Why is the liver so weirdly regenerative?
An essay on the liver’s unusual ability to regenerate prompts wide-ranging reactions, from enthusiasm for its accessible, speculative style to sharp criticism of its scientific depth and teleological framing of evolution. Commenters delve into why some tissues (like liver and skin) repair so well while others (like brain and heart) largely do not, touching on cancer risk, organ complexity, evolutionary trade-offs, and misconceptions about aging, diabetes, and neurogenesis. The thread also branches into cultural references (Prometheus’ liver), the realities of transplantation and immune rejection, and the broader tension between pop-science curiosity and scientific rigor on tech-focused forums.
Role of speculation and article quality
- Some commenters dismiss the piece as shallow, speculative, and framed by quasi‑religious “design” language.
- Others defend speculative, meandering pop‑science as valuable for curiosity, even if not rigorously sourced.
- Several object to teleological phrasing (“evolution decided…”, “what evolution wants”), arguing it misleads people about how evolution actually works.
Evolution, teleology, and “design”
- Repeated emphasis that evolution optimizes gene propagation, not health, happiness, or perfect bodies.
- Debate over the level at which selection acts: genes vs individuals vs populations vs multiple levels at once.
- Some argue many “bad designs” (aging, limited regeneration) persist because they don’t significantly reduce reproductive fitness.
Regeneration, cancer, and organ differences
- Liver: described as relatively homogeneous “battery pack” tissue, making regrowth easier than in highly structured organs like kidneys.
- Commenters note liver regeneration isn’t perfect; regrown tissue and vasculature can differ from original.
- Discussion that strong regenerative capacity likely increases cancer risk; evolution trades off repair vs tumor suppression.
- Clarifications that some adult neurogenesis and cardiac cell turnover exist, though at low rates. Claims that “neurons never divide” are called outdated.
- Small intestine villi turnover is highlighted as an underrated, highly regenerative system.
Aging, lifespan, and menopause
- Debate over historical longevity: high childhood mortality vs decent survival into 50–60 for those who reached age 5.
- Emphasis that modern medicine and daily “maintenance” (food, sleep, hygiene, basic drugs) are crucial to long life.
- Menopause discussed as likely tied to social structures and grandparental investment, but commenters note that “social animal ⇒ menopause” clearly doesn’t hold generally.
Immune system, transplantation, and disease
- Explanations of HLA markers and why strong self/non‑self discrimination makes organ transplantation hard but is essential against infection, parasites, and cancer.
- Liver transplant anecdote illustrates dramatic regrowth and how orientation/scarring alter organ shape; repeat live donation is said to be impractical.
- Autoimmune diseases (Type 1 diabetes, LADA, psoriasis) are mentioned; there’s confusion between T1, T2, and MODY, with some corrections from others.
Nutrition, vitamins, and fringe hypotheses
- Claims that many people are chronically “vitamin A toxic” and that low‑vitamin‑A diets help autoimmune conditions; others push back, question mechanisms, and note standard sources say plant carotenoids are usually safe.
- Additional comments link wound‑healing problems to nutrient deficiencies (e.g., sulfur/MSM), and sugar to chronic inflammation; these are presented anecdotally.
Cultural notes and resources
- Myth of Prometheus used to discuss ancient views of the liver as the seat of emotion/courage across several cultures.
- Some commenters ask for better venues for in‑depth biology discussion; a few textbooks on systems medicine and cancer biology are recommended.