Hybridization and the Evolution of Reef Coral Diversity
Steven V. Vollmer,*
Stephen R. Palumbi
Hundreds of coral species coexist sympatrically on reefs,
reproducing in mass-spawning events where hybridization appears common.
In the Caribbean, DNA sequence data from all three sympatric Acropora corals show that mass spawning does not erode
species barriers. Species A. cervicornis and A. palmata are distinct at two nuclear loci or share ancestral
alleles. Morphotypes historically given the name Acropora
prolifera are entirely F1 hybrids of these two
species, showing morphologies that depend on which species provides the
egg for hybridization. Although selection limits the evolutionary
potential of hybrids, F1 individuals can reproduce asexually and form long-lived, potentially immortal hybrids with unique
morphologies.
Department of Organismic and Evolutionary Biology, Harvard
University, 16 Divinity Avenue, Cambridge, MA 02138, USA.
*
To whom correspondence should be addressed. E-mail:
svollmer{at}oeb.harvard.edu
