It was called survival of the fattest.

Roughly 15 million years ago, the shaggy A-plike ancestors of human beings faced a crisis.

The climate was getting colder, which killed off the fruit trees that our ancestors needed for food.

They faced sure starvation.

Then, a little mutation changed everything.

The mutation affected the way our bodies used sugar.

Specifically, the mutation allowed us to convert sugar into fat more easily.

Now, at the time this mutation benefited us.

As fruit trees died off and fruit got scarier, the mutation allowed us to ring more calories from food by converting it to fat to store for later.

This extra fat was often the difference between starving and surviving.

Hence the term survival of the fattest.

But we don't live in that ancient environment anymore.

And that once beneficial mutation seems to be fueling terrible health epidemics today, including skyrocketing rates of obesity, diabetes, and even cancer.

And that's not all.

Sugar helps shape the modern world in other awful ways too, from slavery to the holiday cost.

People talk sometimes about blood diamond.

It's an other natural resources whose extraction causes huge misery.

Well, today we're going to give the phrase blood sugar, a whole new meaning.

From the Science History Institute, this is Sam Keane and the Disappearing Spoon, a topsy, turvy, science-y history podcast, where footnotes become the real story.

For most of human history, sugar came from sugar cane.

A plant native to New Guinea.

Cain is technically a grass, although a grotesque one.

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