The Holostei: a case of agreement between molecular phylogeny and palaeontology, to which the latter contributes the history that molecules cannot tell.

LÓPEZ-ARBARELLO, A. & SFERCO, M.E.

Berlin, Alemania

Conferencia; International Conference "Celebrating Darwin: From The Origin of Species to Deep Metazoan Phylogeny"; 2009

Museun fuer Naturkunde

The “Halecostomi vs. Holostei”(“gar-Amia-teleost” problem) is currently a hot topic in actinopterygian systematics because recent molecular and morphological phylogenetic analyses propose the monophyly of Holostei, which has been considered a grade group. We propose that the “Halecostome paradigm” has been misled by the erroneous interpretation of the evolution of certain morphological characters. Only after detailed morphological studies of basal actinopterygians, almost exclusively extinct taxa, and the thorough analysis of their phylogenetic relationships, the evolutionary history of those characters is becoming clear, resulting in the renaissance of the Holostei Hypothesis. There is certainly no intrinsic problem in the morphological data, but in our possible misinterpretation of them. In this respect, evidence from the fossil record is essential. The science of palaeontology contributes not only in establishing the phylogenetic relationships of extinct taxa, but also through palaeobiogeographic, palaeoenvironmental, and palaeoecological studies towards the reconstruction of the evolutionary scenarios that led to the origin of our modern biodiversity. The present contribution is aimed to emphasize the importance of incorporating fossils in morphological phylogenetic studies and the fact that palaeontology is one of the most important sources of information to reconstruct the evolutionary processes that led to the distribution, diversity and ecology of the Recent organisms.