The dinosaur on your plate: How turkeys conquered the world
When the asteroid struck the ocean off the Yucatan Peninsula 65 million years ago, a rain of molten glass and flaming rocks spread around the planet. The last day of the dinosaurs that populate childhood imaginations, and adult fascination, didn’t drag things out. They were dead in hours. Maybe minutes.
But some time after the ash settled and the fires went out, a small dinosaur stepped from the wreckage. With feathers and a toothless beak, this dinosaur was already a solid member of the surviving dinosaurs that we call “birds.” More than that, this was a heavy-bodied, stout-limbed bird that was more at home on the ground than in the trees. The kind of bird that can fly, but would really just prefer to walk. It was a Galliformes, the group that contains the modern turkey. And that group was already at least 20 million years old.
That’s right. The group that includes the bird on your Thanksgiving plate was around not just before the asteroid fell, but long before Tyrannosaurus rex evolved.
The biggest group of the dinosaurs-we-call-birds before that big space rock delivered a rain of fire followed by years of darkness were Enantiornithes. They carried their dinosauriness more openly, with teeth in their mouths and claws still hooking from their wings. They were a diverse and highly successful group, most of them clearly designed for the kind of flying-around, perching-in-trees lifestyle that most backyard birds adopt today. Still … they didn’t make it. Neither did the Hesperornithes, a group of swimming birds that took on forms similar to modern penguins or auks.
The Galliformes survived. So did the ratites, another group of mostly ground-loving birds like ostriches, emus, and other big flightless birds today. And there were also ancestors of the Neoaves, which make up 95% of all the birds that are still flapping, running, or swimming today. Though honestly, where all those other birds came from is harder to say.
The Neoaves got busy after the disaster, filling lots of birdy niches, but Galliformes pretty much had their role down from the beginning. Think about this lineup: quail, partridge, pheasant, chicken, guinea fowl, turkey, peafowl. From medium-small to medium-large, they’re all birds that stalk around forest and grasslands on foot, taking to wing mostly as a means of escaping predators. They’re all Galliformes.
One of these, the Red Junglefowl (Gallus gallus), better known to your local colonel as a chicken, is now the most common bird on the planet. At last count, there are about 24 billion of them — all but a tiny handful of which are caged up for human consumption.
Checking out a Butterball young white vs. the giant roaster chickens in the back of Costco shows the under-the-feathers similarity of these species. But within the group, chickens and turkeys (Meleagris gallopavo) aren’t particularly closely related.
Actually, despite the difference in size and sleekness, turkeys are closely related to pheasants. Think of a turkeys as a pheasant that made its way to North America, discovered a place where there were none of those pesky ratites hogging the big bird niche, and just … let itself grow. Thanks to a tough disposition, an omnivorous appetite (turkeys will eat seeds and berries, but also insects and snakes), and a surprising ability to get their heavy bodies up and out of there when need be, they’ve been one of the more successful large species across America for better than 2 million years. Turkey bones are even one of the most common finds in the La Brea tar pits, though that particular species, Meleagris californica, is now extinct.
But the evolution of turkeys didn’t stop when they made it to North America and realized they’d found a ratite-free paradise. Darwin devoted most of On the Origin of Species not to looking at how things evolved in the wild, but how they responded to human interference. Don’t worry, I’m not going to go on that long, but there are a couple of points worth pointing.
Starting around 2,000 years ago—and maybe a good deal earlier—turkeys were domesticated in Mexico. And that is where your turkey comes from. Mexico. Indirectly, every single grocery store turkey found chilling in the freezer today is descended not from a wild turkey someone cooped up in New England, but from a group of domesticated birds that Spanish conquistadors took from the Aztecs and shipped back to Europe.
That’s right. Whether the bird on your plate is a Broad Breasted White bred in massive numbers by one of the half-dozen dominant poultry firms, or some heritage breed hand fed on a small farm that gave it a great last meal before humanely calling it to a noble purpose, the ancestor of that bird was stolen during the conquest of Mexico and destruction of North America’s greatest indigenous empire.
There’s one slight variant on this. Narragansett turkeys are said to be the result of cross-breeding one of these spoils-of-war turkeys with wild relatives. So on that one count, depending on how you look at it, the guilt level may be halved.
The turkeys pardoned by President Joe Biden this year—named Peanut Butter and Jelly—are of the currently most common Broad Breasted White variety. By weight, they’re about twice as heavy as their wild relatives, topping out at around 40 pounds. They’re also structurally different, with breast bones that are proportionally shorter supporting breast muscle that is considerably larger. Breeding the birds generally requires human intervention (yes, “turkey baster” has more than one meaning).
Turkeys may have originated in America, but domesticated turkeys have become the official birds of celebratory feasts in countries around the world. Those birds taken from the Aztecs became favorites on the plates of the wealthy, often replacing their pheasant relatives, and became feast-day favorites everywhere. That leads to some 620 million turkeys getting slaughtered each year.
Which seems sad, but is one way of saying that turkeys have won the evolution game. They’ve gone from a few million birds walking around one continent to numbering in the billions and having a world-wide presence. On a planet where 96% of all large animals are either humans or the animals they have domesticated for consumption, that’s a win. The world is populated by the things we eat. Everything else, from antelope to lions to blue whales, has to squeeze into the remaining 4%.
I’m having my dinosaur with gravy.
A note to the one of you who is preparing to slap me for mixing up clades, families, and orders in laying out those evolutionary connections: slap away. But I already know.