When in 1863 Thomas Huxley coined the phrase 'Man's Place in Nature,' it was to name a short collection of his essays applying to man Darwin's theory of evolution. The Origin of Species had been published only four years before, and the thesis that man was literally a part of nature, rather than an earthy vessel charged with some sublimer stuff, was so novel and so offensive to current metaphysics that it needed the most vigorous defense. Half the civilized world was rudely shocked, the other half skeptically amused.Nearly a century has passed since the Origin shattered the complacency of the Victorian world and initiated what may be called the Darwinian revolution, an upheaval of man's ideas comparable to and probably exceeding in significance the revolution that issued from Copernicus's demonstration that the earth moves around the sun. The theory of evolution was but one of many factors contributing to the destruction of the ancient beliefs; it only toppled over what had already been weakened by centuries of decay, rendered suspect by the assaults of many intellectual disciplines; but it marked the beginning of the end of the era of faith.

~ Homer W. Smith

The affinities of all the beings of the same class have sometimes been represented by a great tree.I believe this simile largely speaks the truth. The green and budding twigs may represent existing species; and those produced during former years may represent the long succession of extinct species. At each period of growth all the growing twigs have tried to branch out on all sides, and to overtop and kill the surrounding twigs and branches, in the same manner as species and groups of species have at all times overmastered other species in the great battle for life. The limbs divided into great branches, and these into lesser and lesser branches, were themselves once, when the tree was young, budding twigs; and this connection of the former and present buds by ramifying branches may well represent the classification of all extinct and living species in groups subordinate to groups. Of the many twigs which flourished when the tree was a mere bush, only two or three, now grown into great branches, yet survive and bear the other branches; so with the species which lived during long-past geological periods, very few have left living and modified descendants. From the first growth of the tree, many a limb and branch has decayed and dropped off; and these fallen branches of various sizes may represent those whole orders, families, and genera which have now no living representatives, and which are known to us only in a fossil state. As we here and there see a thin straggling branch springing from a fork low down in a tree, and which by some chance has been favoured and is still alive on its summit, so we occasionally see an animal like the Ornithorhynchus or Lepidosiren, which in some small degree connects by its affinities two large branches of life, and which has apparently been saved from fatal competition by having inhabited a protected station. As buds give rise by growth to fresh buds, and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever-branching and beautiful ramifications.

~ Charles Darwin