Particularly amusing, was the comment that one of the primary defence mechanisms of the armadillo is to jump into the air. It would appear that Mother Nature did not allow for cars when planning her evolutionary path for the armadillo, since jumping into the air tends to send the unfortunate creature crashing into the radiator grill. Other penises were also studied, including the white tailed deer, the maned wolf and the African elephant.

I have had the pleasure of going to Florida several times and while I will admit that the selection of roadkill is more impressive and varied than that in Britain, I failed to spot a maned wolf or African elephant lying at the side of the road.

This of course poses the question of where did these specimens come from. The author of the Armadillo paper, Dr Diane A. Kelly, tells me that unsurprisingly she has friends in zoos. I am sure that if you asked the average person what species of animals are used in research, most would answer with rats, mice and the proverbial guinea pig. How many would come up with white tailed deer?. Other than reading every single piece of published work, a quick look through the catalogue of a tissue culture repository such as ECACC (European Collection of Cell Cultures), would indicate the variety of animals used in research.

Many researchers work on cultured cells that are grown in an incubator, without ever having to go near the actual animal, thereby reducing both the numbers of animals that are used in research and the possibility of being bitten. After browsing the ECACC catalogue, it became apparent that Noah must have been instructed to collect breeding pairs of every species, not to save them from the floods, but to provide sufficient samples for scientists of the future.

The cells derived from the potoroo must surely offer advantages to cell biology that other cells cannot? I must admit that I was more than a little disappointed to find that it is a small kangaroo rat. Assuming that the potoroo is unique experimentally (i.e. has a unique biological property that no other more common animal can provide), can it be assumed that the same goes for the Gilthead seabream, saltmarsh caterpillar, eel, boar, black bear, dolphin or Russels viper not to mention any of the other species listed. According to Dr Kelly, the penis study needed to use animals that met strict requirements such as the size of the animal (and its penis) as well as certain anatomical criteria. These requirements ruled out the use of slaughterhouse animals and rodents etc, leaving the armadillo, which met all of the requirements and is apparently very common roadkill in the 50-mile circuit that Dr Kelly drove every day.

Researchers in the field of cell biology are familiar with a variety of animal models that are routinely used, that the non-scientist may think of as being
bizarre. This is probably not helped by the fact that they are commonly referred to by their Latin names. The fruit fly (Drosophila melanogaster), nematode worm (Caenorhabditis elegans) and South African clawed toad (Xenopus laevis) are frequently used in studies of cell biology, development and genetics.

To researchers, the benefits of these organisms are obvious although non-scientists may feel they are as obscure as the potoroo. What many people will not realise though is that the numbers of biological processes and even proteins within these organisms and others, including yeast, are remarkably similar to those in humans. This can be taken to the extreme, when proteins from these organisms can be put into human cells and function in a normal way.

In 1999, a MORI poll conducted with New Scientist found that the views of many people regarding animal research change depending on the species involved. The use of rats and mice, which most people consider vermin, appears to be more acceptable to the public than the use of other animals such as monkeys. On the scale between rats and monkeys, where do Noah's other passengers fall? Next time you contemplate the use of animals in research, remember the poor old armadillo.