THE UTILITY OF DEATH 



Evolution Could Not Take Place without It, Because the Higher Forms of Life 



Are so Specialized that They Cannot Change Much in a Single Lifetime — 



Death Therefore an Adaptation for the Benefit of the Species — 



the Trend of Evolution^ 



F. H. Pike 



Department of Physiology, Columbia University, New York 



THE question why living organisms 

 should die is a biological question 

 just as truly as is the question 

 why or how they live, and it 

 should be possible therefore to formulate 

 in terms of the great biological processes 

 and of the properties of living matter 

 some general considerations on the 

 significance of death. 



If we consider the processes of or- 

 ganic evolution in terms of the proper- 

 ties of living matter we find that certain 

 characteristics have been ascribed to all 

 living organisms, the most important 

 characteristics as generally given in the 

 literature being irritability or excita- 

 bilit}^ metabolism and reproduction. 

 Other characteristics have sometimes 

 been given, and in the older lists, one 

 usually noted death as one of these 

 general characteristics. Claude Ber- 

 nard insisted that "evolution is one of 

 the most important traits of living or- 

 ganisms and hence of life." But 

 whether evolution is regarded as a sepa- 

 rate and distinct characteristic of living 

 matter, or as the inevitable result of the 

 operation of the other three properties, 

 the physiologist should always keep 

 it in mind in any discussion of general 

 biological problems. Another property 

 of living matter is the power of regula- 

 tion of its internal conditions. 



A living organism has been defined as 

 a vortex [tourhillon, Cuvier) of which 

 the direction is constant and which 

 sweeps along molecules always of the 

 same sort, but into which the individual 

 molecules enter and from which the}^ 



continually depart. As Goodrich has 

 expressed it,^ "the metabolic process in 

 living matter draws in inorganic sub- 

 stances and force at one end, and parts 

 with it at the other; it is inconceivable 

 that these should, as it were, pass out- 

 side of the boundaries of the physico- 

 chemical world, out of range of the so- 

 called physico-chemical laws, at one 

 point to reenter them at another." It 

 is perfectly true that we cannot give an 

 account of all of the changes of matter 

 and energy which occur in living mat- 

 ter, but that is not exactly the same 

 as saying that there are unknown and 

 unknowable processes in living matter 

 which never can be described in terms 

 of changes of matter and energy. And 

 before we can give a final account of the 

 processes of organic evolution, we must 

 be able to tell what are the changes of 

 matter and energy underlying the 

 changes of position and changes of form, 

 which now constitute the greater part 

 of the subject matter of evolution. 



THE ORIGIN OF LIFE 



The origin of living matter must go 

 back of the origin of cells (Goodrich, 

 p. 16) to the synthesis of organic com- 

 pounds. But the precise manner of 

 origin of these organic compounds is not 

 for us to consider now. Let it be re- 

 membered, however, that the conditions 

 of organic synthesis may not have been 

 greatly different in the former ages of the 

 earth from what they are today (Cham- 

 berlin). Further, there must have been 

 a continuous and unbroken series of 



1 Read before the thirteenth annual meeting of the American Genetic Association on Decem- 

 ber 26, 1916, in New York City. 



^ Evolution, p. 15. London, 1912. 



195 



