Some living things, when faced with a drought, do more than just survive. When water disappears,
they can cheat death itself through a kind of resurrection.
Look closely at this tree, baked by the California sun.
It’s covered in moss. And living in that moss is a microscopic animal called a rotifer.
When there’s no rain, the moss and the rotifers dry out. The rotifers stop eating. The mosses
stop photosynthesizing. They’re reduced to a pile of chemicals. They can stay that
way for years, even 100 years.
When the rain comes, the mosses spring back to life in seconds, using a rare ability.
Right before they dried out they wrote themselves a set of genetic instructions, so that if
they ever got water again they could start producing proteins –
and growing – right away.
Scientists call them “resurrection plants” and they hope to use their genes to engineer
crops that could repair themselves after a dry spell.
So why do mosses work this way?
Well, here’s the inside of a blade of grass. See those tiny tubes around the perimeter?
Those are for moving water up from its roots.
But mosses don’t have roots. Their porous cells absorb water like a sponge,
whenever it’s available.
For mosses and rotifers, it’s feast or famine.
When it rains, the water activates the rotifers’ metabolism and they need to fuel up.
They use the crown of cilia on their head to create a current to suck in all the algae
and bacteria they can. They grind this food up with their jaws. See the jaws? They look
like a tiny beating heart.
Rotifers, mosses – they’re experts at living without water.
And maybe in this miniature “resurrection kingdom” researchers will find clues for
how the crops we humans depend on might survive a dry Californian future.