Eozoön Canadense "The Dawn Animal of Canada"

Abstract

17OZOON CANADENSE, dawn animal of Canada, was found in the PreLcambrian rocks of eastern Canada in 1858. The discovery startled the geological world, since at the time few paleontologists believed that such metamorphic rocks could preserve fossils or even that life could have existed so long ago. In fact, what we now call Precambrian was then commonly designated by the term Azoic-lifeless. It is not surprising, then, that the authenticity of Eozoon canadense was disputed. The ensuing controversy lasted for nearly fifty years and developed into of the most contentious issues in nineteenth-century geology. While the inorganic nature of Eozoon has long been established and Eozoon is no longer of scientific interest, the controversy has significance for the history of science. It provides an example of the manner in which every aspect of nineteenth-century paleontology was scrutinized for its bearing on evolution. It is also a classic case of the confrontation of younger specialists with each other and with the older generation of broadly trained naturalists. There were two chief reasons for the persistence of the dispute. Most obvious and most important was the inability of early paleontology to settle the matter. The second reason, seldom stated by the disputants, was the significance of Eozodn in the larger issue of derivation of species. For, were Eozoon proved to be organic, evolutionists would be confronted with the most impressive of all gaps in the paleontological record, a gap that would give pause to even the most ardent evolutionist. the other hand, if this gap were successfully explained or overcome by the finding of subsequent forms related to Eozoon, the evolutionists could rejoice in having found, at the earliest date of known animal life, the simplest of life, a reasonably akin to the one primordial form of Darwin's speculation.' In short, there was something at stake for both sides in the greater scientific controversy. Darwin himself was interested in Eozoon and its promise for his position. He introduced Eozoon into the fourth edition of The Origin of Species: After reading Dr. Carpenter's description of this remarkable fossil, it is impossible to feel any doubt regarding its organic nature.'2 Darwin cited Eozoon in his famous tenth chapter, On