Inadiquacies in the Naturalistic Evolutionary Model

I'm intimidated by that title, but it's the best I could come up with in six words.

I just got out of the most enjoyable Biomedical Engineering seminar in my life (I've only attended a dozen or two, but still . . .). It was interesting, well presented, and I actually had enough background to understand what he was saying. That's certainly preferable to sitting for an hour on Mondays completely confused and feeling inadequate. Perhaps I am actually learning something.

Well, the seminar was by David Walt (Tufts Chemistry Professor) on Optical Fiber Microarrays. Now I'm not going to pretend to understand what he said well enough to explain it to you (and I'm not going to pretend that you'd be interested if I could), but one comment he made in the Q&A section made me think.*

Someone asked if his setup (which can be used as a "nose") gives us any information about how biological noses actually work--how many specific types of sensors we have. He said that it's interesting because theoretically and experimentally it only takes about 100 distinct sensors to detect every (practically) possible combination of odors; however, humans (and dogs for that matter) have around 1000 distinct sensors. He didn't seem to think there's any practical reason why we should have evolved such a unnecessarily precise array of sensors. I was thinking, "Wow, God's such an overachiever. He's amazing." It made me smile.

* On the off chance you are actually interested: Here's his site which I'm sure has more information than you'd ever care about.