Plotkin, Henry. 1994. Darwin Machines and the Nature of Knowledge. Cambridge, MA: Harvard University Press.

Plotkin effectively points out that evolution is a form of induction. (A point already made by Pringle, in 1951. *)

Evolution as Falsification

Notice the similarity between biological evolution and Popper's Falsificationist philosophy. Recall that Popper argued that the progress of knowledge arises by a series of conjectures and refutations. Each refutation trims the tree of possible theories. Evolution by natural selection appears to be an analogous process. An individual within a species is a sort of hypothesis about the structure of the environment. If the individual fails to procreate, fails to survive, then nature has "falsified" the hypothesis. Conversely, the individuals that survive and procreate are hypotheses that "failed to be falsified" by the environment.

Evolution and the Duhem-Quine Thesis

Recall also the Duhem-Quine criticism of falsification. They noted that the problem with a falsifing observation is that the experimenter does not know what precisely is falsified. Perhaps the observation itself is incorrect. The instrumentation may be faulty. The observation methodology may be inappropriate. Of course, the hypothesis may be wrong. Or the hypothesis may be correct, but the overarching theoretical framework is mistaken.

A similar problem can be identified in evolution by natural selection. When an individual animal fails to procreate, there is no overt knowledge of what went wrong. Perhaps the animal was near-sighted, perhaps it had a hearing deficit, perhaps it was excessively asocial (and didn't take advantage of the protective value of other members of its species), or perhaps it was too social and spent too much time interacting with other animals rather than fending for itself. Or perhaps it wasn't interested in sex.

In short, evolution has no "knowledge" of which genes are at fault. When an individual is "falsified" it is the aggregate group of genes that is discarded. The environment selects individual animals, not individual genes. However, given enough combinations of hypotheses (enough individuals), then the overall effect of evolution appears to be one of selecting for particular genes.

Knowledge Without Truth

Finally, notice that evolution does not arrive at "the truth". Animals are more or less adapted to their environments, but there is never a perfect fit between the environment and the animal.

Also notice that evolutionary "truth" is local. We have "truth within an eco-niche". The animal has no perfect knowledge of its environment.

According to Popper, the point of a scientific enterprise is to approach the truth through conjectures and refutations. The key is not that truth is discovered, but that knowledge grows.