What did it mean? Because the squirrels lived under very similar conditions (e.g., identical diets), it was almost surely a genetic difference. Let’s assume it was. In nature, sunlight is plenty strong. The lab light was weaker. In nature, the genetic difference wouldn’t make an observable difference. Only under artificial conditions did it become visible. It only became visible when the artificial conditions didn’t supply enough of something important (sunlight). In other words, the newly-visible genetic difference implied there was something lacking in the artificial conditions. The genetic difference implied the environment mattered. The opposite of the usual interpretation.

What did it mean? Because the squirrels lived under very similar conditions (e.g., identical diets), it was almost surely a genetic difference. Let’s assume it was. In nature, sunlight is plenty strong. The lab light was weaker. In nature, the genetic difference wouldn’t make an observable difference. Only under artificial conditions did it become visible. It only became visible when the artificial conditions didn’t supply enough of something important (sunlight). In other words, the newly-visible genetic difference implied there was something lacking in the artificial conditions. The genetic difference implied the environment mattered. The opposite of the usual interpretation.

—Seth’s blog » Blog Archive » Genes Or Environment … Or Environment?