Flying rocks and flying clocks: disparity in fossil and molecular dates for birds.
Proc Biol Sci
; 281(1788): 20140677, 2014 Aug 07.
Article
em En
| MEDLINE
| ID: mdl-24943376
ABSTRACT
Major disparities are recognized between molecular divergence dates and fossil ages for critical nodes in the Tree of Life, but broad patterns and underlying drivers remain elusive. We harvested 458 molecular age estimates for the stem and crown divergences of 67 avian clades to explore empirical patterns between these alternate sources of temporal information. These divergence estimates were, on average, over twice the age of the oldest fossil in these clades. Mitochondrial studies yielded older ages than nuclear studies for the vast majority of clades. Unexpectedly, disparity between molecular estimates and the fossil record was higher for divergences within major clades (crown divergences) than divergences between major clades (stem divergences). Comparisons of dates from studies classed by analytical methods revealed few significant differences. Because true divergence ages can never be known with certainty, our study does not answer the question of whether fossil gaps or molecular dating error account for a greater proportion of observed disparity. However, empirical patterns observed here suggest systemic overestimates for shallow nodes in existing molecular divergence dates for birds. We discuss underlying biases that may drive these patterns.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Aves
/
Evolução Biológica
/
Fósseis
Limite:
Animals
Idioma:
En
Revista:
Proc Biol Sci
Assunto da revista:
BIOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Estados Unidos