Michael Levin: Biology, Life, Aliens, Evolution, Embryogenesis & Xenobots | Lex Fridman Podcast #325

It turns out that if you train a planarian and then cut their heads off, the tail will regenerate a brand new brain that still remembers the original information. I think planaria hold, uh, the answer to pretty much every deep question of life. For one thing, they're similar to our ancestors, so they have true symmetry. They have a true brain. They're not like earthworms. They're, you know, they're a much more advanced life form. They have lots of different internal organs, but they're these little, um, they're about, you know, maybe two centimeters and, and a centimeter to two in size. They have a bra- a head and a tail, and the first thing is planaria are immortal. So they do not age. There's no such thing as an old planarian. So r- that right there tells you that these theories of thermodynamic, um, limitations of, on lifespan are wrong. It's not th- it's not that, well, over time of g- everything degrades. No. Planaria can keep it going for, uh, probably th- you know, how long have they been around, 400 million years? Right? So these are the actual l- so the planaria in our lab are actually in physical continuity with planaria that were here 400 million years ago.

The following is a conversation with Michael Levin, one of the most fascinating and brilliant biologists I've ever talked to. He and his lab at Tufts University works on novel ways to understand and control complex pattern formation in biological systems. Andrej Karpathy, a world-class AI researcher, is the person who first introduced me to Michael Levin's work. I bring this up because these two people make me realize that biology has a lot to teach us about AI, and AI might have a lot to teach us about biology. This is the Lex Fridman Podcast. To support it, please check out our sponsors in the description, and now, dear friends, here's Michael Levin. Embryogenesis is the process of building the human body from a single cell. I think it's one of the most incredible things that exists on Earth from a single embryo. So how does this process work?

Yeah. It is, it is an incredible process. Uh, I think it's maybe the most, uh, magical process there is, and, uh, I think one of the most fundamentally interesting things about it is that it shows that each of us takes the journey from so-called just physics to mind, right? Because we all start life as a single, uh, quiescent unfertilized oocyte, and it's basically a bag of chemicals, and you look at that, and you say, "Okay. This is chemistry and physics." And then nine months and some years later, you have an organism with high-level cognition and preferences and, um, an, an inner life and so on. And what embryogenesis tells us is that that transformation from physics to mind is gradual. It's smooth. There is no, uh, special place where, you know, a lightning bolt says, "Boom, now you've gone from, from physics to true cognition." That doesn't happen. And so we can see in this process that of the whole mystery, you know, the biggest mystery of the, of the universe basically, how you get mind from matter.