The shells of crabs found around a particular coastal location in Japan seem
mostly to resemble the legendary face of a Samurai. Given below are two
explanations of this observed fact. Which of these strikes you as a scientific
explanation ?
(a) A tragic sea accident several centuries ago drowned a young Samurai. As a
tribute to his bravery, nature through its inscrutable ways immortalised his
face by imprinting it on the crab shells in that area.
(b) After the sea tragedy, fishermen in that area, in a gesture of honour to
their dead hero, let free any crab shell caught by them which accidentally had
a shape resembling the face of a Samurai. Consequently, the particular shape
of the crab shell survived longer and therefore in course of time the shape
was genetically propagated. This is an example of evolution by artificial
selection. [Note: This interesting illustration taken from Carl Sagan's 'The
Cosmos' highlights the fact that often strange and inexplicable facts which on
the first sight appear 'supernatural' actually turn out to have simple
scientific explanations. Try to think out other examples of this kind].