Developmental Modes and Developmental Mechanisms can Channel Brain Evolution

Developmental Modes and Developmental Mechanisms can Channel Brain Evolution

Anseriform birds (ducks and geese) as well as parrots and songbirds have evolved a disproportionately enlarged telencephalon compared with many other birds. However, parrots and songbirds differ from anseriform birds in their mode of development. Whereas ducks and geese are precocial (e.g., hatchlings feed on their own), parrots and songbirds are altricial (e.g., hatchlings are fed by their par...

Developmental mechanisms channeling cortical evolution.

Increase in the area and neuron number of the cerebral cortex over evolutionary time systematically changes its computational properties. One of the fundamental developmental mechanisms generating the cortex is a conserved rostrocaudal gradient in duration of neuron production, coupled with distinct asymmetries in the patterns of axon extension and synaptogenesis on the same axis. A small set o...

Brain Evolution: Developmental Constraints and Relative Developmental Growth

Developmental structure in brain evolution.

How does evolution grow bigger brains? It has been widely assumed that growth of individual structures and functional systems in response to niche-specific cognitive challenges is the most plausible mechanism for brain expansion in mammals. Comparison of multiple regressions on allometric data for 131 mammalian species, however, suggests that for 9 of 11 brain structures taxonomic and body size...

Developmental constraints on or developmental structure in brain evolution?

The more we discover about the basic structure of vertebrate and invertebrate evolution, the more impressive the evidence of its conservative nature becomes. Evidence for commonalities versus special adaptations in brain evolution, with particular attention to rules for the proliferation of the cortex will be discussed. Conserved developmental rules that produce highly predictable brain organiz...