Dennis Venema, a Christian Evolutionary Creationist (which means that he is a neo-Darwinist who is also a Christian) made what I consider to be a major concession: that Michel Behe is right about the limits of what neo-Darwinian processes are able to accomplish. Venema, while explaining the latest findings of Lenski's lab, stated:
"If indeed all five (or more) mutations needed for this transition to Cit+ in the LTEE were required simultaneously, we could be confident that the trait would never arise.
Put more simply, Behe is right that numerous mutations occurring simultaneously are too rare to expect in evolution."
This was the essential point that Michael Behe was attempting to make in his book, The Edge of Evolution: that if more than two or three simultaneous mutations for the evolution of a feature were needed, then that feature would never evolve. After all of Venema's efforts at refuting Behe (and he's been at it for quite a while, now), he finally gets around to admitting that Behe is right: There is an edge or limit to what neo-Darwinism can accomplish.
In fairness, Venema goes on to state:
"What he [Behe] has not demonstrated, however, is that evolution must proceed only by numerous mutations occurring simultaneously.”
Perhaps Venema is correct. But it's difficult to know how anyone could ever show that evolution had to occur that way. There might, afterall, be some unknown evolutionary pathway where things proceeded, one selective mutation at a time. But I would suggest that the burden of proof is on neo-Darwinists to show that this is indeed the case and that the whole history of evolution can be explained by this process. To just blindly believe that it can be, without demonstration, requires one of the greatest leaps of faith ever known.
Venema thinks that it at least has been demonstrated in one case:
“ With the LTEE, we have direct evidence of what Behe defines as a “noteworthy gain-of-FCT mutation” occurring step by step, without the need for simultaneous mutations.”
I'll be curious to see if Behe agrees with Venema's assessment.