In case you want to go even further down this particular rabbit hole, I did some more reading about this claim:
> So we need one sex that specializes in preserving mitochondrial quality, and another which is just there to provide the variance that sexual reproduction depends on.
> And there’s no benefit to a third sex. There’s two useful niches: either you transmit mitochondria or you don’t. A third sex would just be redundant with one of the first two.
There are plenty of eukaryotes who reproduce sexually with more than two "mating types", which are analogous to sexes. Some of these are multicellular, like the split-gill mushroom (Schizophyllum commune) which has over 20,000 mating types.
Nick Lane himself is an author on this paper[1] which concludes that "[uniparental inheritance] of mitochondria alone is unlikely to have driven the evolution of two mating types in unicellular eukaryotes." Another paper[2] proposes a model that explains the distribution of mating type numbers with only three parameters (mutation rate, population size and the rate of sex), none of which are related to mitochondrial fitness.
On the panspermia idea hear me out. Alien park rangers (or meteors) were seeding sea vents with the prerequisite dna, rna and such. Why not just start with the cell you ask? …. I got nothing
I'm jealous! Nick's story of our origins is magnificent and coherent. And to spend a few hours with that voice and those eyebrows. Well done!
In case you want to go even further down this particular rabbit hole, I did some more reading about this claim:
> So we need one sex that specializes in preserving mitochondrial quality, and another which is just there to provide the variance that sexual reproduction depends on.
> And there’s no benefit to a third sex. There’s two useful niches: either you transmit mitochondria or you don’t. A third sex would just be redundant with one of the first two.
There are plenty of eukaryotes who reproduce sexually with more than two "mating types", which are analogous to sexes. Some of these are multicellular, like the split-gill mushroom (Schizophyllum commune) which has over 20,000 mating types.
Nick Lane himself is an author on this paper[1] which concludes that "[uniparental inheritance] of mitochondria alone is unlikely to have driven the evolution of two mating types in unicellular eukaryotes." Another paper[2] proposes a model that explains the distribution of mating type numbers with only three parameters (mutation rate, population size and the rate of sex), none of which are related to mitochondrial fitness.
[1] https://royalsocietypublishing.org/doi/10.1098/rspb.2013.1920
[2] https://www.nature.com/articles/s41559-018-0580-9
I absolutely love these notes! Thank you :)
Thanks for sharing Dwarkesh! Excited for the episode
Quick edit: in your sentence 'Why Archaea and Bacteria (the two different kingdoms of eukaryotes)' I think you meant 'prokaryotes'
On the panspermia idea hear me out. Alien park rangers (or meteors) were seeding sea vents with the prerequisite dna, rna and such. Why not just start with the cell you ask? …. I got nothing