The brain developed a hierarchical structure through evolution by building off of its preexisting capabilities

Life began around 3.5 billion years ago. Multicelled creatures first appeared about 650 million years ago. (When you get a cold, remember that microbes had nearly a three-billion-year head-start!) By the time the earliest jellyfish arose about 600 million years ago, animals had grown complex enough that their sensory and motor systems needed to communicate with each other; thus the beginnings of neural tissue. As animals evolved, so did their nervous systems, which slowly developed a central headquarters in the form of a brain. The brain is a hierarchical system. Evolution builds on preexisting capabilities. Life’s progression can be seen inside your own brain. The highest-level parts—those developed late in our evolution, typically located in the cortex—exert an inhibitory influence on the lower-level limbic system and emotional-territorial circuit. Cortical tissues that are relatively recent, complex, conceptualizing, slow, and motivationally diffuse sit atop subcortical and brain stem structures that are ancient, simplistic, concrete, fast, and motivationally intense.


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Type:🔴 Tags: Biology / Neuroscience / Anatomy / Neuroanatomy Status:☀️