"THE ORIGIN OF SPECIES."

Otago Daily Times, Issue 14684, 18 November 1909, Page 2

"THE ORIGIN OF SPECIES."

— 1 DARWIN AND NATURAL SELECTION. Twenty-four years ago Iluxley, Charles Darwin's stiuincliest disciplo, eaid 1 " What-, ever lie the ultimate verdict of posterity upon this or that opinion which Mr Darwin propounded, whatever, adumbrations or anticipations of his doctrine may be found in the- writings of his predecessors, the broad fact remains that since the publication, and by reason of the publication, of 'The Origin of Spccies,' the fundamental conceptions and the aims of the student of living nature have been completely changed. But the impulse thus given to scientific thought rapidly spread beyond tho ordinarily recognised limits of biology. Psychology, ethics, cosmology wove stirred to their foundations, and tho jrigin of species proved itself to bo the fixed point which the general doctrine needed in order to move the world."

Dr Kcnhani, delivering on Tuesday evening, beforo a meeting of members of the Otugo Institute, his paper on "The Fiftieth Anniversary of thr Origin of Species," quoted this statement made by Huxley, and proceeded to show in what manner Darwin's book had aifeoted scientilic investigation during the 50 years immediately succeeding its publication. But Dr Bonham explained that he did not propose to take the line ol leuat resistance, which would lie in recalling tho life 'ind theory of Darwin, but to attempt, so far as time permitted, to indicate the more important contributions to (he theory .which purported to explain how organic evolution had come about. This the doctor proceeded to do in a very thorough and yuite instruct,ive manner. Tho evidence that had boon gathered together by Darwin in 1859 had multiplied a hundred times in ensuing years, and ill all the wide holds of investigation nothing had been discovered which was in any way antagonistic to evolution. The early observational method of research had been, in later years, replaced by the statistical and experimental. In Intel years there had been-many eminent biologists who wished to attribute to other agencies that .vhieh was believed to, have been attained by | natural selection.

These differences of opinion had led tininstructed laymen to rejoice at the fall of Darwinism and the overthrow of evolution. ''But," said the lecturer, "it cannot be too frequently nor too strongly emphasised that, even if Darwin's theory of natural selection were proved to bo-with-out foundation, the fact of evolution would not be affected in the slightest degree." Every theory of evolution defended on two fundamental phenomena occurring throughout the realm of living things: variation tending to produce novelties, and thus funrishiug tlio raw material of e\olution, and heredity, which handed on the novelty to sucecediiig generations. Each, of i-he.se phenomena had been the object of intense study since tho publication of Darwin's book.

\ ariation be due to two causes: the action of ourroundings on the organism after birth, or a change already present in the organism at birih. A critical study ol congenital variations in the animal and "o-etaule kin-,'dolus, and a carcful analysis had shown that- there was a general resemblance between creatures of be same kpetics. Xnere were vacations, of course, nut followed the mathematical law of the Distribution of Erroi. And it was uj an accumulution of these, during sue* CG&a.'ve that Darwin natural selection to work. Other 'evoiutionisis, however, believed in what was t'.jilcil Definite or Determinate Vari-a* fin" "~ tl,at WaS Van ' ltion alon S a definite

In contradistinction to )lie current belief lial, .si, "fits are slowly changing into new types, the theory of mutation assumes that new apccies and varieties are produced from

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existing forms by sudden leap?. The parent type remain* unchanged, while giving oil' new forms at irregular periods. Variegated innimka was an instance J his, -mil the speaker mentioned other similar phenomena in life. If such cases wore indiuatiVt> of what Often occurred in Nature, tlio populnr conception of the evolution process must lie modified. If a new elementary species may arise, ready made lit a single jump, then it. w , s n „t noce-siiry to hold to the formula that species have arisen by 'lie "I'iiduiil acoiinmiil ion, under selection, of minute individual variations. I'l-wecding to show how the mutation theory, as a basis fur evolution, was delicient, l)r Honham •■•aid: "ft is no f, enough to consider even ||i great detail this or flint particular ami limited series of facts, 'out duo attention must, bo paid to the various other facts and linos of cognate phenomena concerned, that su'itts t.j Ili the reason why these subsidiary theories of evolution have failed to command the almost universal adherence that Darwin's hypothesis has." In zoology the theory of mutation was ot 110 value. turning to heredity, and the fact that certain characteristics of both father untl mot tier appear in the offspring, the lechucr pioceedccj to explain, as tur us was possible, how the ultra-mbrc-copieal particles endow od with this or that character arc gathered from all purls of the body, to he stoio;l in the genu cells, and again distributed during development to i hoi 1* appropriate places in the booty of the offspring. \\eisinnnn .suggested the germ plasm theory, the hcrcditiibli' ntl-stonca brought by the male and female eel's to the ogg is distributed equally through the two parts into which the rgg in the- course of its development naturally falls. The creature 's horn, coii'laining equal pcrtions of each parent, tMid this process repeating itself generation aflat* generation., each being actually represents an evor-incronsing lino of ancestois. Hie material of inheritance is a mosaic of ancestral plasms." The repeated division of th?_egg cell did not alfect., however, the entire muss of the gorm plasm' some of whieli remainetj intact, and was handed (lown direct to the next generation of germ cells.

The foregoing may serve to indicate ihc oxta-ernely interesting nature of Dr Een'ham's pap:?r, which, closely reasoned, illustrated Ijj- mea.ns of <liat!"runis and churls, and containing quotations from and references to many ominentscicntists, must have proved a source of instruction to those who so attentively listened to him. At the conelusion of the meeting Dr Benliam was, on the motion of Mr D. B. Waters, cordially tanked.