'Obelisks': New class of life has been found in human digestive system

Peer Review, Replication, and Evidence

• Original work was a preprint; later appeared as a peer‑reviewed paper in Cell.
• Some argue peer review status is overemphasized; others see it as useful but limited.
• Questions about “replication” led to clarification: the finding arises from re‑analysis of large existing datasets (e.g., human microbiome projects and millions of public sequences).
• Several commenters distinguish between replication (repeat experiments) vs verification (independent analysis of the same data) and note that here the key is reproducible detection of the sequences across many datasets.

Nature of Obelisks

• Described as small, circular, rod‑like RNA elements with no detected DNA counterpart.
• Lack detectable homology to known viruses, viroids, or other agents, yet form a coherent phylogenetic group with tens of thousands of variants across datasets.
• Likely replicate via host RNA machinery, similar in spirit to viroids or other mobile genetic elements.
• Some view them as RNA “plasmids” or structured “garbage RNA”; others see them as minimal genomes and candidate selfish replicators.

Classification and “What Is Life?”

• Debate over calling them a “new class of life” vs “just another kind of virus/viroid.”
• Commenters stress that terms like life, virus, viroid, plasmid, and mobile element are fuzzy and model‑dependent.
• Discussion touches on RNA‑world ideas and the notion that all current life may be best thought of as RNA-based information systems with DNA as storage.

Health Relevance and Pathogenicity

• No current evidence linking Obelisks to human disease or even clear cellular phenotypes.
• They probably interact primarily with bacteria; any human effect would likely be indirect.
• Some speculate about possible roles in unexplained diseases or autoimmune issues, drawing analogies to past surprises like Helicobacter pylori, but this is explicitly flagged as unknown.
• Questions about “killing” them elicit the response that appropriate drugs are unknown; in principle, mechanisms targeting RNA replication or translation might affect them.

Discovery Methods and Tools

• Found by computational mining of metagenomic and microbiome datasets; not via targeted wet‑lab searches.
• Use of advanced structure and homology tools (RNA folding, protein structure prediction, LLM‑like models) was key to showing how unlike known agents they are.
• A public repository documents methods, and commenters note that data scientists and developers, not just traditional biologists, can contribute.
• RNA‑specific technologies (e.g., native RNA sequencing, RNA modification detection) are mentioned as a promising but still emerging angle.

Broader Implications and Open Questions

• Many expect more such entities (RNA and otherwise) to be discovered, highlighting how incomplete our catalog of Earth’s biodiversity is.
• Raises questions about biases in current detection and classification schemes and whether our host/virus, entity/process, and DNA/RNA dichotomies are too narrow.
• Some link this to the difficulty of detecting life on other worlds, noting that we struggle even to recognize unfamiliar biology on Earth.