American Museum of Natural History

Mark Siddall

Assistant Curator

Ph.D., University of Toronto, 1994 "Fish Blood Parasites and Their Leech Vectors: Biology, Phylogeny and Co-Evolution"

RESEARCH

Dr. Siddall's research focuses on the evolution of leeches and their blood-feeding behavior, as well as on protozoan parasitology in general.

Although much maligned in popular media, leeches have regained considerable interest in the biomedical community. This diverse group of annelid worms once was used in medicine for everything from headaches to cholera. Medicinal leeches remain the tool of choice for alleviating blood clots following microsurgical reattachment of small body parts such as fingers or ears.

Dr. Siddall analyzes the evolutionary patterns of both blood-feeding and non-blood-feeding leeches to determine how they have managed to circumvent the blood-clotting mechanisms of their hosts. Knowledge gained from this research may be used one day to develop anti-coagulants and tumor inhibitors in humans.

He also studies the evolutionary relationships of various protozoan groups-including some that threaten the oyster populations along the Atlantic Coast, and others that cause malaria and giardiasis. Currently, Dr. Siddall and colleagues are completing a project that establishes the origins of relationships among bird, lizard, human, and primate malarias.

Another aspect of his work assesses the genetic diversity of leeches in wild populations decimated by centuries of over-exploitation, to determine their species' level of endangerment.

Recent Significant Publications

Siddall, M. E. "Hirudinea from the Apolobamba in the Bolivian Andes, Including New Species of Helobdella." American Museum Novitates (in press, 2001).

Gelder, S. R., and M. E. Siddall. "Phylogenetic Assessment of the Branchiobdellidae Using 18S rDNA and Mitochontrial Cytochrome c Oxidase Subunit I Characters." Zoology Scripta (in press, 2001).

Siddall, M. E. "On the Cladistic Use of Riboprinting." Cladistics (in press, 2001).

Siddall, M. E. "Transmission of Haemogregarina balli from Painted Turtles to Snapping Turtles Through the Leech Placobdella Ornata." Journal of Parasitology (in press, 2001).

Siddall, M. E. "Computer-Intensive Randomization in Systematics." Cladistics (in press, 2001).

Pol, D., and M. E. Siddall. "Biases in Maximum Likelihood and Parsimony: A Simulation Approach to a Ten-Taxon Case." Cladistics (in press, 2001).