A new theory “emerges first in the mind of one or a few individuals” but then it spreads because the field faces “crisis-provoking problems.”
Hippocrates proposed in the late 5th or early 4th century BC a model for heredity and adaptation that Charles Darwin described as nearly identical to his own.
“Many life forms with essentially new body types appeared quickly and without precursors in the Burgess Shale in Kicking Horse Valley in British Columbia.”
They conclude, “there is something besides mutations and survival of the fittest needed to explain evolution.”
If you’ve ever owned an automobile toward the end of its life, the situation will be familiar.