Lenski agrees that the beneficial mutations seen in his Long Term Evolution Experiment are overwhelmingly degradative or loss-of-function ones.
Perhaps the evidence for the vast scope of Darwin’s theory really isn’t as strong as biologists over the years have been telling each other.
Their review pretty much completely misses the mark. Nonetheless, it is a good illustration of how sincere-yet-perplexed professional evolutionary biologists view the data.
Professor Lenski’s contrasting of the frequency versus importance of evolutionary changes is misconceived and his illustrations are inapt.
Richard Lenski has spent decades overseeing the most extensive, most acclaimed laboratory evolution experiment conducted to date.