PEET - Bivalves Project: Isognomon

Trainee: John Wilk, Ph.D. Student, University of Illinois at Chicago and Field Museum of Natural History, 2003

The bivalve genus Isognomon is the focus of this Ph.D. dissertation project examining the evolution of developmental pathways and ecophenotypic responses. This investigation uses molecular phylogenetics to reveal the evolutionary relationships between the approximately 24 species that are assumed to be valid and to uncover any cryptic diversity that might exist within the genus. Using these revealed relationships, geometric morphometrics are being used to examine variation in shell shape due to ontogeny and habitat effects between species pairs across this group. These comparisons reveal the evolution of developmental pathways, the evolution of ecophenotypic responses, and other patterns of evolution such as convergence. This research will add to the understanding of the mechanisms of morphological evolution and the processes by which species become distinct from each other and how individuals adapt to the environment around them.

Publications: Wilk, J. A. 2004. Cytochrome oxidase I sequence and morphological variation in Florida Isognomon alatus – implications for systematics and population genetics (poster). World Congress of Malacology, Perth, Australia, 13 July 2004, p. 163.

Wilk, J. A. 2004. Cytochrome oxidase I sequence and morphological variation in Florida Isognomon alatus – implications for systematics and population genetics (poster). American Malacological Society, Sanibel, Florida, 2 August 2004, p. 99.

Wilk, J. A. 2005. Phylogenetics of the genus Isognomon (Bivalvia: Pterioidea): initial findings and cross-isthmus invasions. American Malacological Society / Western Society of Malacologists joint annual meeting, Pacific Grove, California, 27 June 2005, p. 128.

Wilk, J. A. 2006.  Judging an oyster by its cover: differentiating extremely similar allopatric Isognomon species (Bivalvia: Isognomonidae) using geometric morphometric analysis of conchological features (poster). Sigma Xi Graduate Research Forum, University of Illinois at Chicago, 14 April 2006.

Wilk, J. A. 2006. Judging an oyster by its cover: differentiating extremely similar allopatric Isognomon species (Bivalvia: Isognomonidae) using geometric morphometric analysis of conchological features. Midwestern Ecology and Evolution Conference, St. Louis, Missouri, 17-19 March 2006.

Wilk, J. A. 2007. Ecophenotypic variation in the mangrove oyster, Isognomon alatus (Pterioidea: Bivalvia) associated with a tide microhabitat gradient. World Congress of Malacology, Antwerp, Belgium, 19 July 2007, pp. 241-242.

Wilk, J. A. 2007. Judging a mangrove oyster by its cover: differentiating extremely similar allopatric Isognomon species (Pterioidea: Bivalvia) using geometric morphometric analysis of conchological features (poster). World Congress of Malacology, Antwerp, Belgium, 17 July 2007, p. 242.

Wilk, J. A. 2007. Ecophenotypic variation in the flat oyster, Isognomon alatus (Isognomonidae: Bivalvia), across a tide microhabitat gradient (poster). Sigma Xi Graduate Research Forum, University of Illinois at Chicago, 20 April 2006, p. 40.

Wilk, J. 2008. Conchological convergence through intercepting ontogenetics: examining convergent shell shape in allopatric Isognomon species of the sub-genus Melina Philipsson, 1788 (Pterioidea: Bivalvia). American Malacological Society, University of Carbondale, Carbondale, Illinois, 30 June 2008, p. 72.

Wilk, J. 2008. Ecophenotypic variation in the flat tree oyster, Isognomon alatus (Bivalvia: Isognomonidae), across a tidal microhabitat gradient (poster). American Malacological Society, University of Carbondale, Carbondale, Illinois, 1 July 2008, p. 73.

Tëmkin, I. 2005. Evolution of extant pterioidean bivalves (poster).World Summit on Evolution, Universidad San Francisco de Quinto, San Cristobal, Galapagos, Equador, 10 Jun 2005.

Tëmkin, I. 2006. Overcoming incongruence in the phylogeny of the Pterioidea. International Congress on Bivalvia, Universitat Autònoma de Barcelona, Bellaterra, Spain, 26 July 2006, p. 77-78.

Tëmkin, I., and P. M. Mikkelsen. 2003. The systematic status of the pearl oyster genera (Bivalvia: Pteriidae) as inferred from molecules and morphology. American Malacological Society, Special Session: PEET Meets Molluscan Taxonomy, University of Michigan, Ann Arbor, 28 June 2003, p. 58.