REFERENCE OF THE DAY: Ronald G. Ledoux and Alan J. Kenyon "Protides of the Mustelidae-II. Immunologic Relatedness." 1974 *Comparative Biochemistry and Physiology* 51A:213-217. This is an oldie but a goodie for several reasons. First of all, the study looks at blood proteins from 14 different mustelids and 2 viveridids, and compared how related the different species are, based on immunologic reactions. This is based on the presumption that the closer related the two species, the less reactions will take place. Second, it shows how correct data can be misinterpreted. And last, it took place in the early 70s when music was still very cool. (I once told a new graduate student that the Beatles had broken up on her birthdate, so I couldn't be her friend. Too much bad karma korn.) In short, the study confirmed that the viverrids are only distantly related to the mustelids, and the subgroups within the Mustelidae are fairly accurate; that is, the skunks group together, as do the badgers, the otters, and the weasels. However, the study (although not discussed, you have to really look at the data) also shows the problems with this type of investigation. According to the results, mink and ferrets (polecats were not tested) are as closely related as are ferrets and sea otters, which we know is not true. This study attempts to use this type of data to form a timeline of evolution; the more reaction, the longer the time of separation. The problem is, just because time passes, things don't to have to change at the same rates. So one group can have more biochemical changes in a shorter time than another group. (The fatal flaw in this paper) Excluding the flaw, the rest of the paper stands up well. Oh yeah, this type of technique (as described in the paper) is not as commonly used because of the advances in genetics (Go Pat!) One bit of irony in the paper. How did they check the relatedness of ferrets to other species? By using antisera made in, you guessed it, rabbits. (Using rabbits to ferret out mustelid relationships? he he he) Mo' Bob and the 18 Nonrelated Rascals (Missing Gus) [Posted in FML issue 1742]