A Loverly Bunch of Coconuts

Some things about coconuts blow my mind.

There are about a million interesting things to say about coconuts (Cocos nucifera). For example, what can’t you use them for? Oil, fiber, food, beverages of the virgin and non-virgin varieties, fuel for fire, structural use, livestock feed, etc. times one million. But for now, let’s focus on two things which still seriously impress me.

1)      Ever had coconut water? That’s the delicious and nutritious liquid inside a green coconut when you cut it open – it is sweet and clear or slightly cloudy. Coconut milk is a bit different; the milk is produced by pressing liquid out of the mature coconut meat (technically endosperm), resulting in a white, creamy, oil-rich milk.  The younger a coconut is, the more water (and less meat) a coconut contains. The health benefits of coconut water are widely, and perhaps undeservedly, touted by marketers of sports and energy drinks.  But what is it? Why is there a bunch of liquid floating around on the inside of a nut? This is the crazy part. Young coconuts are coenocytic – that is, coconut water is composed of free nuclei and cytoplasm, BUT NO ACTUAL CELLS. Nuclei soup! No cell membranes, no cell walls, just a juicy soup of cell contents. As the coconut matures, nuclei settle against the hard shell (technically endocarp) and build cell walls around themselves, solidifying into oil-rich coconut meat.

Pan-global coconut distribution

2)      NATIVE TO NOWHERE. Ok, that’s an exaggeration. But coconut gets around. Coconuts can remain viable at sea for up to 110 days or 3000 miles (some of the experiment showing this performed by Charles Darwin himself!). So for a long time, scientists could not pin down the origin of the coconut. They seemed to thrive everywhere with ocean and warm temperatures, whether that particular piece of beach was known to man or not. Their range circles the globe. C. nucifera is the only species in the genus. But fossilized C. zeylandica specimens have been found in New Zealand and India, dating back to the late Tertiary, at least two million years ago (Harries, 1992). Speculation, and the presence of many cultivars and coconut pests, put the domestication origin of coconut in the Southeast Asian islands of Melanesia. Then last year, a study using microsatellite* markers proposed two separate origins of domestication, resulting in distinct and highly genetically differentiated subpopulations. These subpopulations mapped to the islands of Southeast Asia and the southern coast of the Indian subcontinent. Hybrids between the two occur along ancient Austronesian trade routes. Once domesticated, the coconut was most likely carried to the rest of the equatorial globe by sea-faring peoples, becoming pan-global about 500 years ago.

Coconut palms along a river, in Kerala, India.

Bravo, Master Coconut!

*Microsatellites (also knows as SSRs, or “microsats” on the streets) are sequences of 2 – 6 DNA bases, which are repeated over and over again. The number of times a particular sequence is repeated is heritable, and can be used to trace the ancestry of an individual.

 

Harries, H.C. (1992) The biogeography of the coconut palm. Principes 36, 155­62

Gunn, B., Baudouin, L., & Olsen, K. (2011). Independent Origins of Cultivated Coconut (Cocos nucifera L.) in the Old World Tropics PLoS ONE, 6 (6) DOI: 10.1371/journal.pone.0021143