Gene Flow in the Pacific

From the Guardian (hat tip: Paul Halsall), something I’ve always wondered about:

Indigenous Americans had contact with Polynesians 800 years ago, DNA reveals

Indigenous Americans and Polynesians bridged vast expanses of open ocean around the year 1200 and mingled, leaving incontrovertible proof of their encounter in the DNA of present-day populations, new studies have revealed.

Whether peoples from what is today Colombia or Ecuador drifted thousands of kilometres to tiny islands in the middle of the Pacific, or whether seafaring Polynesians sailed upwind to South America and then back again, is still unknown.

But what is certain, according to a study in Nature, is that it took place hundreds of years before Europeans set foot in either region, and left individuals scattered across what became French Polynesia with signature traces of the New World in their DNA.

“These findings change our understanding of one of the most unknown chapters in the history of our species’ great continental expansions,” the senior author Andreas Moreno-Estrada, principal investigator at Mexico’s National Laboratory of Genomics for biodiversity, told AFP.

Read the whole thing.

Inkas

I reviewed Chris Given-Wilson’s contribution to the English Monarchs series, Henry IV, for the Journal of British Studies. I am impressed to learn that he is branching out into… Incan history. From Aeon:

Instead of writing, the Inkas’ principal bureaucratic tool was the khipu. A khipu consists of a number of strings or cords, either cotton or wool, systematically punctuated with knots, hanging from a master cord or length of wood; pendant cords might also have subsidiary cords. The basis of khipuaccounting practice was the decimal system, achieved by tying knots with between one and nine loops to represent single numerals, then adding elaborations to designate 10s, 100s or 1,000s. By varying the length, width, colour and number of the pendant cords, and tying knots of differing size and type to differentiate data, the Inkas turned the khipu into a remarkably versatile device for recording, checking and preserving information.

The main uses to which khipus were put were, firstly, to record births, deaths and movements of people, thereby providing an annual census upon which local labour, military and redistributive assessments could be made. They were also used to count commodities, especially the tribute payable by conquered provinces such as maize, llamas and cloth (there was no coinage). Maize, for example, might be represented by a yellow cord, llamas by a white cord, and so on. Early Spanish chroniclers and administrators were astonished at the accuracy of khipu calculations: according to Pedro de Cieza de León, writing in the late 1540s, they were ‘so exact that not even a pair of sandals was missing’.

Read the whole thing.