Darwin’s theory of evolution provides an explanation of how species change biologically through the forces of natural selection. Culture also changes, as new ideas about art, commerce, technology, etc. are created, accepted, and passed on in society. This concept of culture change can be applied to almost anything we experience in daily life, including the creative form of communication known as bathroom graffiti.

Ever since Grog scrawled, "My club is bigger than Zogg’s," in a cave somewhere thousands of years ago, people have been leaving messages for each other in the bathroom. These messages can be classified into a typology represented by two major categories, Passive Bathroom Graffiti and Active Bathroom Graffiti. With Passive Bathroom Graffiti there is no call to action, the writer is simply stating a fact or an opinion or relating a personal experience. Basic examples include: "Angie sux dix," "Sigma Chi Rules," (followed by "Sigma Chi rules the fudge packing plant"),"Dokken are a bunch of fags," "Billie is a vomit whore," as well as assorted limericks and various forms of iambic pentameter.

Active Bathroom Graffiti includes a specific call to action urging the reader to place a telephone call, make a social visit to a local sorority, or perhaps to copulate with him or her self. Classic examples of Active Bathroom Graffiti include infinite variations of "For a good time, call 555-0386," or "For a blow job call 555-0386." However, it has recently been noted that new forms of technology, specifically the Internet, are being represented in Active Bathroom Graffiti messages. Initially, bathroom graffiti artists borrowed the lexicon of 1-800 numbers, with examples such as "For a good time call 1-800-HOT-FUCK (468-3825)," and "1-800-EAT-MUFF (328-6833)." As the World Wide Web and e-mail became commonplace in American society, Active Bathroom Graffiti messages began using the Internet in their call to action with examples such as "E-mail Sandra at LooseTwat@aol.com," "Todd bookmarks www.mikelikestocatch.com," and the groundbreaking "For a good time, e-mail SUZIE@ohmygod/Im/about/tohave/an.org."

Passive Bathroom Graffiti has also evolved, with high technology becoming the content and subject matter of these stinky salutations. Examples include "Why can't Bill Gates get a date? Because he is MICROSOFT," "Your mother is so fat, it takes 25 minutes to download a naked picture of her," and the instructional "BASIC PROGRAM:

The porn industry has always been on the leading edge of technology, with the use of film, video and the Internet, and so it’s no surprise that the next stage of evolution in bathroom graffiti follows a similar path. Although one could argue that bathroom graffiti is at the end of the socio-techno evolutionary curve of which the porn industry was the vanguard. We can only speculate about what new forms bathroom graffiti may take in the future, from the use of wireless networks that allow you to receive cell phone text messages when entering a bathroom to pop up limericks on urinal flat screens. The possibilities are endless.