Which is the most evolutionarily advanced part of the human brain?

This is a potentially controversial issue, since there is no consensus yet on the evolution of the brain, beyond a very coarse-grained chronology. Broadly speaking, neocortical areas are new, hence the term “neo-cortex”. But among cortical areas, there is still some disagreement about which areas emerged most recently in primates.

Based on what we know about development in the womb, along with structural findings, my labmates, who are neuroanatomists, suggest that the “eulaminate” areas — the ones that have sharply defined layers — may be the most recent, evolutionarily, compared to the “agranular” and “dysgranular” cortices, which have less sharply defined layers. These less sharply defined areas are also labeled as “limbic”.

Why is the brain so sensitive to early life experiences?

I was asked this question on Quora:

From an evolutionary standpoint, why would the early years of brain development be paramount in determining life-long neurological patterns, when those patterns can often be detrimental to long-term success in life?

Good question. We can restate it as follows:

Why would natural selection allow animals to be so sensitive to negative early experience?