This week, using genetically modified yeast to make opiates and the need for regulation now.

It does actually happen if they actually make a unified yeast strain,

or they unify the opiate pathway in a single agent,

that all hell will break loose.

And the oldest stone tools ever found.

I could immediately see the scars and the features characteristic of knapped stones,

but they were also different.

Plus the benefits of being choosy about who you sleep with.

This is the nature podcast for May the 21st, 2015.

I'm Kerry Smith.

And I'm Adam Levy.

In the hit TV series Breaking Bad, the main character, Walter White, is a chemistry teacher.

He falls on hard times and turns to making the drug methamphetamine to make ends meet.

You know the business, and I know the chemistry.

I'm thinking maybe you and I could partner up.

You want to cook crystal meth?

That's right.

The series portrays a homespun setup.

Their meth lab is in a bus.

In the real world, too,

meth production is often small scale and decentralized, whereas other substances, like opium,

for instance, are more often produced in just a few places in large quantities, legally or illicitly, and then shipped. But that could easily change.

...