Priority Issues
William Chauncey Hooker (1894) patented a flat snap trap: “for catching mice and rats, a simple, inexpensive and efficient trap adapted not to excite the suspicion of an animal, and capable of being arranged close to a rat-hole.” It allowed for mass production and went through many modifications (Drummond et al. 2002).
A safe-to-set modification of Hooker’s design was invented by John Mast (filed 1899, patented 1903): “The object of the invention is to provide means whereby traps of this class [flat snap traps] may be readily set or adjusted with absolute safety to the person attending thereto, avoiding the liability of having his fingers caught or injured by the striker when it is prematurely or accidentally freed or released.” The fact that Hooker sold his Animal Trap Company of Abingdon, IL, and it merged with the J. M. Mast Manufacturing Company of Lititz, PA, in 1905 (Drummond et al. 2002), may have contributed to a false attribution of priority to Mast (Hope 1996). Unfortunately, the misbelief in Mast’s priority is transmitted (e.g., Shanks and Joplin 2000).
Others falsely credit priority to James Henry Atkinson of Leeds, UK (e.g., Bellis 2009). His “Little Nipper” received GB patent no. 27,488 in 1899 and has a treadle cut out of the whole width of the base. This increases the likelihood that the trap is sprung when a mouse only passes over it without being attracted to the bait. Another urban legend has Hiram Maxim, inventor of the machine gun, as inventor of the first flat snap mouse trap (e.g., “Mousetrap” by Wikipedia contributours, version before January 6, 2010). In his memoirs, however, Maxim (1915) described his inventions as automatic cage traps. The resetting automatism of one was powered by a coiled spring made from the hoop of a skirt, and that of the other was powered by the entering mice themselves.
One Part Less: The Seminal Precursor
The first mouse trap based on Hooker’s patent was called “Out O’ Sight” (Fig. 1) and produced in 1894 by the Animal Trap Company in Abingdon, IL.
This original design had the spring and striker formed of one wire. Current flat snap traps have separate spring and striker because their production and assembly is easier that way. This particular modification has not been patent-worthy, however, because other kinds of mouse traps (not flat) with separate spring and striker existed before.
The common ancestor of all current flat snap traps had one part less, and the great variety of these traps today is due to its success. Therefore, Behe’s first conclusion is wrong. Irreducibly complex systems can have working precursors with one part less.
Similar variations in the number of parts occurred throughout mouse trap history. Irreducible complexity is no obstacle to varying numbers of parts by addition, fusion, or separation of parts. The only thing that does not work is taking away a part that carries a function.
Continuous History: The Straight Story
The ancient Egyptian culture was highly pictorial, and trapping fowl was a royal sport. Catching rodents was no royal sport. Nevertheless, rat cage traps made of pottery are also known from ancient Egypt (e.g., Drummond et al. 1990) and elsewhere. Therefore, the fact that the oldest historical records are bird traps from Egypt cannot be taken to mean that these traps were confined to Egypt or to catching birds.
Twisted fibers powered nets, snares, or clubs with skull-crushing spikes (Lagercrantz 1950). Some ancient bird traps were strikingly similar to flat snap mouse traps (Fig. 2a, b). Grdseloff (1938a) and Scott (1940) feature restored specimens. Grdseloff (1938b) identified hieroglyphs for this trap kind and traced them back into the old kingdom (2686–2181 bce). Similar traps survived into recent times (Fig. 2c).
Later versions were entirely of wire. Such spring-loaded wire traps are still used for birds in the Mediterranean region. They were also promoted as rodent traps in the nineteenth century. Ets Julien Aurouze, Paris, has been decorating their shop window with stuffed rats dangling from these traps ever since 1872 (see www.aurouze.fr/deratisation.html). The display has become a tourist attraction also featured in the film Ratatouille. Nevertheless, Aurouze’s online catalog lists these traps as Piège à oiseaux (trap for migrating birds).
An advert of Orlando Leggett, Ipswich, and a patent of George Frost (1891) from Toronto, Canada, explicitly call them rat traps. Similar traps were marketed as “bird and mouse traps” in Germany (Drummond and Dagg 2010). While one wire formed handle and spring in Legget’s “Cyprus” (Fig. 2d), base-jaw and handle are a unit in Frost’s patent (Fig. 2e). In none, however, were spring and striker of one wire.
Here, as elsewhere, the historical record poses the paradox that homologous ideas can be culturally transmitted via analogous structures. The historical context, however, suggests that the traditional clap-bow trap inspired the invention of such a trap entirely of wire and its wide sale in the Mediterranean (Schäfer 1918/19). That is, the idea of a flat snap trap has been culturally transmitted. Niles Eldredge (e.g., Tëmkin and Eldredge 2007) refers to the deliberate invention of alternative realizations as the “Hannah principle.” In the broad sense, the Hannah principle is an extreme case of lateral transfer, when all the parts of a trap system are exchanged at the same time. In the narrower sense, it is an exchange of material parts that requires an analogous solution. For example, the twisted cord of torsion traps was replaced by a coiled wire.
The main success (and conservation problem) of this design remains in trapping song birds today (see website of “Lega Italiana Protezione Ucelli”). Maybe birds are particularly unsuspecting against bait sitting on a twig-like wire structure. Its use as a bird trap may also explain why this design has hardly been recognized as belonging in the history of mouse traps. Mounting striker, spring, and set/release mechanism on a wooden base, however, yields a traditional tinker mouse trap (Fig. 2f, g).
In the nineteenth century, tinkers peddled their goods around the world (Drummond and Dagg 2010). Slovakian tinkers (Drotári) even reached America during tours of up to eight years (Ginzler, unpublished).Footnote 1 From 1870 onwards, an increasing number of Slovaks immigrated into the United States for good. Coincidentally, their favorite destinations were the Northeast and Midwest including Pennsylvania and Illinois.
The tinker trap (Fig. 2f) differs from Hooker’s patent. Spring and striker are not formed of one part; the spring has an uncoiled middle part looking like the handle of a Cyprus-like trap (see Fig. 2d, e); the set/release mechanism has a bait hook, as in clap-bow and Cyprus-like bird traps, rather than a pedal.
If specifically cultural ways of information transmission are included, the descent from Bronze Age torsion traps to current flat traps shows no big jumps in design. The exchange of wood and fibers for wire necessitated a change from twisted to coiled power source exemplifying the Hannah principle in the narrower sense. History is as continuous here as later, when tinkers exchanged the base wire-jaw for a wooden platform transforming a veritable bird trap into a veritable mouse trap.
The meta-level question of how the historical records reached us, rather than how the artifacts have been transmitted in the past, reveals reconstructing, reverse-engineering, and decoding (language) as further ways of information transmission. This list does not, by far, exhaust the means of time-travel (recovery), which cultural information has (e.g., archiving, excavation, and preservation). Dormant cultural information can jump back into use (Wimsatt 1999). Therefore, continuity of artifact history does not imply a uniformly ticking clock of cultural change.
Evolution: All Prerequisites Abound
We are not here considering the question whether mouse trap history is in fact a case of evolution, but whether it cannot be evolutionary in principle, as Behe (1996) claimed.
Variation
The Animal Trap Company, Lititz, PA produced more than 30 variant snap traps and 13 variant set/release mechanisms (Drummond et al. 2002). Other companies, countries, times, and traps show equal variability (recorded mainly by Lagercrantz 1950, 1964, 1966, 1972, 1984, 1987) and Drummond (2004a, 2005, 2006, 2007, 2008, 2009a, b). For example, Drummond (2005) features over 60 variants of British flat snap mouse traps.
Transmission
The “Out O’ Sight” retained an old design of spring and striker being made of one wire (see Fig. 1). Similar instances of transmission could be provided for other trap kinds. Cyprus-like traps retained the bait hook of ancient torsion and traditional clap-bow traps. Lateral transfers are, of course, also instances of transmission though they cross the categories that users perceive as different kinds of artifacts.
Selection
For example, the torsion power source using twisted fiber was replaced by wire springs. Mascall’s record of 1590 shows that Renaissance torsion traps (Fig. 4) existed alongside traps using an uncoiled wire spring (Fig 5a). Torsion power even survived up to the late nineteenth century in Egyptian clap-bow traps (Fig. 2c; Schäfer 1918/19) before the coiled wire spring replaced it. Nowadays, the torsion power source seems to be utterly extinct excepting the possibility of relics in some remote regions.
Differential reproduction can be expressed as the ratio of patents filed to patents used. Unfortunately, inventors do not tend to specify patents further than “animal trap,” in order to keep their options open. Drummond (2004b)Footnote 2 identified 4,593 US patents suitable for mouse traps in principle, from which 165 have been used in 149 actually manufactured mouse traps. The commercially successful traps, however, used only seven patents. Hence, 4% of the patents filed were used, and 5% of the patents used were commercially successful. These figures compare quite well with an estimate in 1869 by US Commissioner of Patents Samuel S. Sparks that 10% of all patents (not just mouse traps) had some commercial value (Basalla 1988).
Selection among mouse trap patents may be stiffer than among patents in general due to a popular quotation attributed to one of Ralph Waldo Emerson’s spring 1871 lectures (Adams 1947): “If a man can write a better book, preach a better sermon, or make a better mouse trap, than his neighbor, though he builds his house in the woods, the world will make a beaten path to his door.” Many a mouse trap inventor has been crestfallen to find no such path beaten to his door.
Basalla (1988) showed that cultural values are a crucial ingredient in the success (selection) of artifacts. The name “Out O’ Sight” indicates one such value. The trap could be placed were visitors would not see it, unlike the cage traps, chokers, and dead-fall traps dominating the scene before (Hornell 1940; Hellwig, unpublishedFootnote 3). When mass production took off, its cheapness also allowed to discard the trap along with the dead body, probably a high cultural value to urban dwellers. All earlier trap types required a handling of mice and often a thorough cleaning of the trap for repeated use. As caged mice were usually drowned or starved to death, these traps were less humane than may appear at first sight. Another modern cultural value is the upper surface of flat snap traps as space for advertisement (see Fig. 1a; Drummond et al. 2002).
Interestingly, these cultural values do not concern the trapping function. On the one hand, a flat surface that can be used for advertising is a spandrel (Gould and Lewontin 1979; Sole, this issue). On the other hand, advertisements affect consumer selection, and the availability of such surfaces affects vendor selection.