ScienceDaily for January 11, 2011 reported on similarities between fish and mammals.
Elephant fish, a relative of sharks, utilize the same genetic process for forming skeletal gill covers that lizards and mammals use to form fingers and toes, researchers at the University of Chicago and the University of Cambridge found. The precise timing of when and where that gene is expressed during embryonic development produces dramatic anatomical differences between elephant fish and their close relatives, the dogfish.
