Strong mitochondrial DNA support for a Cretaceous origin of modern avian lineages
Date
2008-01-28
Authors
Brown, Joseph W.
Rest, Joshua S.
Garcia-Moreno, Jaime
Sorenson, Michael D.
Mindell, David P.
Version
OA Version
Citation
Joseph W. Brown, Joshua S. Rest, Jaime Garcia-Moreno, Michael D. Sorenson, David P. Mindell. 2008. "Strong mitochondrial DNA support for a Cretaceous origin of modern avian lineages." BMC BIOLOGY, Volume 6, https://doi.org/10.1186/1741-7007-6-6
Abstract
Determining an absolute timescale for avian evolutionary history has proven contentious. The two sources of information available, paleontological data and inference from extant molecular genetic sequences (colloquially, 'rocks' and 'clocks'), have appeared irreconcilable; the fossil record supports a Cenozoic origin for most modern lineages, whereas molecular genetic estimates suggest that these same lineages originated deep within the Cretaceous and survived the K-Pg (Cretaceous-Paleogene; formerly Cretaceous-Tertiary or K-T) mass-extinction event. These two sources of data therefore appear to support fundamentally different models of avian evolution. The paradox has been speculated to reflect deficiencies in the fossil record, unrecognized biases in the treatment of genetic data or both. Here we attempt to explore uncertainty and limit bias entering into molecular divergence time estimates through: (i) improved taxon (n = 135) and character (n = 4594 bp mtDNA) sampling; (ii) inclusion of multiple cladistically tested internal fossil calibration points (n = 18); (iii) correction for lineage-specific rate heterogeneity using a variety of methods (n = 5); (iv) accommodation of uncertainty in tree topology; and (v) testing for possible effects of episodic evolution.
Description
License
© 2008 Brown et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.