The Geology of the Heart

Lake Victoria sits where the human aorta sits. The Nile drains where the descending aorta drains. Once you see one of these connections you can't stop looking.

In 2018, while drafting a chapter on the midbrain, I noticed something I had not been looking for: the contour of the Mesopotamian basin — the cradle of our earliest civilizations — sits, almost line-for-line, where the brain's earliest control centres do. I dismissed it. Coincidence. The brain is small; the planet is large; the human eye finds patterns in clouds.

But the next morning I drew it again, and the morning after that. Then I did the same with the aorta and the African Rift. Then with the Silk Road and the portal vein. The drawings kept rhyming.

The hypothesis of this chapter is small and unfashionable: when life emerges on a planet, it inherits the planet's body plan. Not metaphorically. Structurally.…