Science & technology | You are legion

The idea of “holobionts” represents a paradigm shift in biology

These meta-organisms are made up of animals, plants, and the microbiota that live on and inside them

Image: María Medem
|Boston and London

“How many cells are there in a human being?” It sounds like a question from a nerdy pub quiz. It is also a profound philosophical inquiry. One answer is around 37trn. This is the number, in a typical adult weighing 70kg, that trace their descent from the fertilised egg which brought that human into existence.

This article appeared in the Science & technology section of the print edition under the headline “What is an organism, anyway?”

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