Explore every episode of the podcast Molecules Made Me Do It: Life, the Mind, Sex and Future Cures

How did chemistry acquire memory — and become something that could truly evolve? In this third episode on the origin of life, we explore the RNA world, the first genes, protocells and the long path toward LUCA, the Last Universal Common Ancestor.

We move from messy, low-fidelity chemical networks to the idea of a portable molecular instruction manual. We look at how polymers can store information in their sequences, how complementary pairing allows that information to be copied, and why the first gene probably needed to be both useful and reproducible. RNA emerges as the prime candidate: unlike DNA, it can both carry information and catalyze chemistry, making it a plausible bridge between simple replicators and the first genetic systems.

Then we tackle two more crucial steps. First, recent work on a tiny RNA called QT45 shows just how small the machinery for RNA copying might be. Second, life had to learn to “herd the cats” by trapping useful chemistry inside membranes, creating protocells with an inside and an outside.

From there, RNA, proteins and eventually DNA could divide the labor, leading, about 4 billion years ago, to LUCA — the Last Universal Common Ancestor, the ancient cellular ancestor from which all modern life descends.

Molecules Made Me Do It is written and presented by Jeremy Smith. 

A popular-science podcast about the beautiful and devious molecules behind life, the mind, sex and the cures of the future. No scientific background required. 

Music written and performed by Jeremy Smith. 

Follow or subscribe to Molecules Made Me Do It wherever you get your podcasts.

How did life begin from lifeless chemistry? In this second episode on the origin of life, we explore how life began on the early Earth, starting with the famous Miller-Urey experiment, which showed that simple gases, water and energy could generate some of life’s basic organic building blocks.

But making molecules is not the same as making life. The deeper problem is how random chemistry could become organized without requiring one fantastically improbable stroke of luck. The answer may have been a long sequence of small chemical successes, each preserved and built upon rather than everything appearing at once.

We then follow one possible route: self-sustaining cycles of chemical reactions driven by continual energy, sped up by catalysts, and eventually able to make more of their own components. Once slightly different versions of these chemical networks could arise and some worked better than others, something resembling evolution could begin — even before genes and cells existed.

Autocatalysis, in which parts of a chemical network help make more of that same network, provides a tantalizing bridge between ordinary chemistry and the first primitive systems capable of reproducing and evolving.

Molecules Made Me Do It is written and presented by Jeremy Smith. 

A popular-science podcast about the beautiful and devious molecules behind life, the mind, sex and the cures of the future. No scientific background required. 

Music written and performed by Jeremy Smith. 

Follow or subscribe to Molecules Made Me Do It wherever you get your podcasts.

How did life begin on Earth? In this first episode of Molecules Made Me Do It, we explore the origin of life, the primordial soup and the sources of energy that may have driven the first steps from chemistry toward biology.

We begin, naturally enough, with sex — or more precisely, “aquasex.” An ancient Mesopotamian creation story imagined life beginning with the fertile mingling of fresh and salt waters, personified by the gods Apsu and Tiamat. Surprisingly, this provides a useful jumping-off point for asking what modern science thinks life actually is. We explore definitions from Jacques Monod and NASA, meet Darwinian evolution, and ask what distinguishes a living chemical system from flames, crystals and other things that display some lifelike properties.

We then travel back to the violent young Earth and its hypothetical primordial soup. Why wouldn't a mixture of the right chemicals simply turn into life if we waited long enough? The answer leads us into thermodynamics, entropy and the Second Law — and the loophole that allows life to create local order without breaking any laws of physics.

The missing ingredient is a sustained supply of usable energy, perhaps from sunlight, electrical discharges or hydrothermal vents. Finally, we return to Apsu and Tiamat and discover an amusing parallel: mixture plus generative energy producing something entirely new — what modern science would call an emergent phenomenon.

Molecules Made Me Do It is written and presented by Jeremy Smith. 

A popular-science podcast about the beautiful and devious molecules behind life, the mind, sex and the cures of the future. No scientific background required. 

Music written and performed by Jeremy Smith. 

Follow or subscribe to Molecules Made Me Do It wherever you get your podcasts.

Molecules Made Me Do It is a popular-science podcast about the awesome, ingenious and devious molecules behind life, the mind, sex, disease and the cures of the future.

It is presented by Jeremy Smith, a molecular biophysicist who has spent his career trying to understand how pesky little biological molecules work. It’s for literally anyone who is curious , irrespective of whether your last encounter with biology or chemistry was yesterday or an unpleasant middle school lesson several decades ago. No scientific knowledge is assumed! Atoms, molecules, proteins, genes  and all the other characters will be introduced as we meet them. The only prerequisite is that you don’t object to some wry humor thrown in with the serious stuff.

Everything we do is because molecules make us do it.

They make our cells work, allow us to see, think and remember, make us hungry, frightened, excited, sexy, and they make us ill. They poison us,  cure us and occasionally do both. What we do, think and feel is decided by villages of molecules working together, talking and scrapping with each other.

Molecules allow us to see, think, and feel. They make us hungry, frightened and sexy and they occasionally persuade us to do things that seemed an excellent idea at the time but considerably less so the following morning.

Evolution created these molecules and evolution is itself devious. It’s had billions of years to discover molecular tricks that no engineer would have thought of.

The results are molecules with distinct characters.

Some are elegant. Some are promiscuous. Some are ridiculously picky. Some are overly bureaucratic. Some are goon squads and vicious, pitiless destroyers and executioners. Others are comforters and peacemakers, and some are two-faced Gods. So  we’ll discover molecular personalities in the human body. 

Biological molecules are awesome, beautiful and dangerous. The elegant simplicity of DNA, amazing protein machines, pumps and channels – they’re structures of immense beauty and ingenuity.

But where did they all come from? Human beings have been wondering about that for a very long time. The ancient Mesopotamians had an explanation involving what might reasonably be described as aquasex.  We’ll start from aquasex and look at how the chemicals of the early Earth produced life,  and eventually  a little fellow named LUCA, the Last Universal Common Ancestor - the organism from which every living thing on Earth descended

We follow a certain unnamed biophysics professor who is at a party and happens to notice an outrageously attractive female across the room. What happens? We follow everything, from her divine photons entering his eyes, the chemistry of his desire: dopamine, noradrenaline, adrenaline. We’ll spend quite a bit of time on pleasure molecules  – can’t imagine why - and see how a society of molecules can have such impressive consequences for professorial dignity.

Then we turn to medicine. We’ll look at entertainingly nasty poisons and how they actually became medicines. Then we’ll look at how drugs are discovered today — and we’ll grumble at why the process is spectacularly inefficient, costing billions of dollars per drug and taking over a decade.

We’ll talk about what to do about that. Drug discovery is rapidly changing – we’ll see the brilliant new innovations taking place as we speak.  Finally, we’ll meet Pharmastradamus  - he’s Jeremy’s imaginary computer of the future, and he’s able to quickly pinpoint the right drugs and vaccines for anybody with no side effects. How might he do it? This is the medicine of the future: able to reverse aging, cure Alzheimer’s and cancer, create therapies that will change our genes, personalized medicines designed just for you.

Molecules Made Me Do It is written and presented by Jeremy Smith. 

A popular-science podcast about the beautiful and devious molecules behind life, the mind, sex and the cures of the future. No scientific background required. 

Music written and performed by Jeremy Smith. 

Follow or subscribe to Molecules Made Me Do It wherever you get your podcasts.