May, 1932 



EVOLUTION 



Page eleven 



and forwarded to the museum several tons of slabs collected 

 along the Hermit Trail, all showing fossils and foot prints, 

 most of them by large amphibians now extinct. 



There are no modern mammals nor (lowering plants repre- 

 sented in the canyon walls as the rim is composed of rocks 

 belonging to the Triassic period which antedated the develop- 

 ment of such forms. Over a mile of rock is there, but the 

 remaining mile of later deposits is nowhere represented in the 

 Canyon walls. To find it we must travel north to the high 

 plateau in Northern Utah and ascend a gigantic stair whose 

 steps are made of the Jurassic, Cretaceous, and Eocene, to a 

 point one mile higher than the Canyon rim. 



Beginnig with the lowest stratified rock in the Canyon, 

 there is layer after layer of limestone, sandstone or shale, 

 with occasional intrusions of lava, gneiss and schist. All of 

 this represents the deposits in water of the debris of earlier 

 rocks, the first of which (Cambrian) is placed by Barrell at 



550 to 700 millions of years ago. Assuming that the Canyon 

 area was at one time made up of rocks separating the entire 

 geological series, there must now be enough time allowed for 

 the denudition of one mile of rock until the Triassic is 

 reached. Then the story of the Grand Canyon itself really 

 begins. Add the time that it took the Colorado river to 

 scour out the present chasm a mile and a quarter deep, with 

 the process still going on, for it is deeper today than it was 

 yesterday. Years in Geology mean as little as miles in Astro- 

 nomy and both may be subject to error. This much however 

 is certain, the story of the Grand Canyon must be read in 

 terms of hundreds of millons of years, emphasizing once 

 more the fact that the earth's history can only be read by 

 the eye of the scientist and interpreted by his type of mind. 

 The hasteless, restless factors of geological change have been 

 writing all through the ages a flat contradiction of all ac- 

 counts of miraculous creations. 



Biochemistry Supports Evolution 



By H. GIDEON WELLS 



Professor of Pathology, University of Chicago 



Y 



N 1859, when Darwin put the subject of evolution on the 

 front page of the daily papers and on all the pages of the 

 religious journals, biologic science was mostly a matter of 

 morphology and classihcation, as befits a young science. 

 Physiology had not become sufficiently developed as a distinct 

 field of science for the establishment of a Physiological So- 

 ciety of London until 1875, four years after Darwin's second 

 great contribution, The Descent of Man, had been published. 

 Necessarily the considerations of evolution in its early 

 years were based on the evidence then available, which was 

 almost exclusively structural, and because of this sort of en- 

 vironment in infancy its subsequent career has largely de- 

 pended on morphological contributions and considerations. 

 But in 1926 Leathes in his presidential address to the Section 

 on Physiology of the British Medical Association pointed out 

 that ''natural selection applies to the survival of chemical 

 forms of living matter as it does to complex living organisms. 

 . . . Function alone gives permanence to structure." Therefore 

 it is essential that function, with all that it involves, receive full 

 consideration in working out the course of the evolution of 

 the living world of today. 



Origin of Living Matter 



Biologic function certainly depends more on chemical 

 properties than on anatomic organization. Formless enzymes 

 may function -actively, whereas the most elaborate anatomic 

 structures in our museum jars function not at all, because 

 their enzymes are dead. The evolution of life presumably had 

 first to be the evolution of proteins, carbohydrates and fats, 

 which then somehow constituted the living, probably at first 

 formless, matter, and these were the important first steps in 

 evolution. All the later strange divergencies into such elabo- 

 % rate creatures as cabbages and kings are of minor import. 



Therefore one turns to chemistry to see if it can offer a 

 solution of the problem of the origin of life. Such explana- 

 tions of the origin of life on the earth as that it is the result 



Excerpts from article in Arcfiives of Pathology, May 1930. 



of the transportation of spores by meteors or star dust, even 

 it true, are no solution, since they merely push back the ori- 

 gin of life to some other part of the universe. One may sus- 

 pect that the origin of life was the sequel of the formation of 

 inorganic colloids, which served as the antecedents of the 

 formation of organic colloids. 



The evidence of geology clearly shows that life in some 

 form appeared promptly when conditions of temperature 

 made it possible, since the oldest sedimentary rocks show 

 that already there were living forms that had much to do with 

 the formation of these early strata of the world's crust. Un- 

 der the influence of light, formaldehyde polymerizes to 

 produce substances which reduce copper solutions as do the 

 carbohydrates. It is further possible for this formaldehyde in 

 the presence of nitrates or nitrites to produce substances that 

 can build up to form amino acids, and hence the funda- 

 mental steps in the evolution of carbohydrates or proteins are 

 possible in the absence of living precursors, — only carbon di- 

 oxide, water, nitrites and sunlight are necessary. 



If, as Moore suggested, life began by the development of 

 formless colloidal complexes, capable of accelerating syn- 

 thesis under the influence of light rays, there still remains an 

 unexplained wide gap between such hypothetical chemically 

 active colloidal masses and the simplest microscopically visi- 

 ble living forms, the bacteria. Possibly, the invisible, filtrable 

 viruses represent an intermediate stage antecedent to the bac- 

 teria, but there is no knowledge as to how much real struc- 

 ture viruses have, or how many sorts there may be which 

 can not be recognized, because only those that produce 

 disease make themselves known. 



Presumably, the next stage in the evolution of life lies in 

 those bacteria which can grow on inorganic mediums and 

 synthesize their proteins, fats and carbohydrates from carbon 

 dioxide and inorganic nitrogen, sulphur and phosphorus com- 

 pounds. 



The step from such synthesizing bacteria to the algae with 

 chlorophyll was probably the next important phase in the 



