Abstract
BackgroundThe metabolic theory of ecology stipulates that molecular evolutionary rates should correlate with temperature and latitude in ectothermic organisms. Previous studies have shown that most groups of vertebrates, such as amphibians, turtles and even endothermic mammals, have higher molecular evolutionary rates in regions where temperature is high. However, the association between molecular evolutionary rates and temperature or latitude has never been tested in Squamata.ResultsWe used a large dataset including the spatial distributions and environmental variables for 1,651 species of Squamata and compared the contrast of the rates of molecular evolution with the contrast of temperature and latitude between sister species. Using major axis regressions and a new algorithm to choose independent sister species pairs, we found that temperature and absolute latitude were not associated with molecular evolutionary rates.ConclusionsThis absence of association in such a diverse ectothermic group questions the mechanisms explaining current pattern of species diversity in Squamata and challenges the presupposed universality of the metabolic theory of ecology.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0666-4) contains supplementary material, which is available to authorized users.
Highlights
The metabolic theory of ecology stipulates that molecular evolutionary rates should correlate with temperature and latitude in ectothermic organisms
Temperature is a key ecological factor that is commonly used to describe the spatial distribution of species, but it is supposed to have a profound influence on the metabolic rate, and the mutation rate, of ectothermic species [1, 5]
According to the predictions of the metabolic theory of ecology there should be a positive relationship between molecular evolutionary rate and temperature in ectothermic species, because their body temperature depends on external temperature [6]
Summary
The metabolic theory of ecology stipulates that molecular evolutionary rates should correlate with temperature and latitude in ectothermic organisms. Temperature is a key ecological factor that is commonly used to describe the spatial distribution of species, but it is supposed to have a profound influence on the metabolic rate, and the mutation rate, of ectothermic species [1, 5] This has lead to the formulation of the “metabolic theory of ecology” [5,6,7] that predicts accelerated rates of molecular evolution (substitution rates), increased genetic divergence between populations, faster speciation rates and higher species richness when temperature is higher [8]. Higher metabolic rate should increase the rate of cell division leading to the fixation of mutations during the DNA replication process and should produce more oxygen freeradicals that directly damage DNA [10, 11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
