EVOLUTION BY HYBRIDIZATION 



Review of a Book by J. P. Lotsy — Interesting Views Regarding Origin of Variability 



Set Forth — Extreme Mechanistic Hypothesis Upheld by Author — 



Analogies Presented Are Interesting but Do Not 



Constitute Real Scientific Argument 



E. C. Jeffrey, 



Botanical Laboratories, Harvard College, Cambridge, Mass. 



IN THE slender volume which serves 

 as the basis of the present observa- 

 tions, Dr. Lotsy has put forward very 

 interesting views as to the origin of 

 variability. As is well known, Charles 

 Darwin accepted variation as a funda- 

 mental and unexplainable quality of 

 living matter, acted upon by natural 

 selection for the production of new 

 species. The great English biologist 

 held that the most significant variations 

 were as a rule small ones, which only 

 became accentuated in the process of 

 time as a result of the cumulative action 

 of the process of selection. More 

 recently De Vries on the botanical side 

 has put forward the view that new 

 species originate full armed, as it were, 

 by the mysterious process of mutation, 

 which takes place in certain instances — 

 for example, in a considerable number of 

 species of the American genus Oenothera, 

 under conditions which have not yet 

 been satisfactorily explained. The au- 

 thor under discussion puts forward the 

 extreme hypothesis that all variability 

 in living beings is due to crossing or 

 hybridization. ^ 



Lotsy's attitude is mechanistic in 

 the extreme, as ma}^ be inferred from 

 the following italicized statement from 

 his book, the italics being his: ''The 

 problem of the species and its origin is 

 consequently comparable to that of the 

 pure chemical substance and its origin, 

 the problem of the heterozygotes of differ- 

 ent constitutions which we find in nature 

 and of their origin is comparable to the 

 problem of the ores found in nature and 

 their origin." 



It is difficult indeed to see anything 



in common between a hybrid and an 

 ore (compound) of iron or copper found 

 in nature. This extreme laxity of com- 

 parison is all the more surprising, as 

 the author states on a later page (144), 

 "So one reaches all kinds of attractive 

 but quite unfounded conclusions, as 

 /. i. (by which the author means for 

 instance) , the flapper {sic!) of a seal is a 

 m.etamorphosed hind leg {sic!) of a land 

 animal, which conclusion is about as 

 well founded as that the door of my 

 house is a metamorphosis {sic!) of the 

 door of my neighbor's {sic!)." Quite 

 aside from any obvious criticism of the 

 author's English, he clearly labors under 

 the elementary error of supposing that 

 the flipper of a seal represents the 

 posterior appendage of a land inammal, 

 and he further supposes that evolution- 

 ists still hold to the antiquated doctrine 

 of metamorphosis. 



Charles Darwin with characteristic 

 honesty admitted his indebtedness to 

 Paley's " Evidences of Christianity," 

 which he was forced to study in college, 

 in acquiring a clear and logical method 

 of reasoning. It would apparently be 

 well for the mechanistic biologists, who 

 swarm at the present time, to admit also 

 their indebtedness to the oldest if not 

 the least dogmatic of the sciences, 

 theology. If they had the grace to do 

 so, their debt would doubtless be to 

 Bishop Butler's famous "Analogy of 

 Religion." Lotsy's comparison of hy- 

 brids with metal ores is on all fours with 

 the well-known Butlerian argument 

 that the human worm will enjoy a future 

 winged state because the lowly cater- 

 pil]ar later becomes the resplendent 



1 Evolution by Means of Hybridization, by J. P. Lotsy. The Hague, Martinus Nijhoff, 1916. 



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