The first fish to take a step toward bicycling was Tiktaalik. This now extinct Devonian critter is understood by scientists to represent a transitional form between fish (water dwelling finned animals) and tetrapods (land dwelling legged animals). Before Tiktaalik came to light, scientists had a pretty good idea of both when and where a transitional form must have lived, because they had an extensive fossil record of both early tetrapods and what had to have been their fish ancestors, and thus they had a very good idea of the age during which the transition must have taken place. They also had a hypothesis about what type of environment such an animal must have lived in. But back in the 1900’s, no one had yet put their hands on a fossil of such an animal. In the year 2000 a group of scientists decided to go looking for it.
Science proves both its validity and its power by its ability to predict. If astronomers tell you there will be an eclipse on a certain day in a certain place, and it happens right on schedule, you can be assured that these people know a great deal, though not everything of course, about what they are claiming to know. You can safely assume that the theory that they are using as an explanation of the phenomena they study has a lot of validity. This power of prediction is one way to distinguish, when addressing some politico-ideo-religio touchy subject, between the empty bloviating of the talk show host, the emotionally clouded, fist-shaking shouting of the rabid ideologue, and the calm focus on facts, the rigorously defined claims, and structured hypotheses of a scientist. Though humans don’t seem to have it totally figured out quite yet, if you can trust anyone to give you the straight truth, you can trust scientists. When I say this, I mean scientists as a group, because it is as a group that they challenge and check each other, and as a group that they gain the widest perspective, most intensive cross-checking, greatest intellectual depth and highest credibility.
A team lead by Neil Shubin of the University of Chicago, Dr Edward Daeschler of Drexel University, and the late Dr Farish A. Jenkins, Jr., of Harvard University, decided to go after this transitional form. They determined that they would look for 375 million year old rocks that were also representative of a type of sediment that would be deposited in a shallow water environment. They scanned the vast catalog of worldwide geologic data that has been built up and mapped over the last two hundred years. They eventually found deposits with these two characteristics on the geologic map of Arctic Canada. They financed a plan to go there and look for traces of the animal they knew must be there, if it was to be found anywhere. Waiting till the Arctic summer melted at least some of the snow, they flew to Ellesmere Island. It took four of those brief arctic summers, but they searched and dug until they found what they were looking for.

In 2004, three fossilized Tiktaalik skeletons were discovered in rock formed from late Devonian river sediments on Ellesmere Island. At the time of the species’ existence, Ellesmere had been, according to scientific consensus, part of the continent Laurentia, which was centered on the equator and had a warm climate. This new creature generally had the characteristics of a lobe-finned fish, but with front fins featuring arm-like skeletal structures more akin to a crocodilian, including shoulder, elbow and wrist. It had sharp teeth of a predator fish, and its neck could move independently of its body, which is not common in other fish. Tiktaalik can be compared to the modern gar fish, with which it shares a number of characteristics. The fossils discovered in 2004 did not include rear fins and tail, which would be found several years later. Those rear appendages turned out to have similarities to those of the African Lungfish, which can support and propel its body by walking when its weight is partially suspended in water.
Accurately predicting the general nature of this transitional species, predicting the environment in which it must have lived, predicting the type of rocks in which fossils of it might be found, and predicting the location of those rocks hundreds of millions of years after Tiktaalik’s existence; all of these successes together represent a triumph of the scientific method. Science demands rigor, it demands honesty and openness to peer review, it demands evidence, it demands testing and replicable experimentation. The scientific method of hypothesizing, testing, widely reviewing and building on other rigorously won knowledge is the greatest intellectual achievement of mankind. The discovery of Tiktaalik is an outstanding example of this achievement.
Tiktaalik appears to be the first animal to have legs, and therefore would be the first animal that could have had any chance at all of propelling a bicycle. As the proposed possible ancestor of tetrapods, any animal that has ever ridden a bicycle–bears, squirrels, parrots, monkeys, apes, humans–would be its descendant. This being so, every woman that has ever yearned to throw a leg over a velocipede would be therefore, at their deepest and most primitive core, a fish that needs a bicycle.