importance of deleterious mutations in adaptive evolution</font>
<font size="2"> Posted on 08/
One might think that deleterious mutations will always be disadvantageous in adaptive evolution. [http:// dx. doi.org/ 10. 1073/pnas. 1313424110 Yet in a study published in PNAS this week,] UT Research Educator and Wilke-lab member [http:// artcovert.is-a-teacher.com/ Art Covert] shows that populations experiencing deleterious mutations can often do better, in the long run, than comparable populations in which deleterious mutations have been disabled. This seemingly paradoxical result arises because deleterious mutations can serve as stepping stones in adaptive evolution: sometimes, higher fitness peaks are inaccessible to populations unless the populations first take a step down into a fitness valley. This paper was co-authored with Richard Lenski (MSU), Claus Wilke (UT Austin), and Charles Ofria (MSU).