Evolution Yoga is evolving. The popular yoga studio, which has occupied a brick building on Kilburn Street in Burlington's South End for the past nine years, is splitting into two separate entities: Evolution Yoga will continue to offer adult yoga classes and physical therapy; Evolution Prenatal + Family Yoga Center will focus exclusively on pre- and postnatal classes, plus baby and kids yoga. Susan Cline Lucey, a cofounder of Evolution Yoga, will head up the new venture. The two businesses will share studio space, but there will be some physical changes to the building. Starting in June, one of the smaller yoga studios will be transformed into a lobby exclusively for families, so that breastfeeding moms and kids can linger after class. New class offerings will include family yoga classes, a postpartum support group and a playgroup run by the local chapter of Babywearing International. For her part, Cline Lucey, a certified doula and childbirth educator, is thrilled to be able to focus on the work she's passionate about. "It's an opportunity to be more of a hub for pregnancy wellness and education," she said.