I haven’t, but I can do so. I’ll start a thread.
There are really four major ingredients that went into this stew. I started with the idea of fantasy “races” being adapted to different GURPS terrains, as a basis for their being contemporaneous distinct species. I picked a somewhat familiar Western name for each race, and took some features from the associated folklore; for example, trollwives are smart because there are stories about their cunning and use of magic. I worked out body sizes and proportions systematically, using broad size classes (dwarves at SM -2, ghouls and nixies as SM -1, elves, men, and selkies at SM 0, and trolls at SM +1), different degrees of gracility and robustness, and different degrees of sexual dimorphism (in particular, men had greater sexual dimorphism than in the real world, and were sociologically like pastoral nomads, tending to polygyny—“man the mortal, master of horses”). And then I looked for an animal species or two to stir into each race, not as an exact model but enough for flavor, and to produce interesting behavioral differences. I had a very long, useful discussion of “what do they eat?” on the Steve Jackson Games newsgroups to which Agemegos supplied a lot of really useful suggestions.
And after all that was done, I went back and thought through cladistic paths: trolls and dwarves as the oldest and strangest races, going back perhaps to a glacial era; elves and ghouls as K- and r-selected variants on more gracile races adapted to warmer climates; and men, nixies, and selkies as adapted to environments where mobility was at a premium—men to plains, nixies to rivers (I made them the grain-growing, beer-drinking, trade-focused “men” of the setting, kind of a nod to Tolkien’s hobbits, though they’re more like Sméagol’s kin than the Shirefolk), selkies to islands and beaches. I still haven’t decided which order of branching makes most sense for those three. . . .
It’s a bit different from the game rules you were using, in that I wasn’t building a whole different evolutionary tree back to the Cambrian explosion; I was doing a fantasy world, and fantasy worlds tend to have men in them, so the history has to be similar up till the last million years or so. But the kind of questions that the GURPS Uplift and GURPS Space racial design rules ask went into this; in particular, I went through the racial behavioral categories for all of the races.