protozoan

The host of life on ice includes bacteria, viruses, fungi, protozoa, even microscopic animals like nematodes, some dead and some alive in suspended animation.

Organisms that can survive in this suspended, or anabiotic, state, Yarzábal explained, include not just extremophile bacteria but also viruses, fungi, protozoa and microscopic animals called nematodes.

It seems miraculous that, over billions of years, our planetary circumstances enabled protozoa to evolve into people.

Bottom line: If you must have tropical milkweed, cut it down to the ground each fall before it goes to seed, to kill any overwintering protozoa and reduce its potential to spread to neighboring areas.

Food turns into compost through the hard work of small microorganisms like bacteria, fungi, and protozoa.