The central thesis of Yong's work is that "individuals" do not exist in isolation. Every animal, from the Hawaiian bobtail squid to humans, is an "ecosystem on legs". We are teeming with trillions of microbes that outnumber or at least rival our own human cells, functioning as an interconnected, interdependent whole. This perspective shifts our identity from a single organism to a thriving, complex colony of life. Microbes as Biological Architects

They "sculpt" our organs and guide physical development from birth.

Microbes are not passive passengers; they are active builders and defenders:

Some deep-sea creatures without mouths or guts rely entirely on microbes for energy.

Bacteria help us digest food, break down toxins, and even influence our behavior and moods by interacting with our nervous system. A Grander View of Life

Microbes can bombard their hosts with genes, effectively modifying the genetic makeup and evolution of the species they inhabit. The Human Impact