center for brain, behavior & evolution

Understanding the natural diversity of behavior, in the lab & in the wild.

 David Crews

David Crews

The Crews lab has made a number of fundamental contributions to understanding how ecological and evolutionary processes interact with gonadal steroids to shape sexual development and adult behavior. One of the lab's current foci is on the mechanisms of environmental sex determination in lizards and turtles. They explore how temperature can alter sex determination by shaping the expression of a variety of steroidogenic enzymes, steroid hormone receptors, and other transcription factors. A second major focus is on how environmental endocrine disruptors can produce trans-generational changes in the development of body, brain and behavior in laboratory rats. There is now evidence that an individual's likelihood of developing health problems is influenced by the environmental conditions of prior generations. This transmission of life experiences across generations represents the newly emerging field of environmental epigenetics.

 

 

 

 Molly Cummings

Molly Cummings

The Cummings lab studies the mechanisms that drive biodiversity in animal communication with an emphasis on visual ecology.  They combine environmental measures, behavioral experiments and molecular approaches to gain an integrative understanding of the sources and targets of selection on animal displays. The lab examines the evolution of (in)conspicuousness in various contexts, including the sexual displays of swordtail fishes, the evolution of aposematic coloration in poison frogs, and the role of polarized light in the camouflage of marine species. In parallel, the lab studies the neural mechanisms underlying female mate choice in swordtails and related species. They use genomic approaches to identify and characterize the functions of genes involved in orchestrating female mating decisions. This analysis lays a foundation for comparative studies of the mechanisms of mate choice.

 

 

 

 Hans Hofmann

Hans Hofmann

The research in Dr. Hofmann's laboratory seeks to understand the molecular and hormonal mechanisms that underlie social behavior and its evolution. African cichlid fishes are an ideal model system to address these questions because of their recent, repeated and rapid radiations that have resulted in hundreds of phenotypically diverse species. Their work uses a broad spectrum of approaches, ranging from ecological studies in the East African Great Lakes to functional genomics using custom-made cDNA microarrays for gene expression profiling in the brain. They also employ hormonal perturbations, neuroanatomical techniques and bioinformatics tools. The lab uses this variety of methods to ask how neuroendocrine regulators of behavior shape and are shaped by ecological and evolutionary factors, such as mating system, conspecific social networks, and the tension between cooperation and conflict. Through such work, the lab aims to identify the molecular building blocks of complex behavior.

 

 

 Uli Mueller

Uli Mueller

The Mueller Lab aims to understand the evolution of organismal interactions, particularly the evolution of mutualisms and the evolution of social conflict and cooperation. A major recent focus has been on the “farming” behavior of fungus growing ants, and the coevolution of farming ants with fungi, plants and rhizosphere microbes. His students have examined a number of other topics, including the role of sleep in honey bees, and neuroanatomical specializations exhibited by different castes of ants within a species. Dr. Mueller admits to an inordinate fondness for any social insect and any mutualistic organism.

 

 

 

 

 Steve Phelps

Steve Phelps

The lab employs a diverse array of approaches, ranging from computational models to the molecular analysis of gene expression. This work is strongly anchored in empirical studies of animal behavior in both the laboratory and field. Using "exotic" rodent models, they focus on the nature and consequences of within- and between-species variation in neuronal gene expression and behavior. For example, they study how individual differences in the neuronal distribution of vasopressin receptors contribute to social attachment, space-use and sexual fidelity in the socially monogamous prairie vole. Another major model concerns the production and perception of advertisement songs in the singing mouse -- a project that includes neuroanatomical studies, field playbacks, and population genetic analysis of song variation. These projects involve substantial field components in both the U.S. and Central America.

 

 

 Jon Pierce-Shimumora

Jon Pierce-Shimumora

The Pierce-Shimomura lab uses the nematode C. elegans to investigate the genetic, neuromodulatory and electrophysiological mechanisms of behavior. Their basic scientific research examines the mechanisms that underlie animal locomotion. Because many genes and pathways share an ancient homology across animal nervous systems, the approach also provides powerful means to screen a variety of therapeutic drugs.  Therapeutic work is centered on identifying causes and potential cures for Down syndrome and Alzheimer's disease, as well as how drugs such as ethanol and anesthetics affect the nervous system. To study the genetic basis of behavior and disease, they combine genetic screens to identify genes involved in a behavior, in vivo electrophysiology and calcium imaging to study the function of identified neurons in lcomotor behavior.

 

 

 Mike Ryan

Mike Ryan

Research in the Ryan laboratory addresses questions concerning the evolution and function of animal behavior. Most of the questions are centered on issues of sexual selection and communication, including parallel investigation of brain, behavior, and evolution. The Ryan lab utilizes a variety of techniques, including natural history studies; phylogenetic reconstruction and comparisons; laboratory experimentation, especially phonotaxis, robotics, and video playbacks; molecular neurobiology; and endocrinology. Although much of the work has centered on frogs and fish, the lab has also studied insects, birds, and mammals. Current studies involve frog-eating bats, blood-sucking flies, swordtails, mollies, túngara frogs, peter's frog, and poison dart frogs.

 

 

 Peter Thomas

Peter Thomas

Dr. Thomas is interested in the endocrine control of reproduction in fishes and other vertebrates, and in the effects of environmental factors such as hypoxia and pollutants on reproductive function. Research is conducted at the Marine Science Institute in Port Aransas and at field sites in the Gulf of Mexico region.  The lab recently discovered a new class of sex steroid receptors in fishes which they have subsequently identified in other vertebrates. The novel receptors are structurally unrelated to nuclear steroid receptors and are located on the surface of cells where they elicit rapid biological responses to steroids by mechanisms not involving gene transcription. Recent studies in fish, amphibians, rodents and humans indicate these receptors mediate steroid regulation of meiosis in oocytes, sperm motility, gonadotropin-releasing hormone (GnRH) secretion and immune function, and are likely involved in the onset of labor in humans and in the progression of breast cancer.

 

 

 Harold Zakon

Harold Zakon

 

Ion channels are fundamental for the workings of the nervous system. The Zakon lab studies the function, regulation, evolution, and adaptations of voltage-gated ion channels.  We primarily study how ion channels contribute to species- and sex differences in the communication signals of electric fishes. Additionally we study adaptive changes in the channels of animals that make channel-targeting toxins to repel predators--such as pufferfish and poison dart frogs—to protect themselves from their own toxins. These are fascinating examples of the correlated evolution of toxin production and self-protection. A second line of research focuses on the origin of evolutionary novelty mainly by investigating genes underlying the parallel evolution of electrosensory systems in the two independently evolved groups of weakly electric fishes.