Welcome to the Michael J. Braun Lab!
- How are speciation processes affected by sexual selection?
- What are the historical and geographic origins of biotic communities occupying major areas of endemism?
- Can we improve captive breeding efforts for endangered species by using genomic surveys to select optimal founders?
- What genomic adaptations are associated with the repeated evolution of nocturnal vision?
Our research focuses on the use of molecular genetic data to enhance our understanding of the origin and maintenance of biological diversity. We often use birds as a model system, but have worked extensively on other organisms. Our current research falls in four areas:
Hybrid zones and speciation– Molecular, morphological, behavioral and experimental approaches are integrated to assess the origin, structure and maintenance of avian hybrid zones within the conceptual framework of speciation.
Molecular phylogenetics– In addition to studying the phylogeny of specific groups of birds, mammals, crocodilians and viruses, we have devoted a good deal of effort to developing new genes that are particularly well suited for use as probes of phylogeny, and am now engaged in Early Bird, an NSF-funded, multi-lab project to assemble the avian tree of life.
Genetic structure and diversity of natural populations– A series of projects examine variation within and among avian populations in relation to biogeographic history, environmental change, life history parameters and conservation concerns. The Red Siskin, Sporagra (Carduelis) cucullata, is a song bird of northern South America that is highly endangered as a result of rampant trapping for the cage bird trade. Demand for this species was largely driven by aviculturalists who were competing to produce red canaries through hybridization with red males in the early to mid-20th century. Despite decades of legal protection trapping still threatens extinction, fueled by a lucrative black market and inadequate enforcement. Fortunately, there is now a comprehensive, international effort to recover this bird in the wild. The many partners include Smithsonian scientists from National Museum of Natural History (NMNH), Conservation Biology Institute (SCBI), and Migratory Bird Center (SMBC) and Venezuelan members from Instituto Venezolano de Investigaciones Cientificas, Parque Zoológico y Botánico Bararida, and conservation NGO PROVITA, as well as universities, businesses, community-based and grassroots organizations, and other NGOs. Project components include extensive field research, conservation genomics, development of an ex situ conservation breeding program, a reintroduction strategy based on SMBC’s innovative “Bird Friendly Coffee” certification program, and education programs aimed at the general public and government. Current research at NMNH is focused on estimating genetic diversity among disjunct colonies of red siskins and developing genomic markers (Ultra Conserved Elements, Microsatellites, Single Nucleotide Polymorphisms) for management of an ex situ captive breeding program through the use of Next Generation DNA Sequencing (NGS) technologies. Key objectives for breeding management are to optimize genetic diversity, propagate important local adaptations, and avoid inbreeding depression. Another priority is to preserve the genetic identity of the species. We are developing a genomic screening assay to carefully select only genetically pure red siskins to include in the breeding program. In summer 2013, we will convene two meetings of conservation experts, architects, and other stakeholders to draft a comprehensive conservation management plan and start designing a new conservation breeding and education center to be constructed at PZBB.
Neotropical biogeography– Regular fieldwork throughout the Neotropics advances our understanding of avian diversity and distribution in this complex region. An important goal of this fieldwork is to build and diversify our genetic resource collection to support comparative molecular research by myself and others. For the past 7 years, my fieldwork has been focused on conducting an in-depth survey of the birds of Guyana. This work has generated a tremendous amount of new information on the distribution, ecology and systematics of the avifauna of the Guianan Shield.
Our research is important because it provides significant new insights into the patterns of biodiversity in nature and the evolutionary processes that generate those patterns. At a fundamental level, improving our understanding of these phenomena makes possible a more profound appreciation of Earth’s biota and humanity’s place within it. At a practical level, knowledge derived from this sort of research is foundational to numerous fields that influence our everyday quality of life, including biomedicine, forensics, conservation biology, and management of natural resources. A good deal of our research is immediately applicable in these fields.
The Braun Lab is affiliated with both the Vertebrate Zoology department of the Smithsonian Institution’s National Museum of Natural History, and the BEES graduate program of the Biology Department at the University of Maryland.