Authors: Kai Müller Dirk C Albach
Publish Date: 2009/12/19
Volume: 70, Issue: 1, Pages: 44-56
Abstract
The evolutionary rate at which DNA sequences evolve is known to differ between different groups of organisms However the reasons for these different rates are seldom known Among plants the generationtime hypothesis which states that organisms that reproduce faster also have more DNA substitutions per time has gained most popularity We evaluate the generationtime hypothesis using 131 DNA sequences from the plastid trnLF region and the nuclear ribosomal ITS region of the genus Veronica Plantaginaceae We also examine the alternative hypothesis that a higher substitution rate is correlated with selfing breeding system Selfing is associated with annual life history in many organisms and may thus often be the underlying reason for observed correlations of annual life history with other characters We provide evidence that annual life history is more likely to be the responsible factor for higher substitution rates in Veronica than a selfing breeding system Nevertheless the way in which annual life history may influence substitution rate in detail remains unknown and some possibilities are discussedThis research was funded by the Fonds zur Förderung wissenschaftlicher Forschung FWF Austria project P15336 KM thanks the Deutsche Telekom Stiftung for financial support 3 years ago when initial ideas and analyses for this study emerged Some of the tests herein have been designed in the context of research funded by DFG Grant MU 2875/21 to KM We thank Mark Chase for comments on an earlier version of the manuscript and two anonymous reviewers for helpful remarks
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