Why two sexes evolved instead of more

Nick Lane has some pretty wild ideas about the evolution of life.

He thinks early life was continuous with the spontaneous chemistry of undersea hydrothermal vents.

Nick’s story may be wrong, but I find it remarkable that with just that starting point, you can explain so much about why life is the way that it is — the things you’re supposed to just take as givens in biology class:

* Why are there two sexes? Why sex at all?

* Why are bacteria so simple despite being around for 4 billion years? Why is there so much shared structure between all eukaryotic cells despite the enormous morphological variety between animals, plants, fungi, and protists?

* Why did the endosymbiosis event that led to eukaryotes happen only once, and in the particular way that it did?

* Why is all life powered by proton gradients? Why does all life on Earth share not only the Krebs Cycle, but even the intermediate molecules like Acetyl-CoA?

His theory implies that early life is almost chemically inevitable (potentially blooming on hundreds of millions of planets in the Milky Way alone), and that the real bottleneck is the complex eukaryotic cell.

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Timestamps

(00:00:00) – The singularity that unlocked complex life

(00:08:26) – Early life continuous with Earth's geochemistry

(00:23:36) – Eukaryotes are the great filter for intelligent life

(00:42:16) – Mitochondria are the reason we have sex

(01:08:12) – Are bioelectric fields linked to consciousness?

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