Brain expansion: primate embryology causes expansion (Evolution)

by David Turell , Friday, October 02, 2020, 21:01 (1511 days ago) @ David Turell

It is in the way our genes control it:

https://www.sciencedirect.com/science/article/pii/B9780128040423000750?dgcid=raven_sd_r...

Abstract
Primates delay neocortical neurogenesis and possess more neocortical neuron numbers compared with other studied taxa. We consider the consequences of evolutionary changes in developmental schedules on neuron numbers and expression of genes to identify evolutionary changes in cortical circuitry in primates. Delays in neocortical neurogenesis account for the expansion of neocortical neuron numbers and concomitant differences in laminar gene expression patterns between the neocortex of primates and rodents. Some of these differentially expressed genes are synaptic-related and reflect changes in connectivity patterns. We suggest that developmental timing accounts for greater intracortical connectivity in primates compared with other mammals.

Comment: The genes control the development. No surprise