https://www.sciencealert.com/study-of-1400-mammal-brains-suggests-a-rethink-on-studying-evolution-of-intelligence

(Shaun Wang/EyeEm/Getty Images)NATURE

MIKE MCRAE30 APRIL 2021

When considering matters of intelligence among animals, it’s not irrational to assume size matters. Bigger bodies allow for bigger brains, after all, and bigger brains provide the potential real estate for developing better problem-solving skills.https://4931270e8c88158002dfa667200c1c5c.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html

Yet neurons don’t work for free, a fact that constrains how nervous systems might evolve in size and complexity in the first place. Just because skulls expand, doesn’t mean nature will automatically fill them with grey matter.

Strange as it seems, we know very little about the evolutionary forces responsible for diversifying brain size across the backboned part of the animal kingdom.

So an international team of researchers undertook a huge study on the largest fossil and extant dataset yet assembled, measuring the spaces once occupying the skulls of more than 1,400 species, living and extinct.

Comparing information on body sizes with endocranial data, the…