Here is a diagram with a "family tree" showing the history of programming 
languages.  Ruby is in there.

http://www.levenez.com/lang/

It shows Ruby cross-polinating from Perl, Eiffel, Smalltalk, and Python.

The author also has diagrams for the history of Unix and Windows.  The 
Unix one is very impressive.  Unix is truly a diverse family.

Cheers,
-- 
Daniel Carrera | "Software is like sex.  It's better when it's free".
PhD student.   | 
Math Dept. UMD |     -- Linus Torvalds