Frances H. Arnold’s speech at the Nobel Banquet, 10 December 2018.

Your Majesties,
Your Royal Highnesses,
Excellences,
Dear Laureates,
Ladies and gentlemen.

Let me start with a question: “Why did Newton’s apple fall to the ground?”

First the answer from the physicist: “There is a force called gravity that exists between any two objects, with a magnitude proportional to the product of the objects’ masses, and inversely proportional to the square of the distance between the centers of the masses. The apple is therefore propelled by this force towards the center of the earth when it leaves the tree.”

Now we will move to the answer from the evolutionary biologist: “Once upon a time, apples used to go in all directions, up, down, sideways – the world was full of ricocheting apples. However, only those apples that fell to the ground were able to germinate and grow new trees. Over millions of years, the forces of evolution selected for those apples which fell to the ground. Which is why apples now fall to the ground.”

We are three chemists who shamelessly expropriate from physics and biology (including their terrible jokes) to create molecules for the common good. We share deep admiration for evolution, a force of Nature that has led to the finest chemistry of all time, and to all living things on this planet. The fuel for evolution is diversity, with natural selection leading to continuous adaptations and improvements in Nature’s handiwork. Organisms (and organizations) without this diversity are doomed to extinction in a rapidly changing world.

Yet Nature has explored only a tiny fraction of the life and life’s molecules that are possible. With evolution in our hands, with the ability to set genetic diversity and to tailor the forces of selection, we can now explore paths that Nature has left unexplored. We can also explore paths that Nature will never explore: we can select living organisms and their chemistries for our benefit – to create new sources of energy, to fix the carbon in our atmosphere, to cure disease or to make us younger. Or we can make new weapons of terror or of state control … which shall it be?

The lesson from our apple joke: In practice and in theory, evolution is all too easy to apply incorrectly.

And so on behalf of all three laureates in Chemistry, whose recombined contributions evolved into tonight’s message, I propose a toast to evolution – may we use it well!