The evolution of island gigantism and body size variation in tortoises and turtles.
Summary of "The evolution of island gigantism and body size variation in tortoises and turtles."
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.
Harvard-Westlake School, North Hollywood, CA 91604, USA.
This article was published in the following journal.
Name: Biology letters
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21270022
- DOI: http://dx.doi.org/10.1098/rsbl.2010.1084
Management of species of conservation concern requires knowledge of demographic parameters, such as rates of recruitment, survival, and growth. In the Caribbean, hawksbill turtles (Eretmochelys imbric...
The brain is a trait of central importance for organismal performance and fitness. To date, evolutionary studies of brain size variation have mainly utilized comparative methods applied at the level o...
Twenty-five black river turtles (Rhinoclemmys funerea) and eight white-lipped mud turtles (Kinosternon leucostomum) from Selva Verde, Costa Rica were examined for haemoparasites. Leeches identified as...
Polyploidization and subsequent changes in genome size are fundamental processes in evolution and diversification. Little is currently known about the extent of genome size variation within taxa and t...
The site of Blombos Cave (BBC), Western Cape, South Africa has been a strong contributor to establishing the antiquity of important aspects of modern human behaviour, such as early symbolism and techn...
The purpose of this study is to assess the extent of and sources of variation in the glycaemic index values of foods measured by different laboratories around the world.
The project is designed to test the effectiveness of a multilevel worksite wellness program, based in Rhode Island and nearby neighboring states to impact employee weight, dietary intake a...
Oral epithelial dysplasia (OED) is one of the common precancerous lesions among Chinese adults. Biomarker is not available for detection of malignant potential of OED till now. p16 is an i...
The purpose of this study is to utilize Trinity Evolution as a graft source in tibiotalar arthrodesis and to follow the subjects to measure the clinical outcomes and fusion rate. The hypot...
The current study is part of a large multi-investigator grant to look at the pharmacogenetics of a number of membrane transporters. We will study individuals with particular genotypes of t...
Medical and Biotech [MESH] Definitions
The interdisciplinary science that studies evolutionary biology, including the origin and evolution of the major elements required for life, their processing in the interstellar medium and in protostellar systems. This field also includes the study of chemical evolution and the subsequent interactions between evolving biota and planetary evolution as well as the field of biology that deals with the study of extraterrestrial life.
Evolution at the molecular level of DNA sequences and proteins. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
The physical measurements of a body.
A method of analyzing the variation in utilization of health care in small geographic or demographic areas. It often studies, for example, the usage rates for a given service or procedure in several small areas, documenting the variation among the areas. By comparing high- and low-use areas, the analysis attempts to determine whether there is a pattern to such use and to identify variables that are associated with and contribute to the variation.
A phylum of primitive invertebrate animals that exemplify a simple body organization. Trichoplax adhaerens is considered a key species for early metazoan evolution.