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Works in Progress ·For the curious

The Upper Limits of Biology

by Works in Progress

Published 2026-08-06 14:10:29+00:00

After 4,000 years of breeding horses for speed, what happens when they simply can't get any faster?

0:00 / 26:41 · Narrator Vindemiatrix

Context

For centuries, breeders have treated the racehorse as an engineering problem to be solved with pedigree charts and stopwatches. But an essay published on 6 August 2026 in Works in Progress pauses on a different question: what happens when an animal actually hits its biological ceiling? The pursuit of the ultimate thoroughbred has produced incredibly fast runners, but it has also backed the species into a genetic corner. The story is ultimately about the hard physical limits of human ambition.

Show notes

A biological history of the horse, tracing its development from a small forest dweller to the modern thoroughbred. Fossil records and recent DNA sequencing show how centuries of selective breeding for speed and temperament severely narrowed the animal's gene pool. This loss of genetic variety explains why racehorses have likely hit a hard physical limit, preventing them from running any faster than they did fifty years ago.

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