Evaluating multiple criteria for species delimitation: an empirical example using Hawaiian palms (Arecaceae: Pritchardia)

BMC Evolutionary Biology

Research Article

Miles J McKenna¹  Mark P Simmons¹  Christine D Bacon²  Warren L Wagner³ 

[1] Department of Biology, Colorado State University, 80523-1878, Fort Collins, CO, USA;Department of Biology, Colorado State University, 80523-1878, Fort Collins, CO, USA;Smithsonian Tropical Research, Box 0843-03092, Balboa, Ancón, Republic of Panamá;Department of Botany, Smithsonian Institution, MRC-166, P.O. Box 37012, 20013-7012, Washington, D.C., USA;

关键词: Hawaii;    Hybridization;    Lineage sorting;    Microsatellite;    Pritchardia;    Radiation;   

DOI  :  10.1186/1471-2148-12-23

 received in 2011-11-03, accepted in 2012-02-22,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundRobust species delimitations are fundamental for conservation, evolutionary, and systematic studies, but they can be difficult to estimate, particularly in rapid and recent radiations. The consensus that species concepts aim to identify evolutionarily distinct lineages is clear, but the criteria used to distinguish evolutionary lineages differ based on the perceived importance of the various characteristics of evolving populations. We examined three different species-delimitation criteria (monophyly, absence of genetic intermediates, and diagnosability) to determine whether currently recognized species of Hawaiian Pritchardia are distinct lineages.ResultsData from plastid and nuclear genes, microsatellite loci, and morphological characters resulted in various levels of lineage subdivision that were likely caused by differing evolutionary rates between data sources. Additionally, taxonomic entities may be confounded because of the effects of incomplete lineage sorting and/or gene flow. A coalescent species tree was largely congruent with the simultaneous analysis, consistent with the idea that incomplete lineage sorting did not mislead our results. Furthermore, gene flow among populations of sympatric lineages likely explains the admixture and lack of resolution between those groups.ConclusionsDelimiting Hawaiian Pritchardia species remains difficult but the ability to understand the influence of the evolutionary processes of incomplete lineage sorting and hybridization allow for mechanisms driving species diversity to be inferred. These processes likely extend to speciation in other Hawaiian angiosperm groups and the biota in general and must be explicitly accounted for in species delimitation.

【 授权许可】

CC BY   
© Bacon et al; licensee BioMed Central Ltd. 2012