Abstract Detail

Systematics Section/ASPT

Barker, Michael [1], Masalia, Rishi [2].

The genomic nature of Linnaean genera.

An implicit assumption of the Linnaean nomenclatural system is that taxonomic ranks—such as family, genus, and species—are equivalent markers of evolutionary divergence and reflect natural discontinuities. Many biologists reasonably believe that Linnaean ranks are arbitrary and do not describe similar scopes of biological diversity, even among related groups of organisms, because of variation in taxonomic practice over time and across organisms. Despite long-standing doubt about the nature of Linnaean taxonomies, they have been widely used by biologists and the broader public for more than 250 years to describe the diversity of life. Here we use genomic data to evaluate the nature of Linnaean genera by comparing the divergence of nuclear orthologs among congeneric plant and animal species representing 74 genera. We find that plant and vertebrate genera circumscribe relatively narrow ranges of diversity with no significant difference (p = 0.089) in ortholog divergence among plant and vertebrate congeners. In contrast, ortholog variation was an order of magnitude higher for invertebrate congeners and significantly different than either plants or vertebrates. Contrary to many biologists' expectations, our results demonstrate that Linnaean genera, and perhaps even higher level ranks such as family, describe similar amounts of variation among related taxa and provide biologically meaningful information about the degree of relatedness of congeneric taxa. These estimates of ortholog divergence may also provide a useful metric for recognizing signatures of hybridization and introgression among plant and vertebrate species. Considering that shared morphological characters classically define Linnaean genera, our results suggest that these traits may be evolving at similar rates in lineages as varied as plants and vertebrates.

Broader Impacts:

Related Links:
http://barkerlab.net

1 - University of Arizona, Ecology & Evolutionary Biology, P.O. Box 210088, Tucson, AZ, 85712, USA
2 - University of Georgia, Department of Plant Biology, 2502 Miller Plant Sciences, Athens, GA, 30602, USA

Keywords:
Genomics
Nomenclature
species concept
genus concept
orthologs.

Presentation Type: Oral Paper:Papers for Sections
Session: 18
Location: Magnolia/Riverside Hilton
Date: Tuesday, July 30th, 2013
Time: 9:30 AM
Number: 18005
Abstract ID:941
Candidate for Awards:George R. Cooley Award