The Parable of the Musicians

Once there were three musicians who suddenly found themselves amidst a huge orchestra, mid-concert. They couldn’t quite recall how they had come to be there. They couldn’t remember asking to participate. Their music stands were empty and the piece unfamiliar. Indeed, there was no conductor and everyone seemed to be improvising. And yet, the three bewildered musicians were extremely talented, they had been presented with instruments of the highest quality, and the symphony playing around them was exquisite. They knew they must immediately join in. Somehow.

Continue reading “The Parable of the Musicians”

Survival of the Fittest, in First Person

Corona the pest

So far this year, over 180,000 people have died from COVID-19, including 48,000 Americans. Including my grandmother. Perhaps including someone you knew and loved. In the broad sense, this is nothing new. The story of our species, in fact the story of multicellular life on Earth, has been first and foremost one of battle against infectious disease. There have always been victims. The fittest survive. Germs have shaped our evolution and made us who we are. And yet. None of that is very comforting when you experience it firsthand. For all that I’m fascinated by natural selection, I don’t want it anywhere near my family.

Continue reading “Survival of the Fittest, in First Person”

Pestilence Prevails

The rider remains relevant

I enjoyed the novel Good Omens and the recent eponymous TV miniseries. In it, the biblical Four Horsemen of the Apocalypse return to modern-day Britain. Although the Book of Revelations never actually says so, one of the Horseman is traditionally thought of as Pestilence. That is, infectious disease. However, authors Pratchett and Gaiman reasoned that germs have been largely defeated and make for a lame villain. So, they replaced Pestilence with Pollution. Unrelatedly, this XKCD comic also suggests that Pestilence has been slain, and nuclear weapons have taken up the saddle. This trope is increasingly common. The Horsemen, it is thought, require an update. We destroyed Pestilence with antibiotics and vaccines, right? Pestilence is downplayed, seen as obsolete, or just ignored.

I have two points in reaction. First, personifying Pestilence is actually a useful way to understand history. Pestilence has been the human adversary. The scoundrel has slaughtered far more people than all other causes combined, and sealed the fates of nations over the millennia. Yet we hardly ever tell this story as a story, with a concrete antagonist. Pestilence taps our body fluids like a vampire. Pestilence pulls the strings during key events on the world stage. Pestilence suffers our attacks, and bounces back. The bouncing back part is the basis for my second point. Pestilence isn’t dead. Pestilence has been shackled by modern medicine, but all of that work could still come undone. As the global population becomes denser and more interconnected, we become easy fodder for the next big plague. Only with constant vigilance do we retain the upper hand. And all of this makes for an epic drama. This war has been the main story of our species. Yet, bizarrely, it’s rarely told.

Continue reading “Pestilence Prevails”

Purple President Polarized

Why don’t you just meet me in the middle?

In The Red Queen and the Purple President, I pondered about a weird phenomenon. In most animal species (and many non-animals) there are two sexes. In American politics, and similar winner-take-all electoral systems, there are two parties. These dichotomies are extremely stable over time. This observation may seem trivial, since it’s so entrenched in our everyday lives. However, it’s actually difficult to explain. Why aren’t intermediate forms more successful? Where are all the hermaphrodites? And centrists? And centrist hermaphrodites? I mused that there are no good simple mathematical models to explain this paradox.

Then the 2016 election happened. American politics seemed less like a curious abstraction and more like getting hit by a train. I never followed up on my post. But now that we’ve had a chance to at least catch our breath, let’s take up my challenge. Let’s create a model. You have to think about a little math first, but then we’ll get to some sweet animations.

Continue reading “Purple President Polarized”

Pellets and Pipeworks

Falx friends

“My fellow scientists, I bring you astounding news. I have discovered an intelligent species on another planet. In form they are little more than a network of pipes filled with fluid. But these Pipeworks have created a rudimentary civilization, complete with art and scholarship. More remarkable still is their ecology. Though they interact with various other species including prey, pests, commensals, decomposers, and so on, those can largely be ignored as superfluous details. The overarching narrative of Pipework history is one of an ongoing battle with a single other life form. This second creature is smaller, less brainy but more elusive, resembling a rounded pellet. The Pellets and Pipeworks have been at war for tens of thousands of years. Pipeworks have been slaughtered by Pellets in such monstrous numbers that death by any other cause, including murder by other Pipeworks, pales in comparison. The Pipeworks have both invented and evolved striking tactics for evading the Pellets, but always with mixed success. The conflict touches all. The great stories of Pipework history. The fates of their societies. The Pipework nations that have prospered while others have crumbled. Everything has depended on when and where Pellet sieges have been the most devastating. To this day, despite all of their technological advances, the Pipeworks have been unable to win the war, and hundreds of millions of them suffer Pellet attacks. However, for the first time in Pipework existence, victory seems to be within their grasp. If they unite as a species and face their ancient enemy, they may succeed in driving the Pellets to extinction. If they do, it will surely be their single greatest achievement, a vindication of all of their struggles. Simultaneously, it will be a bittersweet loss of their steadfast partner in the coevolutionary dance. Regardless, it will usher in an era of relief and resolution that will define them from that point onward.


“Following protocol, I also provide the relevant terms in the local dialect. The Pipeworks refer to themselves as Humans, the Pellets are called Plasmodium, and affliction with Pellets is a condition known as Malaria.”

Continue reading “Pellets and Pipeworks”

Gender, Genetics, and Generalizations

What are your X and Y coordinates?

It all started on Twitter. Again.


Briscoe Cain, a Republican in the Texas state legislature, tweeted this back in December:


I replied, correcting him, and my tweet went viral. You may be surprised to learn that people on the Internet frequently have strong opinions about gender. Lots of folks chose to spend their winter holiday sending me feedback. I explained things further on Twitter, but there’s a limit to the medium. So let’s break it down here, in one easy-to-read place.

Continue reading “Gender, Genetics, and Generalizations”

Green Red Herring on Your Plate

Don’t let the red distract you from the green

I’ve always tried to be intentional about food. I’ve been a vegetarian for nineteen years. I buy organic when it’s affordable and available. I shop locally at farmers’ markets and grocery co-ops. When I was in college and somewhat full of myself, I congratulated myself on my enlightened logic and morals. Today, I’m less convinced that I have stumbled upon the optimal diet for planetary and personal health. Nor am I making a martyr of myself. Truth is, I like what I eat. If tomorrow someone discovered that the most sustainable meal is actually giblet gravy and steak, I’d have a pretty hard time making the switch. Try as we might, food choices are never perfectly rational. Even for the most dispassionate egghead, what we put into our mouths is inseparably tangled up with culture, tradition, emotion, and of course personal taste. I strive to remember this while trying my best to eat ethically.


I’m not the only conscientious diner out there. But rather than feeling empowered, I’m actually a bit dismayed by many of my fellow Michael Pollan fans. The broader movement has become bizarrely focused on my own field of genetics. And not in a sensible way. For countless activists, genetic modification represents the ultimate bogeyman, the apex of all that is wrong with irresponsible agribusiness. The opposite of green. To me, and indeed to almost everyone who understands the science behind biotechnology, this animus appears nonsensical. Genetic modification is simply a tool. Like any tool, it can be applied in helpful or harmful ways. Yes, some unsustainable farming practices involve genetically modified organisms (GMOs). And some involve farmers named Steve. But surely it wouldn’t help anything to rail against all the agrarian Steves in the world. The anti-GMO movement stands on similarly shaky justification.

Continue reading “Green Red Herring on Your Plate”

The Origin Story of Species

Never fear, Hu-Man is here.

I’ve been thinking about origin stories. I love them, and so do a lot of folks. Consider the heroes of literature, from King Arthur to Harry Potter. Their iconic introductions, the way these protagonists became special, are a big part of why their stories ever grew popular in the first place. Religious heroes, too, are imbued with special beginnings. The nativity of Jesus is one of the most beloved stories in the world, and figures like the Buddha and Confucius have been assigned similarly magical infancies. As an evolutionary biologist, I deal with origins a lot. The history of life on Earth is just one big origin story. The word “Origin” is right there in the title of Darwin’s famous book, after all. Now, you might say, “Science is science, and fiction is fiction, and they have nothing to do with each other.” But that’s not really true. As the novel Ishmael cleverly illustrates, even the most factually correct description of the past is still mythical, because we ignore most facts and emphasize others. We construct narrative. Telling stories is a fundamental part of how humans make sense of the world. We can’t help it.

Continue reading “The Origin Story of Species”