Evolution designed us to die fast; we can change that — Jacob Kimmel

**Dwarkesh Patel** (0:00)
Today, I have the pleasure of chatting with Jacob Kimmel, who is president and co-founder of NewLimit, where they epigenetically reprogram cells to their younger states. Jacob, thanks so much for coming on the podcast.

**Jacob Kimmel** (0:09)
Thanks so much for having me. Looking forward to the conversation.

**Dwarkesh Patel** (0:11)
All right. First question, what's the first principles argument for why evolution just discards us so easily? Look, I know evolution cares about our kids, but if we have longer, healthier lifespans, we can have more kids, or we can care for them longer, we can care for our grandkids. Is there some pleiotropic effect that anti-aging medicine would have, which actually selects against you staying young for longer? Yeah.

**Jacob Kimmel** (0:37)
I think there are a couple of different ways one can tackle this. One is you have to think about what's the selective pressure that would make one live longer, and encode for higher health over longer durations. Do you have that selective pressure present? There's another which is, are there any anti-selective pressures that are actually pushing against that? There's a third piece of this, which is something like the constraints of your optimizer. If we think about the genome as a set of parameters, and the optimizer is natural selection, then you've got some constraints on how that actually works. You can only do so many mutations at a time, you have to spend your steps that update your genome in certain ways. So tackling those from a few different directions, what would the positive possible selection be? As you highlighted, it might be something like, well, if I'm able to extend the lifespan of an individual, they can have more children, they can care for those children more effectively, that genome should propagate more readily into the population.
And so one of the challenges, then, if you're trying to think back in sort of a thought experiment style of evolutionary simulation here, would be what were the conditions under which a person would actually live long enough for that phenotype to be selected for, and how often would that occur? And so this brings us back to some very hypothetical questions, things like what was the baseline hazard rate during the majority of human and private evolution? The hazard rate is simply what is the likelihood you're going to die on any given day? And that integrates everything, that's like diseases from aging, that's getting eaten by a tiger, that's falling off a cliff, that's like scraping your foot on a rock and getting an infection and dying from that. And so from the best evidence we have, the baseline hazard rate was very, very high. And so even absent aging, you're unlikely to actually reach those outer limits of possible health where aging is one of the main limitations. And so the number of individuals in the population that are going to make it later in that lifespan, where using some of your evolutionary updates to try and actually push your lifespan upward, is relatively limited. So the amount of gradient signal flowing back to the genome then is not as high as one might intuitively think.

**Dwarkesh Patel** (2:29)
Right. By the way, just on that, often people who are trying to forecast AI will discuss basically how hard did evolution try to optimize for intelligence? And what were the things which optimizing for intelligence would have prevented evolution for selecting for at the same time, which would make it so that even if intelligence were a relatively easy thing to build in this universe, it would have taken evolution so long to get at human level intelligence. And potentially, if intelligence would be really easy, then it might imply that we're going to get to super intelligence and Jupiter level intelligence, etc., etc. The sky's the limit. So one argument, like birth canal sizes, etc., or the fact that we had to spend most of our resources on the immune system. But what you just sent that at is actually an independent argument that if you have this high hazard rate, that would imply that you can be a kid for too long. Because the kids die all the time, and you got to become an adult so that you can have your kids.

**Jacob Kimmel** (3:27)
Yeah, you got to contribute resources back to the group. You can't just be a freeloader. You need to get calories, go out in the jungle, get some berries.

**Dwarkesh Patel** (3:34)
If you're just hanging out, learning stuff for 50 years, you're just going to die before you get to have kids yourself. Obviously, humans have bigger brains and other primates. We also have longer adolescences, which help us make use potentially of the extra capacity our brain gives us. But if you made the adolescence too big, then you would just die before you get to have kids. If that's going to happen anyways, what's the point of making the brain bigger? AKA, maybe intelligence is easier than we think, and there's a bunch of contingent reasons that evolution didn't turn as hard on this variable as it could have.