Pretty much everyone agrees that natural selection acting on random genetic mutations can explain some things. The really interesting question is, how much can it explain? Since Darwin’s mechanism seems intuitively plausible, we’re often tempted just to trust our intuitions rather than to look at the hard data. And yet the data increasingly show that, whatever its intuitive attractions, the powers of selection and mutation are surprisingly limited.

In many cases, new biological functions require several mutations. And everyone agrees that natural selection doesn’t have foresight. But it’s widely assumed that if each of the individual mutations leading to new functions are themselves adaptive, then natural selection can traverse the pathway. Again, this makes intuitive sense. But what about the evidence?

In the first research article to be published in the new journal BIO-Complexity, Ann Gauger, Stephanie Ebnet, Pamela Fahey, and Ralph Seelke report on the results of their experiments with one such scenario, using E. coli. The results of the study were not encouraging for the Neo-Darwinian perspective. The paper, “Reductive Evolution Can Prevent Populations from Taking Simple Adaptive Paths to High Fitness,” gives the take-home lesson.

In the current episode of ID the Future, I interview one of the co-authors, Ann Gauger, about this paper and its wider implications. You can listen to the interview here.