Evolution didn't just "invent" the brain once; it seems to have reinvented the entire neuron toolkit over and over again.
April 16, 2026
Original Paper
Evolutionary principles underlying neuron subtype encoding and diversification in animals
bioRxiv · 10.64898/2026.04.13.718258
The Takeaway
We always assumed that the specific types of neurons in a human brain were basically the same as the ones in a fly or a worm, just "upgraded." This study shows that neurons across different animal groups bear almost no resemblance to each other at a molecular level. It suggests that nature didn't have one master blueprint for a brain cell; instead, different species evolved their own unique types of neurons independently. This challenges everything we thought we knew about the ancestry of our own thoughts. It means our brains aren't just advanced versions of a worm's—they are a completely different kind of biological hardware.
From the abstract
Animals harbor a diversity of terminally differentiated cell types. This cell type diversity is particularly spectacular in the nervous system. While the shared evolutionary origin of the bilaterian neuron has been increasingly supported, it remains poorly understood when the first neuron diversified into the many types present in extant lineages and what molecular mechanisms accompanied this neuron diversification. Existing models of neuronal evolution are based on select observations from flie