Tastes great, less filling

A few months back, Nature published a series of papers on the completion of the chimpanzee genome, including a massive comparison of the human and chimp genomes (free online). One of the major utilities of having two closely-related genomes to compare (in addition to showing that humans and chimps have close common ancestors, as in Ken Miller’s testimony on Day 1 of the Kitzmiller v. Dover trial) is that genes that are evolving rapidly under natural selection can be detected.

At the time, an odd observation stuck in my head: not only were things like immune system genes evolving rapidly (as they do in apparently all mammals studied thus far – it’s a war zone out there with the microbes), but according to Table 4 of the Nature article, so were some olfactory and taste receptor genes. This seemed rather odd, given that humans are not exactly first among the beasts when it comes to sniffing capabilities, or, I presume, tasting (although according to this PNAS article, our “gustatory receptors” are doing rather better than our olfactory receptors, many of which have become pseudogenes).

Even with our modest capabilities in this area, however, there are evidently some pretty important things that at least our taste receptors can do. Protect humans from malaria, for example. Read Carl Zimmer’s latest to find out how.

Note: (I take a personal interest in this, because while in Zambia at the age of 7, I caught chloroquine-resistant malaria, even though I took my nasty, bitter chloroquine tablets every week. I was quite ill for a month (I was not diagnosed until I was back in the U.S. for some time, where malaria is not exactly the first diagnosis that comes to the mind of the typical doctor). So it was never quite “Evolution Schmevolution” for me.)

Another note: Today’s GROAN Award (GROAN = Gratuitous, Ridiculous, and Onerous Acronyms by Nerds) goes to HORDE, the Human Olfactory Receptor Data Exploratorium.

Yet one last note: If you’re wondering what that red thing is up at the front of the post, read about the episode of the cartoon The Tick entitled “The Tick vs. Science”, and focus on the mad scientist Dr. Mung Mung and his creation, Tongue Tongue.