Genetics and Evolution, Marine Biology, Conservation

B.S. University of Massachusetts—Amherst
Ph.D. University of Connecticut—Storrs

Studies focus on the ecological and evolutionary consequences of genetic diversity in animals and associated microbes.

• Bone-Eating worms

Osedax worms were discovered during February 2002 living on the bones of a whale found at 2891 m depth in Monterey Bay. Osedax females grow complex roots that contain symbiotic bacteria and invade the bone on which these mouthless and gutless worms subsist. Osedax males are microscopic, and they live inside the gelatinous tubes produced by the females. Sex ratios are highly skewed with more than 25 males living in an average female's tube. MBARI press release. 

Vrijenhoek RC, Johnson SB, Rouse GW (2009) A remarkable diversity of bone-eating worms (Osedax; Siboglinidae; Annelida). BMC Biology 7, 74 (13 pages).  URL

Vrijenhoek, RC, Johnson, S, Rouse, GW, 2008. Bone-eating Osedax females and their "harems" of dwarf males are recruited from a common larval pool. Molecular Ecology 17, 4535-4544. URL

Rouse GW, Goffredi SK, Vrijenhoek RC (2004) Osedax: Bone-Eating Marine Worms with Dwarf Males. Science 305: 668-671. URL

• Gene flow and dispersal

Since 1989, research has focused on gene flow and evolutionary relationships of organisms endemic to deep-sea hydrothermal vents and cold water seeps. Most vent-endemic invertebrates have effective modes of dispersal that maintain genetic continuity among populations distributed thousands of kilometers along mid-ocean ridge systems. For some organisms, however, structural aspects of the ridge system (large transform faults and other discontinuities such as the Easter Microplate) result in restricted gene flow or isolation among populations.

Coykendall DK, Johnson SB, Karl SA, Lutz RA, Vrijenhoek RC (2011) Genetic diversity and demographic instability in Riftia pachyptila tubeworms from eastern Pacific hydrothermal vents. BMC Evolutionary Biology 11:  96. URL


Audzijonyte A, Vrijenhoek R (2010) When gaps really are gaps: statistical phylogeography of hydrothermal vent invertebrates. Evolution 64, 2369-2384. URL


Vrijenhoek RC (2010) Genetic diversity and connectivity of deep-sea hydrothermal vent metapopulations. Molecular Ecology 19, 4391-4411. URL


• Molecular Systematics

Research has focused on the the evolutionary histories of vent and seep invertebrates. Phylogenies have been generated for many of the dominant vent taxa including clams, mussels, shrimp, and tubeworms. Present evidence suggests that taxa have had relatively recent origins during the last 100 million years.

Johnson SB, Warén A, Lee R, et al. (2010) Rubyspira, new genus and two new species of bone-eating deep-sea snails with ancient habits. Biological Bulletin 219, 166-177.


Vrijenhoek RC (2009) Cryptic species, phenotypic plasticity, and complex life histories: Assessing deep-sea faunal diversity with molecular markers. Deep Sea Research Part II: Topical Studies in Oceanography 56, 1713-1723.

Little CTS, Vrijenhoek RC (2003) Are hydrothermal vent animals living fossils? Trends in Ecology and Evolution 18: 582-588

• Marine Symbiosis

Long-term research efforts during the past 30 years have focused on the evolutionary and ecological consequences of sexual and asexual reproduction in Mexican poeciliid fish (genus Poeciliopsis). We use a variety of molecular approaches to contrast gene and genomic evolution under the recombinant and non-recombinant breeding systems found in these fish.

Vrijenhoek RC, Parker ED (2009) Geographical parthenogenesis, general purpose genotypes and frozen niche variation. In: Lost Sex (eds. Schön I, Martens K, Van Dijk P), pp. 99-131. Springer Publications, Berlin. PDF


Vrijenhoek, RC, 1998 Animal clones and diversity. Bioscience 48: 617-628.


Vrijenhoek RC (1979) Factors affecting clonal diversity and coexistence. American Zoologist 19, 787-797.

• Conservation Genetics

Several of the sexual species of Poeciliopsis are either endangered or seriously threatened. Field and experimental studies have shown that the competitive ability, disease resistance, developmental stability, growth rate, and fecundity of these fish may be compromised by losses of genetic diversity that accompany population bottlenecks, founder events, and inbreeding.

Vrijenhoek, R. C., 1998 Conservation genetics of freshwater fish. Journal of Fish Biology 53 (Supplement A): 394-412.

• Expeditions
• Southern East Pacific Rise (Dec. 16, 1998 - Jan. 21, 1999)
• Guaymas Hot Vents/21 N (April 4 - 17, 2003)
• Whale Fall (August 2003)
• Easter Microplate (March 12 - April 6, 2005)
• Fiji/Lau Expedition (May 15 - June 3, 2005)

• Publications

• Commonly requested reprints
• Folmer primers
• Vrijenhoek 1979  Frozen Niche Variation
• Quattro et al. 1989 Fitness differences...
• Lively et al. 1990 Red Queen...