By Jeff Gordinier
Updated September 09, 1994 at 04:00 AM EDT

Over the past 16 years or so, the Dude — a slackjawed, headbanging hybrid of surfer, Valley Guy, and hemp-addled cretin — has secured a permanent toilet seat in the pantheon of American pop culture. Call it reverse evolution, and take a brief look at how it happened:

*Cheech and Chong (Up in Smoke, 1978) Although not exactly Dudes, these dynamic dopers share two crucial traits with their offspring: aimlessness and an inability to form complete sentences.

*Jeff Spicoli (Fast Times at Ridgemont High, 1982) The Ur-Dude. When zonked Spicoli (Sean Penn) has a pizza delivered to class in Fast Times, America witnesses the dawning of a new age.

*J Mascis (Dinosaur, 1985) The debut platter of his band, now called Dinosaur Jr, unveils the Dude Rocker—a blank-faced wuss with a tortured soul. *Bill and Ted (Bill & Ted’s Excellent Adventure, 1989) Two Dudes (Keanu Reeves and Alex Winter) take air guitar and the vowel-heavy Southern California dialect mainstream.

*Wayne and Garth (Wayne’s World, 1992) The Dudes (Mike Myers and Dana Carvey) become entrepreneurs, forcing even The New York Times to use ”Way” in a headline.

*Pauly Shore (MTV’s Totally Pauly, 1990) The Dude as weasel, on the eternal search for a tasty babe. Takes the lexicon of Dude-speak to a whole new level.

*Beavis and Butt-head (MTV’s Beavis and Butt-head, 1993) The Dude discovers his inner child. *Floyd (True Romance, 1993) The Dude (Brad Pitt) at his most inert-when Mafia goons hold him at gunpoint, he’s too stoned to blink.

*David ”Puck” Rainey (MTV’s The Real World, 1994) The Dude at his most disgusting (snot rockets, zero personal hygiene). Proof that the species is not a fictional construct.