In a paper published a couple of weeks ago in Nature, a result of collaboration of  our lab with the lab of Comparative Bioinformatics, we detail the results of a small-lateral but large-vertical scale study of protein evolution. By creating an increadibly large multiple alignment we contrasted the diversity of different amino acids present in orthologous sites with the observed short-term rate of evolution.

Negative selection prevents the fixation of deleterious alleles. Thus, although some deleterious alleles can segregate in the population, conventional wisdom holds that deleterious mutations are evolutionary dead ends. In an letter to Nature published today online we show that for mt-tRNAs this is not always the case.