The Heike Crab and Artificial Selection

The Crab with the Samurai Face


On April 24, 1185, the seven-year old Japanese Emperor Antoku and his Heike Samurai were killed in a mighty naval battle around Danno-ura in the Japanese Inland Sea by the Genji Samurai. Legend has it that the Heike Samurai still walk the bottom of the Inland Sea...

Carl Sagan's Heike Crab Artificial Selection Process


  1. Crab with markings slightly resembling face is caught but returned to sea
  2. Crabs with markings not resembling face are eaten
  3. Over time, more crabs with markings resembling face survive than others
  4. Crabs with face-markings mate and reproduce creating off-spring with face-markings
  5. Eventually, the markings become more pronounced and resemble a scowling samurai

From Carl Sagan's Cosmos

Why shouldn't we believe this?


  • Heike Crabs are too small to eat (only 30 mm) and are thrown back regardless of appearance
  • Carl Sagan was on drugs
  • Carl Sagan also envisioned creatures called Floaters the size of cities floating in the convection zone of Jupiter
  • It is the human mind that creates the face of a samurai, not evolution

You decide...

The Japanese Inland Sea
Only 43 Heike Women survived the
battle. By the fisherfolk, the
Heike line continued and still
goes on today. Every April 24
the fisherfolk throw a festival
in remembrance of the Heike that
died at the Battle of Danno-ura.

Links


YouTube - Cosmos: Heike Crabs
Books by Carl Sagan
Would you believe this man?
Carl Sagan lived from 1934 to 1996 and is still regarded as one of the greatest astronomers of the century. He is famous for saying "we are starstuff" and for calling Earth a "pale blue dot." He has promoted the idea of exobiology and the search for extra-terrestrial life. As well as his many acclaimed books, he has worked on a television series called Cosmos and the movie Contact starring Jodie Foster was based on his book of the same name.