free-living

It’s also a parasite — because who needs to be free-living when you’re this fabulous?

Nematodes are among the planet's most abundant animals, "free-living" in water, soil and the Earth's crust in addition to parasitizing a large collection of plant and animal species.

Photosynthesis takes place inside chloroplasts, small compartments within plant cells that contain their own genome, reflecting their past as free-living photosynthetic bacteria before they were engulfed and co-opted by plants.

The lifecycle of soil-transmitted helminths has two phases -- a free-living stage as eggs and larvae in the environment and an adult stage inside the host.

"It opens the door to experimentally manipulate the demographic or genetic composition of free-living populations to ask questions about how realistic natural social environments affect health, fitness and life outcomes for individuals," Sheehan said.