"In a startling exception to classical genetics, mice in a lab experiment have inherited an effect of an aberrant gene without inheriting the gene itself."

http://news.yahoo.com/s/ap/20060526/ap_on_sc/gene_free_traits;_ylt=AhPmzj6z7byi1UNzJwje5b1xieAA;_ylu=X3oDMTA3MzV0MTdmBHNlYwM3NTM-

This study would suggest that RNA can be the stuff of inheritance as well as DNA. Who knows what plasmids lurk in the genome of mankind?