Nuchal Ligament

We can’t recommend a recent episode of the Radiolab podcast—Man Against Horse—highly enough.

It includes:

· Pigs on a treadmill

· Humans racing horses—on foot.

· A discussion about the role of the human butt.

· And a colorful discussion on a longstanding debate at the heart of human evolution.

If you know Radiolab (one of the best podcasts around), you know they find a way to make complex stories interesting and engaging. This episode is a classic.

It starts with a discussion of the butt muscle and leads to the existence of the nuchal ligament, long a point of fascination among evolutionary biologists.

The podcast includes Harvard’s expert, Daniel Lieberman, who has been around the “nuchal ligament” chatter for many years (since 1992).

Here’s how he describes his studies: “I'm interested in how and why our bodies are the way they are and the way in which we evolved.”

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So what’s up with the pigs? It turns out when they run that their heads flop around “in this kind of ungainly manner.”

Pigs don’t have a nuchal (nuchal: of the nape of the neck) ligament.

The nuchal ligament supports the head and neck.

Running animals have nuchal ligaments.

Jackrabbits? Yes.

Dogs? Yes.

Humans? But of course.

Apes? Nope.

Chimps and gorillas? Nope and nope.

Which leads us to human evolution.

Is running what made us human?

Or was it the ability to walk and the tools and brains?

The scientists studied the fossil record, to see if they can figure out when the nuchal ligament showed up.

Turns out,