Going to Hell (Hades) to study microbial evolution

[sfmatheson (Stephen Matheson)]

Some scientific articles are must-reads because of what the scientists accomplished or developed. Some scientific articles are must-reads because of what the scientists discovered. And then some scientific articles are must-reads for both reasons. Here’s an example from a few weeks ago. A group of scientific teams in China worked for years to develop a vehicle that could carry researchers to Hell and back, so they could bring back dirt and animals from Hell. Then they went to Hell, brought back soil, and extensively analyzed the microbial communities in Hell. They discovered that these communities are dramatically distinct from communities in the nearby ocean, and thereby illuminated surprising evolutionary trajectories of the microbial organisms that inhabit Hell.

I’m overdramatizing. The scientists didn’t visit Hell. They visited Hades, which is mythologically different. Okay fine, their inspiring and successful mission went to the hadal zone of the ocean (named, aptly, after the dark underworld of Hades), specifically to the mysterious chasms of the Mariana Trench that are nearly 11,000 meters (about 6.8 miles) deep. Somehow, amazingly, microbes can live and reproduce and evolve at that depth. Maybe they’re even happy.

This is the graphical abstract from their Cell paper:

Here is the abstract. I think it’s a bit too understated, but it is inspiring nonetheless, and we can all use some inspiration right now.

Systematic exploration of the hadal zone, Earth’s deepest oceanic realm, has historically faced technical limitations. Here, we collected 1,648 sediment samples at 6–11 km in the Mariana Trench, Yap Trench, and Philippine Basin for the Mariana Trench Environment and Ecology Research (MEER) project. Metagenomic and 16S rRNA gene amplicon sequencing generated the 92-Tbp MEER dataset, comprising 7,564 species (89.4% unreported), indicating high taxonomic novelty. Unlike in reported environments, neutral drift played a minimal role, while homogeneous selection (HoS, 50.5%) and dispersal limitation (DL, 43.8%) emerged as dominant ecological drivers. HoS favored streamlined genomes with key functions for hadal adaptation, e.g., aromatic compound utilization (oligotrophic adaptation) and antioxidation (high-pressure adaptation). Conversely, DL promoted versatile metabolism with larger genomes. These findings indicated that environmental factors drive the high taxonomic novelty in the hadal zone, advancing our understanding of the ecological mechanisms governing microbial ecosystems in such an extreme oceanic environment.

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Microbial ecosystems and ecological driving forces in the deepest ocean sediments

This issue of Cell includes three research articles and a Commentary piece on the hadal ocean research; two of the research articles are open access, including this paper on microbial evolution.

Image credit: graphical abstract from Xiao et al. linked above (CC-BY)

Note: this is mostly a repost of a Snippet I wrote for our company, with some additional links.

[AllenWitmerMiller (Semi-Expired Professor & Minister.)]

Even so, it seems like they’ve been to hell and back.

I heard that Trump was told about conditions in the hadal zone and he promised to bring hotels and office buildings “like nobody has ever seen.” (It fits with his promises to make everything great again. Or bring hell on earth. Or whatever. You get the idea.)

I had recently asked my A.I. subscription engine about the state of DNA analysis on hadal zone microorganisms—and I was blown away by the sheer mass of data from countless specimens already gathered. Never thought I’d see anything like this in my lifetime. (And I can’t even begin to understand how biological metabolic systems operate in such a hostile environment. It’s somewhat like trying to imagine survival on another planet.)

I wonder if “creation scientists” have published much on how the Great Flood impacted hadal diversity and biozones. (And before the Fall, would a “perfect” earth have such a hellish place of hadal creatures? Or were they created after the fall as a feature of a “fallen and corrupted” world? Inquiring YECs want to know.)