Torch, Fall/Winter 2009

6 TORCH | Fall–Winter 2009 progenitor apply with nearly equal force to the earliest known species. For instance, I cannot doubt that all the Silurian [now called “Cambrian”] trilobites have descended from some one crustacean, which must have lived long before the Silurian age, and which probably differed greatly from any known animal ” (p. 306). Darwin is describing multiple species of trilobites appearing suddenly in the lowest Cambrian rock layers. Today, about 160 species of trilobites are known from the earliest Cambrian layers, many more than in Darwin’s day (Figure 2). None of the fossils in the rock layers below these shelled arthropods show their evolutionary origin. Darwin believed that, with time, these fossils would be found. They have not. Problem #3: Sudden appearance of multiple phyla within the same layers “If numerous species, belonging to the same genera or families, have really started into life all at once, the fact would be fatal to the theory of descent with slow modification through natural selection. For the development of a group of forms, all of which have descended from some one progenitor, must have been an extremely slow process; and the progenitors must have lived long ages before their modified descendants (p. 302) . … To the question why we do not find records of these vast primordial periods, I can give no satisfactory answer. … the difficulty of understanding the absence of vast piles of fossiliferous strata … is very great ” (p. 307). [emphasis added] Not only do multiple types of similar species appear in the earliest fossil- bearing rock layers, but multiple groups of dissimilar organisms also appear there. We can find approximately 40 different types of animal phyla alive today. These groups include the mollusks (clams, snails), echinoderms (starfish, crinoids), chordates (vertebrates), sponges, and corals. All of these have also been found within the earliest fossil-bearing Cambrian strata. A few years ago, fish (vertebrates) were found in the Cambrian strata of China. The problem of these groups suddenly BRECKENI / ISTOCKPHOTO