Outrigger canoes at shoreline, Honolulu, Hawaii, c. 1922
Photo Credit: US Library of Congress
Cultural evolution is a long-standing theory about how societies change. Briefly, cultural evolution argues that cultures change in reaction to non-cultural forces (see the glossary entry of cultural evolution if you need more details). While that might sound like pretty much a no-brainer, the concept is not used much today, because it's so deucedly hard to break out the causes for any societal change. Sure, adaptation is part of the mix; but so are social changes and biological changes and a whole raft (if you'll pardon the pun) of forces at work.
But, in a paper published in the Proceedings of the National Academy of Sciences Early Edition for 18 February 2008, researchers Deborah S. Rogers and Paul R. Ehrlich report that they have found an example where you can peel out the evolutionary causes: canoes of the Polynesian island colonization.
Polynesian Colonization
Canoe from Manihiki Island, showing pattern of sewn washstrake pieces (necessary when large tree trunks are not available for hull construction). Every island group studied had at least one type of canoe hull made from a single large tree trunk, but most groups also had designs with built-up parts, usually sewn with sennit but some attached with woodwork joining techniques
Photo Credit: Darryl Wheye, Science Art (c) 2007 based on Haddon and Hornell, 1936–1938. Courtesy PNAS/National Academy of Sciences.
First, a little background. The Lapita complex is the archaeologists name for the cultural group who colonized the Polynesian islands between about 1400-900 BC. In turn the new Polynesians colonized several island groups outwards out of Tonga and Samoa beginning about 500 BC, arriving in the Marquesas about AD 300, the Hawaiian islands by 800-900 AD, and finally in New Zealand about 1200 AD. In the 1930s, a study of traditional canoe design by the various Polynesian island groups was conducted by AC Haddon and James Hornell, using ethnographic and historical sources: it is this study that provides the data for examining cultural change.
What Rogers and Ehrlich did was look at characteristics of the different canoes--both functional characteristics (such as outrigger attachments, construction technique, keel shape) and symbolic characteristics (such as painting, detailed design elements, figureheads) of the 'traditional' (pre-European) canoes from each of the island groups described by Haddon and Hornell. They discovered that the functional characteristics changed more slowly than the symbolic ones. In other words, canoe construction techniques persisted, with the Polynesians bringing along traditional techniques but changing decorative features as they colonized arrived in each of the island groups in sequence.
Carved figurehead on Maori war canoe (New Zealand). Marked differences in canoe profiles may have facilitated long-distance identification of parties during warfare.
Photo Credit: Darryl Wheye, Science Art (c) 2007 based on Haddon and Hornell, 1936–1938. Courtesy PNAS/National Academy of Sciences.
Does this show the impact of cultural evolution? Oh, yeah. It's maybe even a no-brainer: canoe construction is something that if it succeeds, you stay with it. But what it also shows is that you can actually measure the effects of cultural evolution. There are some residual problems with the study---for one thing, construction is in part a function of whether you have standing trees on the island or not--but the analysis continues and it will be interesting to see what other things come out of the work.
Sources
Haddon, A.C and James Hornell. 1975. (reprint) Canoes of Oceania, Bishop Museum Press, Honolulu, Hawai'i. Part of this book is reproduced online on the PapuaWeb site.
Kirch, Patrick V.2004 Archaeology of the Polynesian Islands. In International Encyclopedia of the Social & Behavioral Sciences. Neil J. Smelser and Paul B. Baltes, eds. Pp. 10987-10990. London: Elsevier.
Rogers, Deborah S. and Paul R. Ehrlich 2008 Natural selection and cultural rates of change. Proceedings of the National Academy of Sciences Early Edition 18 February 2008:1-5.
Comments
Your version of the cultural evolution model is no longer popular because it just not interesting. Researchers into cultural phenomena are interested in the internal processes and mechanism that lead to transformations in cultures. If the climate changes and forces the collapse of a civilization then that adds very little to our understanding of how cultures function and change. If a culture transforms to a new configuration without any apparent “external” pressures, then that is an interesting aspect of culture that is worth understanding.