In social philosophy, "every man is my brother" is a quotation often used to suggest we should treat everyone as if they were indeed our siblings. This concept expanded almost without bounds when the implications of evolution became understood. Not only did every man became our brother, but also the whale, the fruit fly, and the oak tree. Well, not exactly our brothers, but nevertheless our relatives—and literally rather than figuratively!
Of course, not all organisms share an equally close relationship. As
you wander through our desert, a glimpse of a coyote or rabbit is a sighting of a close
relative who shares the inheritance of hair and suckling of young. A scurrying lizard
is more distant, but we've inherited four limbs and a backbone from our common
ancestor. And that mesquite bush that the lizard ran into? Another, oh so distant,
relative. What do we have in common, you ask? Well, for one thing, the coding of our
genetic material—a code handed down from a time even before our ancestors crawled from
the sea.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
A distant relative: Prickly Pear cactus, Chihuahuan Desert Gardens. Photograph by A.H. Harris.