The study of 58 species of songbirds also found that once a species evolved a larger brain, brain regions that control the beak and mouth, and the area for song, developed additional complex neural networks. . . .
The findings suggest that this principle may also help explain human evolution; we may have first evolved larger brains, which then allowed for adaptations that enhanced brain regions that control specific abilities, such as language.From here.
From a practical perspective, this makes the task of a would be trans-humanist attempting nootropic enhancements of the human genome straightforward. Select for a larger brain size and see what happens.
The paper is:
Jordan M. Moore, Timothy J. DeVoogd. "Concerted and mosaic evolution of functional modules in songbird brains." 284 Proceedings of the Royal Society B: Biological Sciences 1854 (May 10, 2007): 20170469.