Page Twelve 



EVOLUTION 



June. 1937 



special significance in this judgement of a scholar who is 

 in the van of recent genetics. 



2. The Britannica also secured an entirely- new article 

 on e\olution, written by Professor Goodrich of Oxford 

 He argues that "the case against Darwin" has not been 

 established. He speaks of "the process of natural selection 

 whereb\' adaptation is brought about" — which is a more 

 sweeping claim than Darwin made. He says that no hard- 

 and-fast line can be drawn between "sports" (i.e. large 

 mutations) and small variations. He specificall)' denies 

 that De Vries distinction between mutations and small 

 \ariations is valid. 



3. The chief concern of H. G. Wells and his advisers 

 when the\' wrote the Science of Life was to expound the 

 views that are considered safest by the specialists. Here 

 is their decision about Natural Selection: "The broad 

 propositions of Darwin reemerge from a scrutiny of the 

 most exacting sort essentially unchanged . . . What has 

 three quarters of a century done to modifv Darwin's view? 

 Our answer is 'Practically nothing'." 



4. J. B. S. Haldane is a Cambridge geneticist whose 

 opinion on anv subject in his field carries weight. He 

 testifies: "No satisfactory cause of evolution other than 

 the action of natural selection has ever been put forward 

 .... No facts definitely irreconcilable with Darwinism 

 have been discovered in the sixty years and more that 

 have elapsed since the formulation of Darwin's view .... 

 Darwin's ideas still hold the field today." 



5. Sir J. .\rthur Thomson, the veteran maker of a 

 long list of dependable hooks on biological subjects, is al- 

 wa\'s most careful to present both sides of a case. Yet 

 he is not ambiguous about Natural Selection: "What has 

 happened during the domestication of animals and the 

 culti\'ation of plants is closely parallel to what has happen- 



ed in Wild Nature in the evolution of new species." 

 (Riddles of Science). This is a neat summary of Darwin's 

 entire argument, and a complete endorsement of it, 



(). In The Coming and Evolution of Life, Professor 

 Crampton of Barnard College thus expresses his judgment: 

 "AH of the discoveries up to the present time have thus 

 corroborated the essential tenets of Darwin's formula of 

 the dvnamics of evolution — i.e , the natural selection of 

 congenital characteristics." 



7. Professor L. L. Woodruff in his Animal Biology. 

 says of Darwinism: "The consensus of opinion is that 

 natural selection in general is the guiding principle under- 

 1\ ing the establishment of the adapti\e complexes of organ- 

 isms .... So this is essentially a clarified Darwinism .... 

 Natural selection still affords the onl}' explanation of that 

 co-ordinated adaptation which per\ades every form of life." 



8. Man.\- an intellectual has expressed his distrust of 

 Darv\inism in the Nev: Republic during the past decade. 

 Therefore Julian Huxley's verdict in favor of Darwinism 

 had special point when it was published in the New 

 Republic: "Whereas at first onl_\' large mutations, pro- 

 ducing striking effects, were known, intensive study has 

 re\ealed that small mutations are more numerous, and also 

 more important as raw material for evolution . . . Selec- 

 tion is the main agent which directs and guides that 

 change. . . . Observation and analytic studies of genetics 

 can all be reconciled in the fundamentally Darwinian idea 

 of gradual change, due to the accumulation of small Men- 

 delian mutations under the influence of natural selection." 



Julian Huxley's finding is that "We can all be Dar- 

 winian again." So we can. There is no longer any need 

 to be troubled by the factional disagreements of the 

 specialists. Evolution remains Darwinian. 



Amateur Science 



ROBIN THE THRUSH 

 By Pauline Dederer 



One sure sign of Spring is the Robin 

 returning from his southern wintering, 

 finding plentiful Spring food in the 

 worms and seeds of man's lawns. His 

 red breast is sufficiently distinctive to 

 identify him to everyone, but is ver\ 

 misleading as to his relationships. He 

 really belongs to the Thrush famil\' 

 and we all know they have spotted 

 breasts. Nevertheless, the Robin is a 

 Thrush, spots or no spots. He may 

 hide it from himself, but his young- 

 sters give him awa}'. Watch them as 

 they hatch and grow up. Look care- 

 fuUj' at their breasts. They do have 

 spots on their breasts, a bit faint per- 

 haps, but still spots, just like an>- 

 other Thrush. Very probably, the 

 common ancestor of the Robin and his 

 relatives was just a spotted Thrush. 

 The Robin, as it e\olved, lost those 

 spots, but its youngsters, by way of 

 summing up the ancestral history in 

 their individual lives, go through that 

 old Thrush stage before assuming the 

 recentl}' acquired red breast. Incident- 

 ally, the common Bluebird (not the 



Blue Jay, who belongs with the 

 Crows) is also a Thrush, only in his 

 case the secret is fairh' safe; his 

 %oungsters do not give him away, they 

 have no breast spots. But that ab- 

 sence of spots does not mean a thing, 

 they are still Thrushes, as we know 

 from other resemblances, onl>- they 

 have gotten over their ancestry more 

 thoroughly than the Robin young. 



Question Box 



FILTERABLE VIRUSES 



By Lucy Orenstein 



O. What is meant b\' a "filterable 

 virus"? I have heard this term used 

 in connection with certain diseases like 

 hydrophobia and measles. — .4 Reader. 



A. Filterable Viruses are among the 

 most provoking of organisms because 

 of their elusiveness. They are ultra- 

 microscopic, that is, they cannot be 

 seen even under our most powerful 

 microscopes. They are also filterable, 

 that is, they pass right through our 

 finest filters made of porcelain or 

 special earth. Such filters will trap 

 bacteria and protozoa but cannot catch 

 these viruses. .Any knowledge that we 

 have of the filterable viruses is know- 

 ledge of their activities in certain dis- 



eases, rather than of their structure or 

 appearance 



It is even questioned whether these 

 tiny particles are living organisms, al- 

 though they are generally accepted as 

 such. .All our knowledge concerning 

 them is very recent. The latest in- 

 vestigations suggest the possibility 

 that filterable viruses may be the 

 border-line between the non-living and 

 living worlds. 



Not only human diseases are caus- 

 ed by filterable viruses. A disease of 

 tobacco known as leaf mosaic disease 

 has been studied widely by scientists 

 interested in filterable virus. Foot and 

 mouth disease in cattle, psittacosis, the 

 rabbit disease which received so much 

 attention lately because it is communi- 

 cable to man, are other examples. 

 .Among the human diseases believed to 

 be caused by filterable virus are 

 measles, smallpox, influenza, hydro- 

 phobia or rabies, and common colds. 



The interest in the subject of filter- 

 able virus is a two-fold one. There is 

 its relation to disease, which alone 

 would tempt scientists to pursue the 

 subject. There is also the possibility 

 that an understanding of these elusive 

 substances or organisms may bring us 

 closer to an understanding of the very 

 nature of life itself. It may be that 

 the ke\- to life's origin lies, right here! 



