This is an excellent study and historical view (plus a good read) on one author's take on the history of Funk;
THE HISTORY OF FUNK BY RICKEY VINCENT at the Amoeblog
Rickey Vincent literally wrote the book on funk. The college professor, writer, and radio DJ, who resides in Berkeley CA with his wife and two sons, is the author of the acclaimed music history book Funk: The Music, the People, and the Rhythm of The One (St. Martin's Press) which won the ASCAP Deems Taylor Award. If you don't already have this book, with a forward by George Clinton, I highly recommended it since it is the most comprehensive study on funk.
In addition to being an author & journalist, Vincent has taught at City College of San Francisco and SF State University where he taught a course entitled Protest Music Since 1965: Funk, Rap and the Black Revolution. Rickey is also a longtime Bay Area radio DJ at stations KALX and KPFA, where he still hosts his popular weekly funk show The History of Funk, Fridays at 10PM on 94.1FM.