Since Darwin, we have pictured the environment as the fixed thing: it sets the test, and organisms adapt or die. But that is only half the loop. The beaver builds a dam and turns a stream into a pond. The spider spins a web; the bird weaves a nest; the earthworm rewrites the chemistry of the soil. Organisms are not passive. The environment is a product of organisms.
Biologists call this niche construction (Odling-Smee, Laland & Feldman), and it runs as a second engine of evolution beside natural selection. It even has its own inheritance: descendants receive not only genes but the world their ancestors built — a beaver born into the pond its grandparents dug.
So life does not only drift and sense. It builds — and the built world is handed on.