – Use of an Evolutionary Model to Determine the Role of Host Genetic Background on Microbiota

Microbiota are the microbes that live in and on a host. Disruption of the microbiota can lead to painful inflammation in the host, which can become chronic, as in the case of inflammatory bowel disease. Our lab focuses on the role the host genes play on the relationship between the microbiota and their host. Thus, we adapted the evolution and biomedical model organism, threespine stickleback fish (Gasterosteus aculeatus), for host-microbe studies. Stickleback are ideal for these studies due to their large family sizes, genetic variation within and between populations that is similar to human genetic variation within and between populations, and the tools available to study these interactions. We compared the development and behavior in fish raised germ free, with conventional microbiota, with mock communities of up to eight microbiota members, or with microbiota disrupted by antibiotic or environmental contaminants. We found that the populations varied in their response to these manipulations, indicating that the genetic variation between the populations contributed greater to the relationship between microbes and the host than the variation within the populations. We will use these results as a basis for future studies to identify the critical windows in development in which disruptions to gut microbiota result in short- and long-term consequences to host health, and determine the extent to which the host genetic background contributes to the ability of healthy gut microbial communities influence to fitness.

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