[gumby]

Tremens answered about Häckel; the Möbius strip part is Piaget’s model of learning which says that knowledge undergoes continuous rewriting rather than being simply accretive, a view which I would think should be unremarkable today.

Häckel came from a 19th century conception of “advancement” or “progres” — think of that absurd 19th century picture of various apes followed by a human, as if a human is somehow the “most evolved” of the animals. The idea of adaptation to the environment was alien (and apparently frightening) to most people in the West.