A billion years of evolution in a single afternoon — George Church

**Dwarkesh Patel** (0:00)
Today, I have the pleasure of interviewing George Church. I don't know how to introduce you. It would honestly, this is not even an exaggeration, it would honestly be easier to list out the major breakthroughs in biology over the last few decades that you haven't been involved in. From the Human Genome Project to CRISPR, age reversal to de-instinction. So, you weren't exactly an easy prep.

**George Church** (0:21)
Sorry.

**Dwarkesh Patel** (0:21)
Okay, so let's start here. By what year would it be the case that if you make it to that year, technology in bio will keep progressing to such an extent that your lifespan will increase by a year, every year, or more?

**George Church** (0:34)
Escape velocity is sometimes what it's called for aging. Different people have estimates and all those estimates are, including mine, are going to be taken with a big grain of salt.
I think that mainly looking at the exponentials in biotechnology and the progress that's been made in understanding not just understanding causes of aging, but seeing real examples where you can reverse subsets of the aging phenotype. You're getting close to all of aging. In other words, you're seeing, instead of just saying, oh, I'm going to fix the damage in this collagen, in this tendon, in this limb, you're saying, oh, I'm going to change a lot of things that are common to aged related diseases, and I'm going to get more than one at a time. I think looking at those two phenomena, the exponentials in biotechnologies and the breakthrough in general aging, not just analysis, but synthesis and therapies, and a lot of these therapies are now making in the clinical trials. I wouldn't be surprised if 2050 would be a point, if we can make it to that point, 25 years. Most people listening to this have a good chance of making it 25 years. The thing is, it's not going to be some sudden point where you're going to be so sick 25 years from now that it's like hit or miss. It's more likely that you're going to be healthier 25 years from now than you thought you were going to be. There may be some, probably not some law of physics, but some economic or complexity issue that we don't know about that becomes a brick wall. I doubt it seriously, but we'll have to see.

**Dwarkesh Patel** (2:31)
Given the number of things you would have to solve to give us a lifespan of humpback whales.

**George Church** (2:37)
Bowhead whales, 200 years.

**Dwarkesh Patel** (2:39)
Is there any hope for doing that from somatic gene therapy alone or would that have to be germline gene therapy?

**George Church** (2:45)
Probably, there's a lot of forces pushing it towards somatic. For one, there are eight billion people that have missed the germline opportunity, as to say, doesn't apply to us, the two of us and everybody listening to this.
You have to be very cautious when you say something is impossible. It's safe to say it's impossible to do it this second, but you don't know what's going to happen tomorrow in the next decade or something. So I think there's a lot that could be done. In particular, since aging is a fairly cellular phenomenon with proteins going through the blood and other factors going through the blood, the signaling and so forth, you could imagine if you replaced, let's say, every cell in the body, every nucleus in the body, it would suddenly be young again, right, without going all the way back to the embryo and forward again. And there's various other things that are just short of that. If you replace the cells, well, they'll fit in to that niche. They might displace the old cells. That's certainly within the realm of modern synthetic biology is for cells to take over niches. I think the hardest part is the brain. But even there, there's some evidence that if you bring, even though the brain doesn't really use stem cells that much, you could artificially bring in stem cells and they could artificially fit into a circuit and learn the circuit and then displace the old ones in some way.

**Dwarkesh Patel** (4:25)
Shibathesius kind of thing in the brain?

**George Church** (4:26)
Yeah, exactly. Shibathesius.
Having, trying to maintain the connections and the memories. But there's some fairly straightforward experiments that need to be done before we can really even estimate how hard that problem is. Very often, there's low-hanging fruit that people just think is improbable, but it's there, because biology has all these gifts that, you know, where the, you know, just hands over to us levers that we can flip. Like vaccines is an amazing gift. It didn't have to exist, but they do, yeah.