Brian Thomas’ article for Wednesday – Moles Can Smell in Stereo – is a quickie. The subject is well summarised by that title: new research does indeed show that eastern moles specifically do smell in stereo, in much the same way as an animal might hear or see in stereo. This research was discussed in much more detail at Carl Zimmer’s blog The Loom, so there is no need to go over it here.
Were does creationism come in? Thomas says:
Stereo smell can only work if the nervous system can detect a difference in the strength of an odor entering each nostril. Considering the tiny distance between the nostrils, the precision and miniaturization of this biological chemical detector is mind-boggling.
There’s no reason why this could not have been achieved by evolution (certainly not one that’s explained in this article), yet he seems to think there is. It may also be worth noting something from Zimmer’s post at this point. This is that the moles are probably only using this system when the difference between odour intensity in each nostril is fairly significant:
Catania [the author of the paper (open access)] concludes that moles probably use both stereo and hot-cold strategies to find food. From a distance, hot-cold works well. Closer up, where smells can get much stronger over even a short distance, the moles switch to stereo.
The system is thus likely to be much less impressive than Thomas makes out. It also perhaps provides a way for evolution to produce whatever is behind it: Like as not, any animal can probably smell in stereo if the source is close enough (except humans, I expect, as we are pretty bad at smelling in general). Successive small improvements could then increase the distance that stereo can be used, until we get to the feats that eastern moles are capable of producing.
All that aside, Thomas concludes:
Whether noticed or ignored, one can always detect the scent of the expert Designer behind any expert design. And these blind moles certainly emanate the fragrance of design.
The family of scatological jokes that could go here are so obvious I don’t even need to spell them out.