Cortical evolution and human behaviour

Area of Science:

• Evolutionary developmental biology
• Neuroscience
• Paleoanthropology

Background:

• Mammalian behavior is complex yet stereotyped, unlike flexible human behavior.
• Understanding human behavioral flexibility involves evolutionary and developmental perspectives.
• Previous theories, like neoteny, have been refuted.

Purpose of the Study:

• To explore if human behavioral flexibility is an extension or departure from ancestral traits.
• To investigate evolutionary trends in mammalian isocortex development and their extrapolation to hominids.
• To debate the timing and nature of behavioral changes during hominid evolution.

Main Methods:

• Utilizing an evolutionary developmental biology approach.
• Analyzing the phylogeny and ontogeny of the six-layered mammalian isocortex, focusing on primates.
• Extrapolating brain evolution trends to hominids and citing paleoanthropological literature.

Main Results:

• Previous trends in isocortical evolution may not fully explain human behavioral flexibility.
• Human behavioral flexibility might involve departures from established evolutionary trajectories.
• Changes in later stages of isocortical development, especially the activity-dependent phase, are implicated.

Conclusions:

• Modern human behavior may not be a simple continuum of previous evolutionary trends.
• Departures in late-stage isocortical development, particularly connection refinement, are proposed as drivers of flexibility.
• Further research into activity-dependent phases of cortico-cortical connection refinement is warranted.