USP 2024 — Questão 23 · Língua Inglesa

TEXTO PARA AS QUESTÕES DE 21 A 23

Out of Sight, ‘Dark Fungi’ Run the World from the Shadows

If you want to discover a hidden world of new lifeforms, you don’t have to scour dark caves or slog through remote rainforests. Just look under your feet. When thengraduate student Anna Rosling went to northern Sweden to map the distribution of a particular root-loving fungus, she found something much more intriguing: Many of her root samples contained traces of DNA from unknown species. Weirder still, she never encountered a complete organism. When the field season ended, she had only isolated bits of raw genetic material. The fragments clearly belonged to the fungal kingdom, but they revealed little else. “I got obsessed,” recalls Rosling, now a professor of evolutionary biology at Uppsala University in Sweden.

Since then, mycologists have realized that such phantoms are everywhere. Point to a patch of dirt, a body of water, even the air you’re breathing, and odds are that it is teeming with mushrooms, molds and yeasts (or their spores) that no one has ever seen. In ocean trenches, Tibetan glaciers and all habitats between, researchers are routinely detecting DNA from obscure fungi. By sequencing the snippets, they can tell they’re dealing with new species, thousands of them, that are genetically distinct from any known to science. They just can’t match that DNA to tangible organisms growing out in the world.

These slippery beings are so widespread that scientists are calling them “dark fungi.” It’s a comparison to the equally elusive dark matter and dark energy that make up 95 percent of our universe and exert tremendous influence on, well, everything. Like those invisible entities, dark fungi are hidden movers and shakers. Scientists are convinced they perform the same vital functions as known fungi, directing the flow of energy through ecosystems as they break down organic matter and recycle nutrients. Dark fungi are prime examples of what biologist E. O. Wilson called “the little things that run the world.” But their cryptic lifestyle has made it a maddening challenge for scientists trying to show how exactly they run it.

Scientific American. June 21, 2024. Adaptado.

No que tange à observação do biólogo E. O. Wilson em relação aos fungos escuros, é possível inferir que