Some marine fishes that bear light organs harboring symbiotic luminous bacteria. Clockwise from the upper left the fishes are: Chlorophthalmus nigromarginatus, Physiculus japonicus, Acropoma japonicum, Caelorinchus hubbsi, and, at the center, Aulotrachichthys prosthemius.
Photographs by A. Fukui. |
Professor Paul Dunlap and post-doctoral fellow Jennifer Ast, together with Japanese colleagues, have demonstrated that luminous marine bacteria have not cospeciated with the animals that harbor them in bioluminescent, light-organ symbioses. Their findings, based on an extensive sampling of deep- and shallow-water fishes from east and southeast Asia, contradict the long-held view that bioluminescent symbioses are highly specific, exclusive associations reflecting genetic selection and symbiont-host coevolutionary interactions.
Instead, their work reveals that bioluminescent symbioses are less species specific than previously thought and that in many cases the associations are non-exclusive, with individual host fish harboring two species of luminous bacteria. Furthermore, detailed phylogenetic analyses of these associations demonstrate that the bacteria have not diverged evolutionarily in concert with their host fishes. The implication of their work is that patterns of bioluminescent symbiont-host affiliation observed in nature are likely to arise from a congruence in the environmental distributions of the individual species of bacteria and the animals with which they are symbiotic, not from species-specific genetic selection and coevolution.
Their paper, "Phylogenetic analysis of host-symbiont specificity and codivergence in bioluminescent symbioses" was recently published in the October 2007 journal Cladistics. |
Thore Bergman
Robert Denver
Thomas Duda Jr
Paul Dunlap
John Lehman
Margaret Liu
Philip Myers
Ronald Nussbaum
Robert Payne
Elizabeth Tibbetts
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EEB 433: Ornithology
During the lecture, students have the opportunity to learn about many unique features of birds. In the lab, students have the opportunity to learn about birds by using museum specimens, and by observing birds on field trips.
EEB 436: Woody Plants: Biology and Identification
Ecology, systematic and identification of trees, shrubs, and vines are studied in weekly field trips to diverse Michigan ecosystems--including upland, wetland, and floodplain forests. Lectures focus on glacial landscape history, biogeography, and ecology of Michigan forests.
EEB 438: Biology of Mollusks
An introduction to the biology of mullusks. Lectures on classification, natural history and ecology, functional morphology, development, cytology, elementary physiology, medical malacology, and evolution. Laboratory and field work on identification of local snails and clams and their ecology.
EEB 440: Biology of Fishes
Lectures cover many aspects of the biology of lower vertebrates known as fishes, including evolution, physiology, functional morphology, phylogeny, biogeography, ecology, and reproduction.
EEB 441: The Biology of Fishes Laboratory
This lab provides an introduction to field methods used in fish biology and fisheries, and examines the diversity of the Michigan ichthyofauna and major groups of fishes.
EEB 442: Biology of Insects
Emphasis on living animals and evolution. Embryology, development, and molting; elementary physiology, ecology, genetics and behavior, and functional external and internal morphology; and geological history. Classification of adults and immatures.
EEB 450: Biology of Amphibians and Reptiles
Lectures on the evolution, behavior, ecology, and life history of amphibians and reptiles. Laboratory exercises and field trips emphasize indentification, life history, adaptations, and field methods.
EEB 451: Biology of Mammals
Evolution, distribution, ecology, behavior, anatomy, and classification of mammals, with emphasis on North American species.
EEB 463: Neotropical Plant Families
The course introduces students to generic-level organization of 25 neotropical plant families. Families covered are (1) ecologically widespread and abundant in the neotropics or (2) of taxonomic or economic significance.
Meetings include lectures on comparative morphology, anatomy, and ecological /economic significance of families and their included genera, and a laboratory during which students examine dried specimens.
A field trip to Missouri Botanical Garden in Missouri is included.
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Organismal biology involves the analysis of physiology, morphology, and behavior of individuals, how these characteristics interact with the environment, and how they differ among organisms within a species and among species. Thus, many organismal biologists also have a strong ecological and/or evolutionary perspective in their research program.
