Track topics on Twitter Track topics that are important to you
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
Gigantism-very large body size-is an ecologically important trait associated with competitive superiority. Although it has been studied in particular cases, the general conditions for the evolution an...
Sea turtles face threats globally and are protected by national and international laws. Allometry and scaling models greatly aid sea turtle conservation and research, and help to better understand the...
Body size variation has played a central role in biogeographical research, however, most studies have aimed to describe trends rather than search for underlying mechanisms. In order to provide a more ...
Sexual size dimorphism (SSD) arises when the net effects of natural and sexual selection on body size differ between the sexes. Quantitative SSD variation between taxa is common, but directional intra...
The taxonomy of giant Galapagos tortoises (Chelonoidis spp.) is currently based primarily on morphological characters and island of origin. Over the last decade, compelling genetic evidence has accumu...
The aim of this study is to analyze the variation of adiponectinemia and its molecular forms in RA patients receiving tocilizumab therapy.
The purpose of this study is to find out if folic acid prevents of the reduction of fetal body and brain size in infants whose mothers smoke.
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...
Myelodysplastic syndromes (MDS) is a group of heterogeneous diseases characterised by the clonal evolution of dysplastic hematopoietic stem cells. This evolution is associated with accumul...
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.