Electric ESP
Electrosensory powers, that is!
Sharks are known for their almost uncanny ability to detect electrical signals while hunting and navigating. Now researchers have traced the origin of those electrosensory powers to the same type of embryonic cells that gives rise to many head and facial features in humans.
The discovery, reported by University of Florida scientists in the current edition of Evolution and Development, identifies neural crest cells, which are common in vertebrate development, as a source of sharks’ electrical ESP.
“If you think of this in the big picture of evolution of sensory systems, such as olfaction, hearing, vision and touch, this shows sharks took a pre-existing genetic program and used it to build yet another type of sensory system,” [Martin] Cohn said.
All primitive animals with backbones could sense electricity, according to Michael Coates, an associate professor of organismal biology and anatomy at the University of Chicago. Mammals, reptiles and birds lost the sense over time, as did most fish alive today.
But in sharks and a few other species, such as sturgeons and lampreys, electrosensory capability endured.
Understanding evolution is so much more interesting than the rationales people invent to hide from it.
Posted: Wed - February 22, 2006 at 09:02 AM