The Physics Behind a Tardigrade's Lumbering Gait
Published:31 Aug.2021 Source:Rockefeller University
Plump and ponderous, tardigrades earned the nickname "water bears" when scientists first observed the 0.02-inch-long animals' distinctive lumbering gaits in the 18th century. Their dumpy plod, however, raises the question of why tardigrades evolved to walk at all.
Animals as small and soft as tardigrades seldom have legs and almost never bother walking. For example, round worms of similar size and body type thrash about, slithering their doughy forms over unpredictable substrates. Yet the water bear, a micro-animal so distinct that scientists were forced to assign it to its own phylum, uses eight stubby legs to improbably propel itself through marine and freshwater sediment, across desert dunes, and beneath the soil.