Peter A. Larsen1, María R. Marchán-Rivadeneira, and Robert J. Baker
-Author Affiliations
Department of Biological Sciences and Museum, Texas Tech University, Lubbock, TX 79409
Edited* by David M. Hillis, The University of Texas, Austin, TX, and approved May 11, 2010 (received for review January 5, 2010)
Abstract
Most diploid species arise from single-species ancestors. Hybrid origins of new species are uncommon (except among polyploids) and are documented infrequently in animals. Examples of natural hybridization leading to speciation in mammals are exceedingly rare. Here, we show a Caribbean species of bat (Artibeus schwartzi) has a nuclear genome derived from two nonsister but congeneric species (A. jamaicensis and A. planirostris) and a mitochondrial genome that is from a third extinct or uncharacterized congener. Artibeus schwartzi is self-sustaining, morphologically distinct, and exists in near geographic isolation of its known parent species. Island effects (i.e., area, reduced habitat variability, and geographic isolation) likely have restricted gene flow from parental species into the Caribbean populations of this hybrid lineage, thus contributing to local adaptation and isolation of this newly produced taxon. We hypothesize differential rates of the development of reproductive isolation within the genus and estimate that 2.5 million years was an insufficient amount of time for the development of postzygotic isolation among the three species that hybridized to produce A. schwartzi. Reticulated evolution thus has resulted in a genomic combination from three evolutionary lineages and a transgressive phenotype that is distinct from all other known species of Artibeus. The data herein further demonstrate the phenomenon of speciation by hybridization in mammals is possible in nature.
Artibeus Chiroptera hybrid speciation reticulate evolution transgressive segregation
Footnotes
1To whom correspondence should be addressed. E-mail:peter.larsen@ttu.edu.
Author contributions: P.A.L., M.R.M.-R., and R.J.B. designed research; P.A.L. and M.R.M.-R. performed research; P.A.L., M.R.M.-R., and R.J.B. analyzed data; and P.A.L., M.R.M.-R., and R.J.B. wrote the paper.
The authors declare no conflict of interest.
↵*This Direct Submission article had a prearranged editor.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. GQ861586–GQ861814 and GU356393).
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1000133107/-/DCSupplemental.
Freely available online through the PNAS open access option.
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