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- Worms in space |
Phylogenetics, the study of the evolutionary relationships of organisms, is an important focus of research by faculty in the Ecology and Evolution Group in University of Pittsburgh Department of Biological Sciences. At the most fundamental level, phylogenies give us the answer to the question "what is it?" Some examples of phylogenetic questions include "are whales mammals or fish?", and "are birds are really a specialized group of dinosaurs?" In recent years, however, biologists have come to realize that the characteristics that organisms possess are often explained by their phylogenetic history, and that the evolution of species and their biochemical, physiological, anatomical, behavioral, and ecological traits cannot be fully explained without knowing their phylogeny. With this realization, and with the advent of new molecular techniques and computer analytical methods for reconstructing phylogenetic trees, there has been an explosion in the study and use of phylogenies. Phylogenies are now becoming applied to more and more areas of biology, including such diverse topics as community ecology, molecular studies of development, functional anatomy, and population genetics. Phylogenies are also being applied to very practical questions, such as identifying new diseases and their sources of transmission to humans. Research on phylogenetics at the University of Pittsburgh involves a variety of organisms, types of data, and questions. Dr. Anthony Bledsoe focuses on the use of cladistic analysis to infer the phylogeny of two important groups of Neotropical passerine birds -- the ovenbirds (Furnariinae) and the tapaculos (Rhinocryptidae) -- based on a combination of myological, molecular, and behavioral data. A second research focus involves the use of phylogenetic methods to study the mechanisms involved in evolutionary reduction and loss of tendon ossification in woodcreepers (Dendrocolaptinae). Pittsburgh Bacteriophage Institute members Drs. Graham Hatfull, Roger Hendrix and Jeffrey Lawrence are comparing the genomic sequences of a diverse group of dsDNA bacteriophages. This research has shown that a major component of their evolution is driven by horizontal exchange of genes between phages. This means that their history cannot be described as a conventional phylogenetic tree but rather as a 'phylogenetic reticulum.' As it becomes clear that the same is true (albeit to a lesser degree) of cellular microbes, phages present a valuable opportunity for developing new analytical methods for describing their relationships and history. |
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