Blaise Agüera y Arcas: evaluation

Transcript context

…Yeah. I wanted to touch on the the because I said that the same thing on the show many times that inspired by Kenneth Stanley actually, that we see this monotonic increase in complexity and and and evolution. In in standard Darwinian evolution, there is no reason for things to become more complex. Right. So in other words, if you if you just do the spaghetti throwing at the wall thing, then you could get simplifications or complexifications, you know, and then they're they're equal. There's there's nothing to favor 1 over the other a priori. Yeah. So ordinary Darwinian evolution, you know, can can either make things simpler or more complex. But symbiogenesis, which is, you know, the the this coming together of parts to make wholes, and and these major revolutionary transitions that you just mentioned, this is the theory of Jor Sathmarie and John Maynard Smith that they published in Nature in 1995. They they only had it like 8 of them in their original paper and they've since extended it to maybe a dozen, you know, but things like single cells coming together to make bodies, individuals coming together to make colonies, the emergence of sexual reproduction, the endosymbiosis of chloroplasts and of mitochondria, there are few others. Right? Those are very clearly steps upward in complexity and and the reason that that it's trivial to prove that there are steps upward is because if you have a which is reproducing and can make more of itself, and you have b, which is reproducing and can make more of itself, think of them each as having a tape, right, that says how to make a me, then when they come together, the result has to both know how to make a and how to make b and how to put them together. And that little extra bit of information, how to put them together, is what makes the whole necessarily more complex than the parts. So that that is the the the latter. And and where where I go beyond what Smith and Sathamari say is that for them, major transitions are are a rare and exceptional event. But I I think that if you look more closely at the way biology works, that's just the tip of the iceberg. Those are just the really big transitions that involved, you know, 2 large, you know, highly consequential things, you know, merging in some way or or many cells, you know, merging into something qualitatively extremely different. But but when you look more closely, you see horizontal gene transfer in bacteria all the time. That's also a form of of symbiogenesis where, you know, parts of 1 thing get muddled up in another. You see horizontal gene transfer in eukaryotes like us all the time. Apparently, a quarter of the cow genome is this BoV b transposon which has jumped around among lizards and all kinds of other animals as well. Viruses do this all the time. They they, you know, retroviruses insert big chunks of their genomes into ours. And, you know, the the big shock when you look at at our genome when it was first sequenced in 2001 is that only 1 and a half percent of that is even, you know, our proteins. And what the hell is the rest of it? You know, that there's the junk DNA. Now, we know it's not all junk. t sequenced in 2001 is that only 1 and a half percent of that is even, you know, our proteins. And what the hell is the rest of it? You know, that there's the junk DNA. Now, we know it's not all junk. You know, a lot of it has regulatory functions and so on, but even so, that's a lot you know, there's a lot of other stuff in there. And a huge amount of it is retrotransposons and retroviruses that have been endogenized. They serve functional purposes in many cases. The mammalian placenta was made out of, a virus, related to, the RSV virus which fuses lung cells together and can make babies sick that fuses together the cells in our placenta to make this this this blood blood barrier. Or there's an ARC virus. We don't really understand how it works but it lives in our brains and we know that if we knock it out in mice they can't form new memories. And and it goes on and on, you know, and especially in the last decade, we we find more and more examples of functional instances of bits of genome from 1 thing ending up in another and changing it.…

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