This book rejects the notion that California's islands were marginal habitats for precolumbian indigenous peoples. Most of the information used for this purpose comes from the Santa Barbara Channel Islands and Isla Cedros along the Baja California coast. Chapter 1 (Erlandson, Gill, and Fauvelle) provides a general review of island biogeography and a historic account of how previous researchers often viewed the islands as marginal places because they assumed island habitats had a paucity of terrestrial foods.
Brajie, Erlandson, Gill, Rick, Bentz, and Collins (Chapter 2) deal with the historical degradation and recovery of California's island ecosystems, focusing on how domestic herbivores denuded native vegetation, creating a false impression that island terrestrial habitats offered limited economic value. But once these species were removed from the islands, a rebound in key subsistence resources occurred—especially geophytes—providing a more realistic picture of these habitats and their value to local people.
In Chapter 3, Gusick and Erlandson challenge the marginality hypothesis by showing that the Northern Channel Islands were occupied at least as early as mainland areas nearby (preceding 12,000 cal BP). Chapter 4 continues the theme of geophyte productivity, as Gill, Erlandson, Niessen, Hoppa, and Merrick describe amazing fields of blue dicks, a perennial herb, that appeared after grazing pressures were released, and they show how plant macrofossil assemblages dating throughout the Holocene are dominated by this carbohydrate-rich food.
In Chapter 5, Anis, Erlandson, Gill, Graham, and Vellanoweth argue for the dietary importance of seaweeds, but they note that inherent taphonomic issues associated with them limit visibility in the archaeological record. They do, however, offer some potential solutions to this problem involving phytoliths, starches, isotopes, and diatoms. Chapter 6 (Erlandson, Gill, Perry, Vellanoweth, and Yatsko) documents the distribution of mineral sources for the production of tools and other commodities across the islands, concluding that their differential abundances were not limiting factors for habitation.
In Chapter 7, Fauvelle and Perry focus on the exchange of multiple commodities. They note that because of the presumed lack of important plant foods on the islands, past researchers have often hypothesized that shell beads produced there were traded to the mainland for resources such as acorns, making it possible to maintain permanent island populations. Thanks to the collection of the plant macrofossil assemblages outlined above, the abundant presence of blue dicks and the near absence of acorn have debunked this marginality hypothesis and challenge ideas about the perceived need for extra-local resources. This conclusion, of course, brings up the question of why so many beads were sent to the mainland. The authors suggest that the beads were associated with maintaining ritual cycles and social ties across the channel.
In Chapter 8, Glassow and Johnson evaluate Late Period (post-1000 cal BP) population densities using a variety of indicators, and they find that Channel Island densities were lower than on the mainland. They also analyze radiocarbon frequencies over time and find Channel Island populations experienced more fluctuations, leading them to conclude that although robust populations existed in many island settings, terrestrial resources were slightly less productive and more sensitive to climatic change than was the case on the mainland.
Rick, Hofman, and Reeder-Myers (Chapter 9) investigate which animals were purposefully introduced to the islands during precolumbian times, and they conclude that they were limited to foxes and dogs. Because some obvious subsistence-related animals like rabbits and deer were not introduced, they suggest that this strategy was not necessary or cost effective because there were enough sources of protein from marine habitats in most island settings.
In Chapter 10, Fitzpatrick and Erlandson conclude with a summary of major findings in the book followed by a discussion of their implications through comparisons with examples from across the globe. The authors encourage readers to reconsider past assumptions about island productivity and antiquity of occupation, and they emphasize how islands can help us better understand human colonization, cultural and demographic change, and human influences on local ecosystems.
This book is an interesting read, achieving its goal of showing that islands are not necessarily marginal places to live. It also makes clear that we should not be fooled by the condition of current environments, as they can be severely altered by postcontact activities. Furthermore, the latter point can be verified through analyses of plant macrofossils and, in the case of the Channel Islands, should reorganize prevailing views of local subsistence systems and interregional exchange. The book is not designed to address these issues with detailed presentation of quantitative data, as only the Glassow and Johnson chapter on human demography uses this strategy. That said, all the chapters are well referenced, allowing motivated readers to find data-rich sources should they want to further evaluate any of the more thought-provoking ideas provided in the volume.
