There are somewhere between 2 and 10 million living species on earth – possibly more. What processes create this incredible diversity? The deep and difficult question of how new species form has challenged biologists for a long time. This question is at the heart of my research program. A unifying theme of my work is to understand how an organisms’ behavior generates selection that results in diversification, and how diverse behavior itself evolves under the influence of multiple forms of selection. Behavioral traits are thus the primary phenotypes of interest, but can also be the agents of evolutionary change.
The Braasch Lab addresses fundamental questions about the genomic and developmental basis of major transitions during the course of vertebrate evolution. We study genomic and morphological novelties in vertebrates at the levels of genome structure, gene family dynamics, and gene regulation and combine comparative genomics with analyses of molecular evolution and developmental genetic approaches using zebrafish (Danio rerio), spotted gar (Lepisosteus oculatus) and other fishes as model systems.
I am interested in the gene regulatory networks underlying transdifferentiation and organogenesis during development. I am using weakly electric mormyrid fish and investigating the formation of the larval vs adult electric organ to look into these gene networks. I want to take an evolutionary developmental approach and investigate how the electric organ first developed ancestrally and how modification to the “electric organ” gene network allowed for the diversity in form and function that is seen among mormyroids.
Our research concerns the causes of evolutionary changes in the nervous system and the behavioral consequences of these changes. We are focusing on evolution and detection of pheromones in salamanders.
The application of quantitative methods in ecology and conservation is the principal driver for my dissertation research. I develop hierarchical models to parse out the complexities of ecological systems into processes that can be described using multi-level statistical and mathematical models. I utilize the flexibility of a Bayesian statistical framework and rigorous computer programming to implement hierarchical models. The estimates from these models inform wildlife management, and the model development provides a quantitative framework for future ecological and conservation research.
I am broadly interested in evolution, ecology, and conservation of natural populations. Research in my lab combines genomic tools, mark-recapture methods, and experiments to study how interactions between gene flow, drift, and selection affect population dynamics and diversity patterns. I am especially interested in gaining a mechanistic understanding of genetic rescue, which is the increase in population growth caused by the infusion of new genetic variation, and in implementing this tool in conservation and management.
We are interested in the origin and diversification of novel phenotypic and behavioral traits involved in animal communication signals, as they relate to signal diversity, mate choice, and speciation. Our model system of choice is the mormyrid electric fish, which enables a highly integrative approach to these questions, combining behavior, physiology, developmental biology, population genetics, and genomes.
The goal of our research is to understand how stem cells generate a diverse and complex nervous system using zebrafish as a model system. My laboratory addresses this question focusing on the largest part of the peripheral nervous system – the enteric nervous system (ENS). Our research aims to answer the fundamental question of how the generation of ENS cell lineages is regulated during normal development, in situations that model human disease, and under regenerating conditions. We will not only uncover cellular, genetic, and molecular mechanisms underlying cell fate determination but also contribute to developing therapeutic approaches using stem cells to repair ENS diseases.
My research is in the field of behavioral ecology. I focus on the role of information and uncertainty in various aspects of the ecology and evolution of behavior, including: sexual selection, social behavior, communication, conflict and cooperation, predator-prey interactions, habitat choice and the evolution of adaptive phenotypic plasticity.
My principal research interests involve ecosystem ecology and biogeochemistry, with particular attention to aquatic environments and the movement of water through landscapes. I am especially interested in running waters, wetlands and floodplains because they represent an interface between aquatic and terrestrial ecosystems that are often biologically diverse and productive. I also like to consider ecosystem processes at the landscape or watershed scale, and I prefer to do research that contributes to our understanding of environmental problems or improves our ability to manage ecosystems. In recent years I have increasingly conducted research on the agricultural ecology and the sustainability of crop production for food and biofuel.
Research in my laboratory investigates how social, ecological, and endocrine variables interact during an individual`s early development to influence its subsequent behavior and its reproductive success as an adult.
Work in the Meek lab aims to understand the interactions among molecular ecology, population health and persistence, anthropogenic change, and trait variation, with an emphasis on aquatic systems. Example research projects include examining population differentiation in Chinook salmon using RAD-seq, determining the molecular processes that control steelhead life history trait variation, such as the propensity to migrate, and using next-generation sequencing to understand the interactions between local adaptation and climate change in cold-water fishes. Our lab actively collaborates with resource managers and agency biologists to ensure our work informs management and conservation decisions.
My current research focuses on the systematics and taxonomy of tropical Asian birds using integrative methods (vocalizations, morphology, ecology, and, with collaborators, genetics). Much of my research involves the delimitation of cryptic species of Asian owls and warblers, which is important to understanding biodiversity levels and setting conservation priorities.
My research is at the interface of animal behavior and microbial ecology, exploring how an organism's behavior shapes its microbial communities, and how microbial communities, in turn, influence their host's behavioral phenotype. Specifically, I am studying the socioecological predictors affecting microbiome structure in spotted hyenas, and the functional contributions of various body-site specific microbiomes to hyena behavior, physiology, and fitness.
The Zarnetske Spatial and Community Ecology Lab uses a combination of observational data, experiments, and statistical and theoretical modeling to connect observed patterns of biodiversity and community composition with underlying mechanisms across local to global scales. We aim to understand and predict how the composition and geographic distributions of species and ecological communities are affected by biotic interactions, species invasions, biophysical feedbacks, geodiversity, climate change, and land-use change. A central goal is to understand which species and ecological communities are most sensitive and/or resilient to climate change, and in turn act as "biotic multipliers" of climate change through their outsized impacts on ecological communities.