(NYT Magazine) The Mysterious, Deep-Dwelling Microbes That Sculpt Our Planet

Scientists like [Magdalena] Osburn have shown that, contrary to long-held assumptions, Earth’s interior is not barren. In fact, a majority of the planet’s microbes, perhaps more than 90 percent, may live deep un­derground. These intraterrestrial microbes tend to be quite different from their counterparts on the surface. They are ancient and slow, re­producing infrequently and possibly living for millions of years. They often acquire energy in unusual ways, breathing rock instead of oxy­gen. And they seem capable of weathering geological cataclysms that would annihilate most creatures. Like the many tiny organisms in the ocean and atmosphere, the unique microbes within Earth’s crust do not simply inhabit their surroundings; they transform them. Subsurface microbes carve vast caverns, concentrate minerals and precious metals and regulate the global cycling of carbon and nutrients. Microbes may even have helped construct the continents, literally laying the ground­work for all other terrestrial life.

Like so much about Earth’s earliest history, exactly where and when life first emerged is not definitively known. At some point not long after our planet’s genesis, in some warm, wet pocket with the right chemistry and an adequate flow of free energy — a hot spring, an impact crater, a hydrothermal vent on the ocean floor — bits of Earth rearranged themselves into the first self-replicating entities, which eventually evolved into cells. Evidence from the fossil record and chemical analysis of the oldest rocks ever discovered indicate that microbial life existed at least 3.5 billion years ago and possibly as far back as 4.2 billion years ago.

Among all living creatures, the peculiar microbes that dwell deep within the planet’s crust today may most closely resemble some of the earliest single-celled organisms that ever existed. Collectively, these subsurface microbes make up an estimated 10 to 20 percent of the biomass — that is, all the living matter — on Earth. Yet until the mid-20th century, most scientists did not think subterranean life of any kind was plausible below a few meters.

Read it all.

We know SO little about our earth. Many wonderful quotable passages. An important article.

The Mysterious, Deep-Dwelling Microbes That Sculpt Our Planet https://t.co/vh4XXYNIgW

— sammyzorba 📚 (@sammyzorba) June 25, 2024