Indexing the archive…
Your Universe of Digital Possibilities
Use a part and it strengthens; leave it idle and it withers — and the gain passes to the young. Lamarck’s engine of adaptation, run on a breeding bench: watch it climb. Then dock the tails, breed, dock again, and count.
Lamarck’s engine, made quantitative: the young inherit a share h of what their parents acquired, Δ. Under a standing use the trait climbs every generation with no selection at all.
The germ line is set apart from the body: nothing acquired in a life (Δ) writes to what is passed on. Dock tails for five generations and every pup is born whole.
Lamarck named a real problem and built the wrong engine for it. Use-inheritance is coherent and testable, and on the bench it produces directional, heritable change; one clean experiment refuted it — Weismann’s tails, counted across generations, the germ-plasm barrier standing. The problem was real and later solved: The Strain runs Darwin’s selection, the engine that works without use. In the edition, The Ash is the other theory whose bookkeeping outlived its arrow.