The island laboratory concept has long been an important construct in island archaeology, with an emphasis on human biogeography and issues of isolation, connectivity, interaction, evolution, and extinction. The Pacific Coast of Alta and Baja California contains several offshore islands that offer a framework for evaluating a variety of cultural and ecological issues. The California Islands include large islands (>100 km2) with abundant resources that were attractive to ancient people for 13,000 years and numerous small islands (5 km2 in area or less), many of which contain evidence of human occupation for centuries to millennia. Most of these small islands have seen limited archaeological research and often are presumed to have been marginal locations for past human settlement. Today, small islands from San Francisco Bay to Baja California provide key habitat for endemic species, breeding seabirds and marine mammals, and rare plants. Here, we review the archaeology of small islands on California's outer coast, focusing on paleogeography, human settlement dynamics, and ecology and biodiversity. Synthesis of archaeological and environmental data demonstrate the utility of small islands as model systems for evaluating changes in island ecology.
