Joel Cracraft

Joel Cracraft

Abstract

Species as Taxa: The Units of Biological Diversity and Conservation

Species are commonly units of conservation action, but there is considerable difference of opinion over what is a species. Different species concepts result in fundamentally different approaches to understanding pattern and process in nature.

The species debate within conservation biology comes down to differences of opinion by those, mostly systematists, who advocate a species concept something near a phylogenetic species concept (PSC), and those, mostly population biologists and geneticists, who adhere to the biological species concept (BSC) but rarely use it to discriminate what we might call evolutionary (taxonomic) diversity.

The debate over units is clarified by realizing that (1) species are taxa, and as such, (2) are underpinned by a formal historical nomenclatural foundation, which other species-like "units" (such as "evolutionary significant units") do not have, and therefore (3) conservation biology will be better served by allying itself with formal systematics rather than adopting terminology not grounded at all in taxonomy. Genetic data are extremely important in conservation biology for many reasons. Nevertheless, to a systematist trying to individuate species taxa in nature, genetic data are just another form of evidence. Because the BSC places so much emphasis on genetic phenomena such as hybridization and reproductive isolation, use of that concept has confounded reconstructing history, which ironically leads to misinterpretations of the genetic data. Species concepts do constrain the way we see the world .

Biography

Joel Cracraft is Curator-in-Charge of the Department of Ornithology, American Museum of Natural History. He received his Ph.D. (biology) from Columbia University. He currently has professorial appointments in the Department of Earth and Environmental Sciences (Center for Environmental Research and Conservation) at Columbia University and in Biology at the City University of New York. His research interests are systematic biology, biological diversification, and biogeography. He has written or edited books on phylogenetics and the biodiversity crisis (2000), in addition to over 150 scientific papers. He is a recipient of the Elliott Coues Award from the American Ornithologists' Union, and was elected a Fellow of the American Association for the Advancement of Science. He is a member of 14 professional societies and has held office or served on the board of many of them, including being a past President of the Society of Systematic Biologists. Over the past decade he has been active in efforts to promote systematics and biodiversity science, including Systematics Agenda 2000/US (co-chair), Systematics Agenda 2000 International (Steering Committee), Biodiversity Panel of the President's Council of Advisors for Science and Technology, OSTP (member), and the international biodiversity science program Diversitas (Steering Committee). He is current organizing (with Michael Donoghue) a Diversitas project for the International Biodiversity Observation Year (IBOY) on the Tree of Life, which will be the subject of a symposium at AMNH in September 2001.

Relevant Publications

Cracraft, J. 1989. Speciation and its ontology: the empirical consequences of alternative species concepts for understanding patterns and processes of differentiation. Pp. 28-59 in Speciation and its consequences . D. Otte and J. Endler, eds. Sinauer Assoc., Sunderland, Ma.

Cracraft, J. 1997. Species concepts in systematics and conservation biology — an ornithological viewpoint. Pp. 325-339 in Species: The Units of Biodiversity. M. F. Claridge, H. A. Dawah, and M. R. Wilson, eds. Chapman and Hall, London.

Cracraft, J., J. Feinstein, J. Vaughn, and K. Helm-Bychowski. 1998. Sorting out tigers (Panthera tigris): mitochondrial sequences, nuclear inserts, systematics, and conservation genetics. Animal Conservation 1: 139-150.

Cracraft, J. 2000. Species concepts in theoretical and applied biology: a systematic debate with consequences. In Species Concepts: A Debate. Q. Wheeler and R. Meier, eds. Columbia University Press, New York.

<<Back to Presenters page