Nervous system in the cards

Years and years go by and front-loading evolution remains plausible.

This is an important paper, for it uses a novel method to show that the outgroup to all other animals is not sponges, as most people thought, but ctenophores. And that implies that nerves and muscles evolved twice independently. https://t.co/fLoJ7tN0GE

— Jerry Coyne (@Evolutionistrue) May 20, 2023

From the paper:

However, in the ctenophore-sister scenario supported here by deeply conserved syntenies, there are two possible alternatives explaining the evolution of neurons: either complex neural systems arose more than once^3,59,62 but were elaborated differently in ctenophores, cnidarians and bilaterians^3,4,59, or neuronal cell types were present in the metazoan ancestor but were lost in the sponge lineage^4,9,63.

The emergence of the nervous system doesn’t look like some freak accident.