Game theorist Jesper Juul has just posted an article from a forthcoming academic journal, named 'Swap Adjacent Gems to Make Sets of Three: A History of Matching Tile Games', and it does a creditable job of summing up the influences and path of the 'match three' genre.

This actually extends the project from an earlier GSW-linked diagram by Juul attempting to chart the genre, and it's noted of how it might have started: " From the top of the diagram [.PDF link], there are two progenitors of matching tile games, Chain Shot (figure 4, Moribe, 1985) (also known as Same Game) and the better known Tetris (figure 5, Pajitnov and Gerasimov, 1985). We cannot rule out the existence of earlier little known matching tile video games, but we know that Tetris was an extremely successful game that spawned a number of imitators, and we can see the influence of Chain Shot at various points in the tree. Both of these games were originally non-commercial."

The subject of casual game cloning is also dealt with in a section called: 'Zuma: The controversy of moderate innovation', explaining quite correctly: "Even more than other distribution channels, the casual game channel is characterized by the two opposing requirements of familiarity to the player and an element of innovation to differentiate a game from other games on the market. This creates a somewhat schizophrenic environment of cutthroat competition between developers simultaneously trying to out-innovate and out-clone each other." And yes, the whole Puzzloop, Zuma, and Luxor thing is then discussed, for kicks.