NATURE 



20I 



TsHURSDAY, MAY 15, 1919. 



DYNAMICS OF EVOLUTION. 



The Origin and Evolution of Life on the Theory 

 of Action, Reaction, and Interaction of Energy. 

 By Prof. H, F. Osborn. Pp. xxxi + 322. 

 (London: G. Bell and Sons, Ltd., 1918.) 

 Price 255. net. 



••/CONFESSION of failure," Prof. Osborn 

 ^ writes, "is part of the essential honesty 

 •of scientific thought." Wave after wave of evolu- 

 tionary theory has prompted research, but, in 

 spite of many new facts, there has been little 

 fresh enlightenment since Darwin's day. "The 

 chief causes of the orderly evolution of the germ 

 are still entirely unknown." So the author has 

 sought for a fresh starting-point— " an energy 

 conception of evolution." He would take the 

 organon of physico-chemical science for a while, 

 leaving morphology and bionomics to the end. 

 There are four main complexes of energy to be 

 considered — the inorganic environment, the 

 organism, the heredity germ, and the animate 

 environment. How are they adjusted to one 

 another? What in particular are the relations of 

 the heredity germ with the other complexes, for 

 are we not slow to learn Weismann's lesson 

 that the essential question is as to germinal e-*;olu- 

 tion, not as to bodily evolution? The heredity 

 germ remains inconceivable as regards its develop- 

 ment, its lineage, and its evolution. Thus, in his 

 preface. Prof. Osborn cleans the slate. His 

 essential honesty is a little depressing, but the 

 general idea is : We have been thinking too much 

 from Form backwards ; let us try to think from 

 Energy forwards. 



Organisms as material systems are solidary 

 with the inorganic, but they are distinguished by 

 their more dominant constructive capacities, as 

 Joly pointed out very clearly long ago. Besides 

 the actions and reactions (capturing, storing, re- 

 leasing energy) which conform to the second law 

 of thermodynamics, there is in organisms a dis- 

 tinctive dominance of "interactions " which unify 

 or integrate — e.g. nervous impulses or chemical 

 messengers. "Interaction " has to do with the 

 co-ordination, balance, co-operation, compensa- 

 tion, acceleration, and retardation of actions and 

 reactions. In the course of development there is 

 evidence of this correlating and regulating, which 

 Prof. Osborn is not felicitous in calling "the 

 directing power of heredity," The central 

 thought of the book is thus stated : "In each 

 organism the phenomena of life represent the 

 auction, reaction, and interaction of four com- 

 plexes of physico-chemical energy, namely, those 

 of (i) the inorganic environment, (2) the develop- 

 ing organism (protoplasm and body-chromatin), 

 (3) the germ or heredity-chromatin, (4) the life 

 environment. Upon the resultant actions, re- 

 actions, and interactions of potential and kinetic 

 } energy in each organism selection is constantly 

 operating wherever there is competition with the 

 XO. 2585, VOL. IO3I 



corresponding actions^ reactions, and interactions 

 of other organisms." The author is quick to 

 add that, "while this is a principle which largely 

 governs the organism, it remains to be discovered 

 whether it also governs the causes of the evolu- 

 tion of the germ." This is Prof. Osborn's "tetra- 

 kinetic " or " tetraplastic " theory. 



The constructive part of the book opens with 

 an interesting discussion of "the preparation of 

 the earth for life," the capture of the sun's heat 

 and light, the suitability of various elements to 

 function in metabolism, and similar topics. As 

 to the primary physico-chemical stages of life, the 

 following steps are speculatively suggested : The 

 assemblage of several of the ten elements now 

 essential to life, the integration of these in a 

 novel way ("a new form of unity in the cosmos ") 

 and in a state of colloidal suspension, the appear- 

 ance and specialisation of catalysers (effecting bio- 

 chemical co-ordination and correlation), the begin- 

 ning of competition and natural selection. What 

 primordial life-forms competed about we are not 

 told ; probably for a place in the sun. The attrac- 

 tive agency of hydrogen and oxygen led to the 

 incorporation of additional elements useful in 

 energy-capture. But no great progress was pos- 

 I sible until interactions were established which 

 regulated and unified metabolism ; and a vivid 

 account is given of the variety of chemical mes- 

 sengers, both general and specific, which play so 

 important a rSle in the economy of the organism. 



Prof. Osborn then passes to consider bacteria 

 as the forerunners of ordinary plant and animal 

 protists ; they show the capture, storage, and 

 utilisation of energy in simplest expression; they 

 form the primordial food supply ; they lead on to 

 the first true cells with differentiated protoplasm 

 and chromatin. Through the chromatin, excelling 

 all other substances in the complexity of its mole- 

 cular constitutionj it became easier for an 

 organism to retain its integrity amid ceaseless 

 metabolism and from generation to generation. 

 Another great step with incalculably important 

 results was implied in the appearance of chloro- 

 phyll, .which hitched organisms in a new way to 

 the sun, facilitating energy-capture enormously. 



In the second part of his book Prof. Osborn deals 

 with the evolution of animal form, and proves him- 

 self an entertaining and illuminating guide. What 

 seemed to us in earlier pages an over-emphasis on 

 the adequacy of physico-chemical formulations is 

 now corrected by a recognition of psychic 

 powers which are in an indirect way "crea- 

 tive of new form and new function." In 

 the vivid sketch of the evolution of vertebrates 

 there are \ery . valuable features, notably (a) the 

 correlation of organismal and environmental 

 changes ; (h) the illustration of adaptive radiation 

 of group after group to the twelve chief habitats ; 



(c) the continual facing of the difficulty that, 

 unless one is a thoroughgoing Lamarckian, the 

 sources of the raw materials of evolution must be 

 looked for in the heredity germ, not in the 

 organism ; in the genotype, not in the phenotype ; 



(d) the recognition of the simultnneous and oor- 



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