A strange fact learned via Carl Zimmer, who got it from the journal Genome Biology.

The platypus genome was the subject of much fanfare recenty. (It's amazing how many organisms are getting sequenced lately -- P&G actually funded the sequencing of the organism that causes dandruff.)

It turns out some key genes involved in the digestion are missing, and that this shouldn't be surprising because the platypus apparently lost its stomach somewhere along the evolutionary path that led it away from other mammals. It seems to be alone among vertebrates in this strange feat.