Mass of the Human Brain

Mass of the Human Brain

In biology there is a principle of powerful and if imperfect applicability called recapitulation: in our individual embryonic development we retrace the evolutionary history of the species.

All living things on our planet are constructed of organic molecules – complex microscopic architectures in which the carbon atom plays a central role. There was once a time before life, when the Earth was barren and utterly desolate. Our world is now overflowing with life. How did it come about? How, in the absence of life, were carbon-based organic molecules made? How did the first living things arise? How did life evolve to produce beings as elaborate and complex as we, able to explore the mystery of our own origins.

On the countless other planets that may circle other suns, is there life also? Is extraterrestrial life, if it exists, based on the same organic molecules as life on Earth? Do the beings of other world look much like life on Earth? Or are they stunningly different – other adaptations to other environments? What else is possible? The nature of life on Earth and the search for life elsewhere are two sides of the same question – the search for who we are.

About two-thirds of the mass of the human brain is in the cerebral cortex, devoted to intuition and reason. Humans have evolved gregariously. We delight in each other’s company; sometimes we even care for one another. We cooperate. Altruism is built into us.

We have brilliantly deciphered some of the patterns of Nature.

Probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed… There is grandeur in this view of life… that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

Charles Darwin, the Origin of Species, 1859.