One of the (many) things I find fascinating about science is how often research involves crossing the boundaries between disciplines. Ideas from one realm cross-fertilize with ideas from somewhere else, and the result is often unexpected and eye-opening.
Of course, to be honest, a lot of those boundaries are artificial constructs in the first place. I run into this all the time as a book sorter for our local Friends of the Library used book sale. Is a donated book anthropology? Or sociology? Or gender studies? You can probably think of examples of books that could plausibly go in any of the three. The same is true for a lot of books and scholarly papers. Many of them -- often some of the best ones -- represent a drawing together of ideas from disparate sources, and blending them together to get something fresh and new.
The reason this comes up is because of a study sent to me by a friend and frequent contributor of topics for Skeptophilia, that combines genetics, linguistics, and archaeology. Led by Andrés Moreno-Estrada of the National Laboratory of Genomics for Biodiversity in Guanajuato, Mexico, the team used genomic studies, patterns of languages, stone building techniques, and even such things as the distribution of certain food crops (like sweet potatoes) across the Pacific to reconstruct the movements of the extraordinary explorers who settled those islands centuries ago.
I mean the "extraordinary" part quite literally. What these people did is almost unimaginable. The Pacific is enormous. The islands of Polynesia are widely-spaced specks of land, some only a few square kilometers in area, separated by hundreds or thousands of kilometers of open ocean. In nothing more than hand-built wooden canoes, these people launched out into the sea, somehow using natural phenomena (like patterns of clouds and the movements of seabirds) to find their way from one island to the next. How many of them died trying is unknown and unknowable; but that any succeeded is astonishing. And enough did succeed that one at a time, they settled all the habitable islands between Samoa and Rapa Nui (Easter Island) -- a distance of 6,600 kilometers.
I don't know about you, but I can't even begin to imagine what kind of incentive it would take for me to jump into an open canoe, leave behind home and family, and try to paddle my way to a hoped-for speck of land five hundred kilometers away. I've done a lot of traveling, including to some pretty exotic places, but that'd be a big old nope for me.
The team used not only genetic evidence from current residents of the islands, but archaeological evidence -- especially the habit of the Polynesians of building stone monoliths. The most famous ones are the giant stone heads on Rapa Nui, but the Polynesian culture took this art form wherever they went. Monolithic human statues are found all across the Pacific, and even in the ones on the distant Marquesas Islands, you can see the connection with the iconic moai.
What's coolest is that the pattern of the linguistic evolution and the map of the genetic relatedness between the people on the islands of Polynesia line up pretty much perfectly. Put more simply, more closely-related people speak more closely-related languages, and therefore both the languages and the people who speak them diverged from a more recent common ancestor. The alignment of the genetic and linguistic studies supports the usefulness of both for determining patterns of migration -- and clearly could be applied to studying the history of other cultural groups.
Anyhow, the whole thing is pretty amazing, and a great example of what happens when you have creative hybridization between research in different fields. A fascinating study of the legacy of the fearless seafarers of Polynesia who set off into an uncharted ocean -- and ended up colonizing islands all the way across the Pacific.