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All posts for the day February 14th, 2017

Now for the National Geographic post I had attempted back on the 12th:

Restless Genes, by David Dobbs

At first, I thought that this would be a rehash of what we covered back on June 29, 2016 or that the magazine would cover again in June of 2013, depending on your perspective. The thesis in that issue was that people take risks because they get a dopamine rush from it.

Instead, though, we talk about the possible genetic impetus and benefits of exploration. Dobbs discusses how unusual homo sapiens sapiens is for our desire to explore and to cover new territory. Other species may travel with us (rats and cockroaches, for example), but it’s doubtful whether those species would have spread out that far without us. Even our other homo sapiens cousins (such as the Neanderthal) didn’t spread out and conquer the world like we did.

We start out with one gene, DRD4, which controls dopamine (this is where I thought the two articles would overlap). A variant called DRD4-7R seems to correlate highly with exploration. But for all of the studies that seem to make that correlation, there are others that refute it.

One of the scientists who discovered the 7R variant believes that it is a collection of genetic changes, not just that one, that leads humanity to explore. We are better-suited than our primate cousins to walk far distances, and our brains take longer to develop but end up larger than theirs are. And even the long time it takes us to mature may help. Our long childhoods lead us to develop imaginations, which feed our curiosity and lead children to naturally become scientists and explorers. Some of us retain those tendencies into adulthood.

And explorers tend to breed new explorers. A community in Quebec spread out into the wilderness and as they progressed farther into the wilderness, the communities they founded had different traits. They married younger and had more children, and those children married younger and had even more children. Lawrence Excoffier, a population geneticist, believes that this sort of sorting happened over and over throughout human history, leading explorers to perhaps have had more children, and thus had a stronger impact on the human genome in general.

We start and end the article, and possibly also the story of human migration, with the population of the South Pacific. These peoples were the descendants of some of the first to leave Africa. Once they reached the end of the continent of Asia going westward, they started moving from through the islands in small canoes, always within sight of another island. But when they reached the end of the chain of islands that were “intervisible,” they stopped until centuries later, when people from somewhere else, perhaps Taiwan, brought a larger boat that could travel farther distances. And after that, nothing stopped them from conquering that entire part of the world.

Crazy Far, by Tim Folger photographs by Stephan Martiniere

We begin this article with a discussion of the NERVA project, which was an attempt to get humans to Mars in a nuclear-powered spaceship. The original plan was to leave for Mars in 1981. Obviously, we never got there.

In this article, we discuss the technology that could, someday, bring that old dream back to life, including nuclear fusion or a giant sail that would catch solar winds (Hey! I was just reminiscing about that Classic Doctor Who episode!)

The article concludes with the idea that before we can build a starship, though, we will need to build a society that will build a starship. That seemed like a good prospect in 2013. In 2017, I think we’re likely to take a big step backwards before we can even start on that project.