JAMES HUTTON: Another key advance was the publication in 1785 of a book, Theory of the Earth, by the Scottish geologist James Hutton (1726-1797) in which he showed that the earth in fact has had a long history - as he put it, "we find no vestige of a beginning, no prospect of an end." By the time the 19th century opened, science was finally in a position to understand dinosaurs for what they are.

There is another facet of Hutton's writings that is marvelously intriguing and pointedly illustrates how the development of even the most fundamental concepts in science sometimes hinge on vagaries in timing and opportunity. At the time of his death, Hutton had nearly completed a book entitled Principles of Agriculture, the manuscript of which was, in essence, lost until 1947. In this book, Hutton writes: "To see this beautiful system of animal life (which is also applicable to vegetables) we are to consider, that in the infinite variation of the breed that form best adapted to the exercise of those instinctive arts, by which the species is to live, will be the most certainly continued in the propogation of this animal, and will be always tending more and more to perfect itself by the natural variation which is continually taking place. Thus, for example where dogs are to live by the swiftness of their feet and the sharpness of their sight, the form best adapted to that end will be the most certain of remaining, while those forms that are least adapted to this manner of chase will be the first to perish; and the same will hold good with regard to all other forms and faculties of the species, by which the instinctive arts of procuring its means of substance may be pursued." There, from the pen of a man who died 11 years before Charles Darwin was born, is the idea of Natural Selection. Had Hutton's book seen the light of day when it was written, rather than a century and a half later, it is he who might now be the icon of evolutionary biology - and the nemesis of creationists and other literal interpreters of religious tracts. And Darwin might be an obscure geologist/biologist, known primarily for his papers on the geology of the Andes, and for his treatises on orchids and earthworms. This is perhaps the greatest "if only" in the history of biology and geology.