If you had one hundred unlabeled DNA samples, taken from people all around the world, could you use that DNA to determine where the original donors came from?

With major improvements in genotyping technology, geneticists are now getting better and better at this game, and a recent paper in Science reports the largest study to date of human genetic diversity: 650,000 genetic differences scrutinized in nearly 1000 different individuals from 51 different populations.

Studies like this one lay important groundwork to help us understand how human genomes differ around the world, how differences in our genes and environments together make us healthy or sick, and how very ancient migrations led to the structure of today's human populations around the globe.

Wild sex is a staple of nature films, but there is one sex scene David Attenborough has never narrated: the mating ritual of yeast. That's right: yeast. Sex isn't just limited to lions, birds of paradise, and aphids; single-celled fungi do it too. Although most people don't like to hear the words 'fungus' and 'sex' used in the same sentence, yeast mating is a remarkable phenomenon and worth a closer look.

You can see this amazing scene, played out billions of times every day in wine vats and under oak trees, captured on film. As is the case with most wild mating rituals, filming yeast sex requires great patience - yeast are slow to commit and even when they do, they don't rush things. The beginning of foreplay itself takes several hours, as you can see below:

There is a particular narrative about science that science journalists love to write about, and Americans love to hear. I call it the 'oppressed underdog' narrative, and it would be great except for the fact that it's usually wrong.

The narrative goes like this:

1. The famous, brilliant scientist So-and-so hypothesized that X was true.

2. X, forever after, became dogma among scientists, simply by virtue of the brilliance and fame of Dr. So-and-so.

3. This dogmatic assent continues unchallenged until an intrepid, underdog scientist comes forward with a dramatic new theory, completely overturning X, in spite of sustained, hostile opposition by the dogmatic scientific establishment.

We love stories like this; in our culture we love the underdog, who sticks to his or her guns, in spite of heavy opposition. In this narrative, we have heroes, villains, and a famous, brilliant scientist proven wrong.

Interested in the strange, turn-of-the-century science and math in Thomas Pynchon's novel Against The Day? In part 2 of my primer on Pynchon's science read about the obscure conflict among mathematicians over quaternions, before modern vector analysis largely won the day. (If you missed part 1, read it here).

Science and Against The Day Part 2: Vectors and Quaternions

I. The need for algebra in more than one dimension

In Against the Day, Pynchon frequently refers to a relatively obscure conflict in the mathematics and physics community that took place in the early 1890's between advocates of quaternions and proponents of the newer vector analysis. This conflict is tied in to major themes in the book, such as the tensions between the old and the emerging world that culminated in the conflict of World War I, and the ability to perceive and describe the world in more than the three dimensions of Euclidean space. Quaternions, like the luminiferous aether discussed in Part 1 of this essay, became superfluous and obsolete, mostly unnecessary in the efforts of physicists to describe the natural world after the advent of modern vector algebra and calculus.