The evolution of island gigantism and body size variation in tortoises and turtles.
Biol Lett
; 7(4): 558-61, 2011 Aug 23.
Article
em En
| MEDLINE
| ID: mdl-21270022
ABSTRACT
Extant chelonians (turtles and tortoises) span almost four orders of magnitude of body size, including the startling examples of gigantism seen in the tortoises of the Galapagos and Seychelles islands. However, the evolutionary determinants of size diversity in chelonians are poorly understood. We present a comparative analysis of body size evolution in turtles and tortoises within a phylogenetic framework. Our results reveal a pronounced relationship between habitat and optimal body size in chelonians. We found strong evidence for separate, larger optimal body sizes for sea turtles and island tortoises, the latter showing support for the rule of island gigantism in non-mammalian amniotes. Optimal sizes for freshwater and mainland terrestrial turtles are similar and smaller, although the range of body size variation in these forms is qualitatively greater. The greater number of potential niches in freshwater and terrestrial environments may mean that body size relationships are more complicated in these habitats.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tartarugas
/
Ecossistema
/
Tamanho Corporal
/
Evolução Biológica
Limite:
Animals
País/Região como assunto:
Africa
/
America do sul
/
Ecuador
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article