Molecules and fossils reveal punctuated diversification in Caribbean “faviid” corals

• Main Authors: Schwartz Sonja A, Budd Ann F, Carlon David B
• Format: Article
• Language: English
• Published: BMC 2012-07-01
• Series: BMC Evolutionary Biology
• Subjects: Scleractinia; Speciation; Adaptive radiation; Miocene; Pliocene; Coral reef
• Online Access: http://www.biomedcentral.com/1471-2148/12/123

<p>Abstract</p> <p>Background</p> <p>Even with well-known sampling biases, the fossil record is key to understanding macro-evolutionary patterns. During the Miocene to Pleistocene in the Caribbean Sea, the fossil record of scleractinian corals shows a remarkable period of rapid diversification followed by massive extinction. Here we combine a time-calibrated molecular phylogeny based on three nuclear introns with an updated fossil stratigraphy to examine patterns of radiation and extinction in Caribbean corals within the traditional family Faviidae.</p> <p>Results</p> <p>Concatenated phylogenetic analysis showed most species of Caribbean faviids were monophyletic, with the exception of two <it>Manicina</it> species. The time-calibrated tree revealed the stem group originated around the closure of the Tethys Sea (17.0 Ma), while the genus <it>Manicina</it> diversified during the Late Miocene (8.20 Ma), when increased sedimentation and productivity may have favored free-living, heterotrophic species. Reef and shallow water specialists, represented by <it>Diploria</it> and <it>Favia</it>, originate at the beginning of the Pliocene (5 – 6 Ma) as the Isthmus of Panama shoaled and regional productivity declined.</p> <p>Conclusions</p> <p>Later origination of the stem group than predicted from the fossil record corroborates the hypothesis of morphological convergence in <it>Diploria</it> and <it>Favia</it> genera. Our data support the rapid evolution of morphological and life-history traits among faviid corals that can be linked to Mio-Pliocene environmental changes.</p>