Technology
as Motion

Organism and environment form one coupled system, and the environment is registered relative to the organism’s own size, strength, speed and senses. Material brought under control, whether grasped, supported or projected, has its degrees of freedom constrained and joins the organism’s force-transmission system. The unit that acts is then the organism together with that material, and it commands motions the body alone cannot.

The transformation this produces, Θ, is literal. A hominin holding a stick to reach fruit has, as far as selection is concerned, become larger; equivalently, the trees have become shorter. What remains after the transformation, the residual ε, is what selection goes on acting on.

While a departure stays within the capacity of the sequences held, the existing repertoire suffices and selection optimises it. When a departure exceeds capacity, the existing sequence fails and selection favours a new one. Long stretches of technological stasis are the first regime, successful buffering rather than inertia; rare bursts of innovation are crossings of the threshold.

Capacity has a direction. A sequence that buffers a shortfall in force does nothing for an equal shortfall in reach, so whether a lineage innovates depends on where a departure points, not only on its size. Robustness grows by holding sequences that point in different directions.

The anatomy that makes the realised sequence cheaper makes the alternatives dearer. When abandoning the sequence is no longer viable, the lineage is committed: robust to the perturbation the sequence meets, and fragile to its loss. Each later extension is built on those already held, and none is lost. The ratchet names that outcome. It is ordinary natural selection acting on a system whose boundary has been extended, not a second evolutionary process.

The tests are reported in the paper Technology as Boundary-Extending Motion, now in preparation. Its results will appear here once it has been submitted.