But by the first half of the 20th century they were increasingly threatened by competition from ever more powerful paddle steamers, something that was aided by the canalization of rivers.
If there is no canalization of a developmental pathway, genetic variation of pathway components results in a continuous spectrum of phenotypes, often distributed in a bell curve.
When the panther tries to deliver the package by flying with a rocket, the package falls into a canalization hole in street and then moves with the river down there.