Archaeological ruins and historical documents are not the only means of learning about human history. In fact, biological evidence—specifically DNA—can play a crucial role in uncovering previously unknown pieces of our past. Interestingly, we do not necessarily have to look at human DNA. In a recent study, the DNA of coconuts has proven extremely useful in understanding human trade routes, migration patterns, and agricultural practices.

The popularity of coconuts can be attributed to the wide variety of benefits humans have discovered in them—nourishment, hydration, oil, fuel for fire, and fiber for ropes. Given their ubiquity and given human propensity to travel with coconuts, Kenneth Olsen at Washington University initially believed that many coconuts among various places would be indistinguishable due to homogenization.

However, quite the opposite is true. By studying the DNA of over 1300 coconuts around the globe, Olsen and a team of researchers from the United States, Australia, and France, made a number of discoveries about our past. For example, by comparing the distinct genetic profiles of coconuts from areas in the Pacific and the Indian Oceans, they concluded that coconuts had been cultivated separately in those two regions.

By examining the geographical pathways that correspond to the genetic assimilation of the two types of coconuts, the researchers identified ancient trade routes and human migration patterns, outside of which the genes did not mix. Such routes of mixed coconuts were identified in Madagascar.

Many coconuts were carried far from their original destinations. The researchers noted that coconuts in Florida were originally brought to the New World from the Indian Ocean. Indian coconuts were also found on the West Coast of Africa, in the Caribbean, and in Brazil. Coconuts in Mexico were transported by the Spanish from the Pacific.

Discussion Question: What other plants would potentially be good resources for shedding light on human history?

News Article: http://www.sciencedaily.com/releases/2011/06/110624142037.htm
Journal Article: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0021143

Image Source: http://www.publicdomainpictures.net/view-image.php?image=14659&picture=coconut-2&large=1