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Paige M. Miller
Graduate Program: Ph.D in Environmental Sciences and Biology Program
Field of Study: Evolution and genetics
Academic Background: B.A. in Psychology, Harvard University
I enjoy the outdoors and like to go camping, hiking, and fishing. I also like to scuba dive (in warm waters). Reading is one of my greatest pleasures and has been a lifelong obsession. I am also an animal person. I have 2 cats and 9 cichlid fish now (my husband is a marine ecologist), and cannot wait to move to a home with a yard so I can add dogs to the menagerie.
Theories attempting to explain the evolutionary advantage of sexual reproduction have invoked the benefits of recombination in culling deleterious mutations and providing genetic variation, raw material for natural selection to refine (Rose 1983, Ridley 1993). Without a firmer understanding of the evolution of sex determination, it will be difficult to adequately explain the advantages of sexual reproduction. Research on the origin of sex has been hampered by the long evolutionary history of animals, particularly mammals, obscuring past events behind millions of years of evolution. My project addresses this issue using dioecious flowering plants, Silene latifolia and S. dioica (Caryophyllaceae), as model systems for study of the origins of sex chromosomes. These plants have distinct sex chromosomes (2n=22 + X,Y), the male being heterogametic (XY) (Winge 1923; Westergaard 1940), that may be in an intermediate stage of evolution, still possessing functional genes on a large Y chromosome (Ciupercescu et al. 1990). I am working to identify X and Y chromosome-specific markers using a linkage map, and will use this information to develop sequence characterized amplified region (SCAR) markers. SCAR markers from X and Y-chromosomes and autosomes will then be sequenced to identify the potential autosomal origin of the sex chromosomes, and determine the rate and patterns of evolution o f the sex chromosomes. The second area of my research is to further define the gynoecium suppressor region of the Silene Y chromosome, which determines maleness, using plants that have a natural mutation in this region that causes hermaphroditism. To elucidate the exact form of this mutation, I will use classic breeding studies, cytological analysis (karyotyping), and molecular techniques. This should provide valuable insight into the mechanisms of sex determination in Silene.