Here's a couple interesting articles I found this evening.
Finches Provide Answer to Another Evolutionary Riddle in Scientific American and
Study Shows How Octopus, Ever the Impersonator, Turns Tentacle into Jointed Limb in Scientific American
Apparently, octopuses assume stiff, jointed tentacle formation when feeding, even though, as invertebrates, they can theoretically bend however they wish. A team of biologists, including Binyamin Hochner at the Hebrew University of Jerusalem, did a study on the cause of the curious tendency, proposing that the stereotypical bend-point position for limbs is favorable from an evolutionary standpoint. The octopus has a near-infinite number of arm positions to deliver food to its mouth, but it sticks with an almost-human conformation. The original journal article can be found here, at The Journal of Neuroscience
The finch story is almost as interesting (cephalopods are one of my favorite topics), but almost purely from the amount of work that went into the study. University of Arizona scientists studied a mating population of 10,000 finches, finding that somehow females chose mates based on significant genetic differences from themselves, not purely from plumage, or in this case, a bright red breast.