David Sloane Wilson, a controversial and fascinating figure, has a series of posts up on Economics and Evolution.  I commented quite comprehensively on the first post in support, and I'll reproduce it here for the sake of interest.

Here are the links to the three posts that are currently up:

• Economics and Evolution as different paradigms I
  
• Economics and Evolution as different paradigms II: The Allais Paradox
  
• Economics and Evolution as different paradigms III: The Case of Norms
  

And my comment:
First, thanks for this post - trying to turn (or to help Economics evolve into) an evolutionary science is something that inspires me and more power to you.

Second, yes Hayek did use evolution as a metaphor and brought an evolutionary epistemology into The Fatal Conceit, but he didn't help to formalize the problems that many economists hope to deal with, e.g. out of equilibrium dynamics, that can be dealt with using more formal evolutionary ideas, say the replicator dynamics. For this see Sam Bowles's text Microeconomics: Behavior, Institutions and Evolution where he gives a big nod to the work of Hayek.

Third, and moreover, when one commenter says, "I think there's another "evolutionary economics" that deals with innovation and here evolution is more of a metaphor, but in my personal opinion a metaphor that has been abused." They need to look at the work of Herb Gintis, Samuel Bowles, Rob Boyd, Peter Richerson, and so many others because they do not misuse the metaphor, but do their best to formalize their thinking rigorously (rigor here not necessarily requiring math, but requiring an understanding of selection pressures).

Fourth, on economics as bastard child of physics, as DSW says it does not harm his general point if currently economics does not resemble current physics, the point revolves around what occurred in the history of economic thought around the late 19th and early 20th centuries. Pareto, Marshall, Walras and others were trying to solve a problem, that is searching for a way to achieve and understand economic equilibrium, the tools of which appeared in contemporary physics and the introducion of 'marginalism'. But, to get equilibrium Walras required such things as 'tatonnement' and what later became known (with Koopmans, Arrow, Debreu and other's beautiful depictions) as the Walrasian Auctioneer - one of many farcical assumptions. The tools for out of equilibrium dynamics, punctuated equilibrium and other phenomena that we observe in evolutionary theory just weren't there. And, as many economists and evolutionists can tell you, once you lock in to a specific equilibrium it can take a lot (e.g. a change of environment) before mutations allow the movement towards a different equilibrium. As DSW argues, we can look to evolutionary theory both to improve our understanding of economics as science, and to understand what will occur within economics in response to 'evolutionary economics' (say, dynamics of inter-group competition as in group selection models that have been used for modeling cultural evolution).