Over at The Scientist Neil S. Greenspan has an article up, Darwin and deduction:
One of the most remarkable but insufficiently noted features of Charles Darwin's conception of evolution is that its logical implications are still being worked out. I am not merely claiming that experimental and observation studies continue to make use of and bear on Darwinian ideas and principles. I am calling attention to the fact that after almost a century and a half, new deductions are still being teased out of his very fertile axioms of descent with modification and natural selection.
One of the primary criterion which scientists use to judge the utility of a theory is its inferential power. It is one thing to describe; but another to predict. This is one reason I recommend all my friends to read The Genetical Theory of Natural Selection; R. A. Fisher's attempt to create a mathematical framework in which to conceptualize the action of natural selection within evolutionary process. To a great extent I think Fisher fails in his grandest objectives, but fundamentally I think the exposition clarifies one's thinking fruitfully.