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David Mark Welch,
Assistant Scientist
The major goal of our research is to understand why sexual recombination is necessary for the evolutionary success of multicellular life– why sex is nearly universal among multicellular eukaryotes and why the vast majority of species that abandon sexual reproduction are rapidly driven to extinction. Despite more than 150 years of attention, these questions remain one of the central mysteries of biology, with broad implications in genetics, ecology, and evolution. Combining aspects of molecular genetics, population genetics, evolutionary genomics, and phylogenetics, our research explores these questions by examining the consequences of long-term asexuality on genome structure and on host immune systems, and by studying the ecological and evolutionary dynamics of sex loss and preservation in populations.
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David Mark Welch's CV >>
Recent Publications:
Mark Welch, D.,
Mark Welch, J.,
Meselson, M., 2008.
Evidence for degenerate tetraploidy in bdelloid rotifers.
Proceedings of the National Academy of Sciences
10.1073/pnas.0800972105.
Meselson, M.
and
D.B. Mark Welch. 2007. Stable heterozygosity?
Science 318: 202-203.
Huber, J.A.,
D.B. Mark Welch,
H.G. Morrison,
S.M. Huse,
P.R. Neal,
D.A. Butterfield, and
M.L. Sogin. 2007.
Microbial population structures in the deep marine biosphere.
Science
318: 97-100.
Suga, K., D.B. Mark Welch, Y. Tanaka, Y. Sakakura, and A. Hagiwara. 2007. Analysis of expressed sequence tags of the cyclically parthenogenetic rotifer Brachionus plicatilis. PLoS ONE 2(8): e671.
Huse, S.M., J.A. Huber, H.G. Morrison, M.L. Sogin, and D.B. Mark Welch. 2007. Accuracy and quality of massively parallel pyrosequencing. Genome Biology 8: R143.
Sogin, M.L., H.G. Morrison, J.A. Huber, D Mark Welch, S.M. Huse, P.R. Neal, J.M. Arrieta, and G.J. Herndl. 2006. Microbial diversity in the deep sea and the underexplored "rare biosphere." Proc. Natl Acad. Sci. 103: 12115–12120.
Mark Welch, D. B. 2005. Bayesian and maximum likelihood analysis of rotifer-acanthocephalan relationships.
Hydrobiologia
546: 47-54.
Mark Welch, D. B. and J. L. Mark Welch. 2005. Genomic approaches to rotifer ecology.
Hydrobiologia
546: 101-108.
Mark Welch, D. B., M. P. Cummings, D. M. Hillis, and M. Meselson. 2004. Divergent gene copies in the asexual class Bdelloidea (Rotifera) separated before the bdelloid radiation or within bdelloid families.
Proc. Natl. Acad. Sci.
(USA) 101: 1622-1625.
Mark Welch, J. L., D. B. Mark Welch, and M. Meselson. 2004. Cytogenetic evidence for asexual evolution of bdelloid rotifers.
Proc. Natl. Acad. Sci.
(USA) 101: 1618-1621.
Mark Welch, D. B. and M. Meselson. 2003. Oocyte nuclear DNA content and GC proportion in rotifers of the anciently asexual Class Bdelloidea.
Biol. J. Linn. Soc. Lond.
79: 85-91.
Non peer reviewed publications:
Mark Welch, D.B., 2002. Rotifera, pp 304–306. In: McGraw-Hill Yearbook of Science & Technology, McGraw-Hill, New York.
Mark Welch, D.B. 2007. Rotifera, In: McGraw-Hill Encyclopedia of Science and Technology, 10th Edition (in press).
Mark Welch, D.B. 2007. Bdelloidea, In: McGraw-Hill Encyclopedia of Science and Technology, 10th Edition (in press).
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