Albinism

Robert Taylor via Flickr

It all started with a black squirrel.  These rare creatures aren't a separate species - they're your garden variety gray squirrel, but a genetic mutation has given them a black fur coat.  That got Dave wondering if a black squirrel has any advantages its fairer forebears don't (other than being incredibly popular among nature photographers).  Wondering turned to arguing.  

Robert Taylor via Flickr

It all started with a black squirrel.  These rare creatures aren't a separate species - they're your garden variety gray squirrel, but a genetic mutation has given them a black fur coat.  That got Dave wondering if a black squirrel has any advantages its fairer forebears don't (other than being incredibly popular among nature photographers).  Wondering turned to arguing.  

Robert Taylor via Flickr

It all started with a black squirrel.  These rare creatures aren't a separate species - they're your garden variety gray squirrel, but a genetic mutation has given them a black fur coat.  That got Dave wondering if a black squirrel has any advantages its fairer forebears don't (other than being incredibly popular among nature photographers).  Wondering turned to arguing.