Temperature‐dependent mutational robustness can explain faster molecular evolution at warm temperatures, affecting speciation rate and global patterns of species diversity

• DOI: 10.1111/ecog.01948
• Publication Date: 2015-11-04T15:46:54Z
• Authors: Mikael Puurtinen; Merja Elo; Matti Jalasvuori; Aapo Kahilainen; Tarmo Ketola; Janne S. Kotiaho; Mikko Mönkkönen; Olli T. Pentikäinen
• Keywords: Robustness; Epistasis; Molecular evolution; Experimental Evolution; Genetic algorithm

Distribution of species across the Earth shows strong latitudinal and altitudinal gradients with number decreasing declining temperatures. While these patterns have been recognized for well over a century, mechanisms generating maintaining them remained elusive. Here, we propose mechanistic explanation temperature‐dependent rates molecular evolution that can influence speciation global biodiversity gradients. Our hypothesis is based on effects temperature temperature‐adaptation stability proteins other catalytic biomolecules. First, due to nature physical forces between biomolecules water, maximal around + 20°C decreases as either or increases. Second, organisms adapted cold temperatures evolved especially flexible (but unstable) facilitate reactions in cold, where movements slow down. Both should result mutations being average more detrimental at (i.e. lower mutational robustness cold). At high temperatures, destabilizing water–biomolecule interactions, need maintain structures withstand heat denaturation, decrease similarly. Decreased extreme will down evolution, larger fraction new be removed by selection. Lower may also select reduced mutation rates, further slowing rate evolution. As requires epistatic incompatibilities prevent gene flow among incipient species, directly which arise. The proposed mechanism thus explain why faster warm contributing higher elevated richness environments characterized stable