Last summer, my wife and I visited Hawaii for the first time. We had been invited over by a friend who teaches at the University of Hawaii at Manoa, and so we flew to Oahu and stayed in Kailua, before hopping to Kauai for a few days of hiking, snorkeling, and general intense relaxation.
I had done some homework ahead of the trip, only to discover upon arrival that there are many things about Hawaii that no amount of preparation in the abstract can make you quite ready for. For me, one of these turned out to be Local food. Reading about poke, laulau, shoyu chicken, musubi, and mochi is entertaining and educational, but let me tell you, the vicarious experience falls far short of the real thing — an actual plate lunch, bowl of saimin, or long rice. Of course, unless you've been to Hawaii, this paragraph will mean very little to you until you land there in person and go have a meal where the locals do.
Given how remote Hawaii is even from the Polynesian islands, let alone from the nearest continental mass to the west, it should not be surprising that it is one of the last places on Earth to have been settled by humans (who started arriving there about 1,700 years ago from Polynesia). On our first day on Oahu, we watched a traditional Polynesian canoe racing off Kailua beach, and looking at the contestants, I kept thinking of their ancestors, on the beach somewhere on Raiatea or Bora Bora, about to launch their voyaging canoe into the blue, without any inkling as to how far they would have to sail until they raise land.
My sense of wonder got a boost that very summer, as I was reading a New Yorker piece by Elizabeth Kolbert titled Sleeping with the Enemy (August 15, 2011, p.64). Kolbert's article was centered around an interview with Svante Pääbo, the director of the Department of Genetics in the Max Planck Institute for Evolutionary Anthropology in Leipzig, and the author of groundbreaking work on the genetics of hominids. As Pääbo noted, neither archaic humans like Homo erectus, nor Neanderthals, ever reached Madagascar or Australia: "It's only fully modern humans who start this thing of venturing out on the ocean where you don't see land. Part of that is technology, of course; you have to have ships to do it. But there is also, I like to think or say, some madness there. You know? How many people must have sailed out and vanished on the Pacific before you found Easter Island? I mean, it's ridiculous. And why do you do that? Is it for the glory? For immortality? For curiosity? And now we go to Mars. We never stop."
Pääbo's mention of Mars struck a chord with me, bringing to mind one of the handful of sci-fi stories that, as I realize in retrospective, have had the strongest influence on my attitude to life and my eventual choice of career. The story, by Arthur Clarke, is Rescue Party, originally published in 1946; I read it as a little boy in the mid-1960s (in a Russian translation). The story tells of an expedition by the representatives of a galactic federation aimed to rescue a species, newly discovered through their radio transmissions, from their planet — Earth — that is about to be obliterated as its star goes nova. I will not divulge here any further details about this wonderful story — you are highly advised to read it for yourself, and if it will not make you proud of being human, I don't know what will.
A full understanding of the genetic, environmental, and cultural underpinnings of what Pääbo calls our "madness" is still a long way off, but exciting discoveries in this area are made all the time. One of the more intriguing discoveries comes from the work of Chuansheng Chen, Michael Burton, Ellen Greenberger, and Julia Dmitrieva, who found a correlation between the population frequency of the so-called long alleles of the DRD4 dopamine receptor and the migration patterns that brought humans out of Africa and scattered them over the globe. Notably, the DRD4 long allele had been linked in previous studies to the personality trait of novelty-seeking and to hyperactivity.
In their paper, published in Evolution and Human Behavior (20:309–324, 1999), Chen et al. reported that migratory populations showed a higher proportion of long alleles for DRD4, compared to sedentary populations. Specifically, the correlation between records of long-distance group migration and the proportion of long alleles of DRD4 was 0.85; the correlation between prevalence of nomadic vs. sedentary lifestyle and the proportion of long alleles was 0.52. Moreover, the geographic distribution of the high prevalence of long alleles correlated roughly with the distance along the prehistoric global human migration route, the highest proportion being found in native South Americans.
This highly suggestive correlation is, of course, just that; it is not, by itself, an explanation of our peculiar human madness. We should not, however, underestimate the potential explanatory role that the genetics of a powerful neurocomputational factor such as dopamine can play in the future grand synthesis of insights into what it means to be human. Dismissing such findings can make one look as silly as the folks who thought up the tag line for the movie Dopamine (2003): "Is attraction/love/jealousy real... or just a chemical reaction?" As to the meaning of humanity — you can read more about this stuff, including the evolutionary and neurocomputational aspects of our urge for exploration, in my new book, whose title is the same as that of this blog.