"Iconoclastic Artist Expands Definitions of Drawing," trumpets the press release for Richard Tuttle's new installation, titled "It's a Room for 3 People." Well, it's a bit late for that. Tuttle has long been known as the most tentative of post-minimalists. After he burst on the scene decades ago with a stunningly casual installation at the Whitney, his perfect little nothingsa bit of cardboard, some barely there scraps of wood or cloth, maybe a dab of painthave been the most self-effacing pieces in many a show. Now he goes all out in a rhythmic interplay of small works on paper punctuated by sporadic sculptures and culminating on (yes, on) a patterned wall painting. This lighthearted procession underlines how perfectly calibrated his touch is, as well as how decorative such throwaway gestures can now seem. But the real revelation is this work's shy sociability. Divided into five parts (which Tuttle calls "Villages"), the clusters trace the random genealogy of a red mark, a gray chunk, or some other family resemblance of color or material. The sculpturesa warped glittery slab, a sky-blue enamel grid, a fanciful construction with chicken wirefunction as territorial marker posts. If they also allude to Serra or LeWitt, it's as village elders in an informal society of forms on the verge of evolutionary extinctionand genetic rebirth.