Evolutionary clock calibration for rodents
The MURINEVOL (Of mice and rats: a new molecular palaeobiological approach and best practice in divergence time estimation) project focused on the previously unresearched area of Rodentia. Results were significant for calibration of the evolutionary clock as both living or extant and extinct members of the clade were studied. Moreover, the relationships between phenotypic innovations, biogeographic events, climatic changes, and diversification were determined. Fossil taxa were included in molecular clock analysis and MURINEVOL researchers evaluated alternate approaches to characterise morphology. The murine fossil record has been accurately classified via molecular data analysis. Results are impressive and include the analysis of more than 100 extinct and extant taxa, a first in evolutionary research. Application of comparative phylogenetic methods has clarified the role of factors and mechanisms at work during the evolution of some rodent groups. For example, rhizomyine rodent evolution showed connections between monsoon variations such as timing and severity. Synchrotron X-ray fluorescence and absorption spectroscopy as well as infrared spectroscopy were used to image a very well preserved rodent specimen revealing soft tissues and hairs. In addition to a high-resolution 3D reconstruction of the mandible and cranial fragment, researchers were able to reconstruct the whole skeleton. Several papers have been published in peer review journals including ‘A transitional gundi (Rodentia: Ctenodactylidae) from the Miocene of Israel’ in PLoS One. In press, there are four chapters for the ‘Handbook of Mammals of the World’. Integration of multiple sources of new and existing data has produced a state of the art approach to determining divergence time and linking this to phenotypic evolution. Tools and methods developed could be used in the field of evolutionary biology.
Keywords
Evolutionary clock, fossil record, MURINEVOL, molecular data analysis
