HUMANITY'S FUTURE

Sun (Auckland), Volume IV, Issue 1018, 8 July 1930, Page 12

HUMANITY'S FUTURE

STIMULATING SURVEY BY BIOLOGIST PROBLEM OF THE GENES Modern biology and the future of the human race have recently been surveyed by Professor H. S. Jennings, who reaches some stimulating conclusions on tlie subject of humanity’s future as revealed by the most farreaching of sciences—modern biology. The “biological basis of human nature” begins with the single cell—the fertilised egg. The egg, or cell, “contains a great number of distinct and separable substances, existing as minute particles.” The interaction of these substances “with each other, with other parts of the cell, and with material taken from the outside,” produces Shakespeare, Beethoven, or the lowly oyster. It also produces Drosophila, the patient fruit fly, whose long martyrdom at the hands of scores of investigators during the past two or three decades is the source of much of what we know about genetics, says the “New York Times.” The important part of the egg ceU is the gene and the groups of paired strings of genes which are called chromosomes. In the simplest form of fertilised egg one string in each chromosome is front the father, the i other from the mother. The interaction of these" genes, lying side by side in regular ascertainable order, provides what Dr. Jennings calls the| “recipe" for the developing individual. . Because, in the higher orders of life, each, individual has two parents, foui grandparents, eight great-grand pare ill.', and so on; and, because, in each case, he is one of seven billion possible personalities which might have tome front the mating of his male and his female parent the “recipes” are endlessly varied. Moreover, because he j carries within himself not only the j thing he is, but also latent elements ■ which do not develop in himself, but j may appear in his descendants, he is, a possible source of billions upon billions of future variations in his j species. Proved To Exist How do we know, asks Dr. Jennings, that genes are realities? The reader cannot know, unless he has done ad-; vaneed laboratory work. But the biologist knows because he has found facts which cannot be explained with- ; out the gene. The source of his revelation was the discovery, proved bevond possible doubt, that the female of the species had one cytoplasm is part of the environment chromosomes instead of one —than the male. The wanderings of this X-ehromo-some, which not only makes every cell of a feminine organism feminine, hut also carries certain other_ characteristics, could be traced. W ith this start a map of the gene system of the fruit fly could be made and was made. It was found that, this fly had. in its X-chromosome, some 50 or more separable parts. Each one of these parts does something to the organism. It does it by affecting the cytoplasm — the substance in which the cell nucleus is embedded. Through the cytoplasm it affects the whole structure of the body. For “every one of the millions of cells of the adult body contains the complete set of paired genes." But this is not the whole story. From the very beginning the element of environment enters in. “lVhat the ! cells become depends on their sur- | roundings; on what the cells about ! them are becoming.” In a sense the I cptoylasm is part of the environment of the chromosomes, the chromosomes part of the environment of the cytoplasm. As the organism matures other environmental influences enter in, so that certain identical results are caused in one instance by the genes—that is, by heredity—and in other instances by environment. Heredity is no inexorable fate fixed upon the individual; it is a pattern which shapes itself in one way under certain conditions, in another way under other conditions. “The single human individual,” as Dr. Jennings puts it, “has not a single definite prearranged fate or tendency, but a vast number of capabilities, a vast number of keys, as it were, through which the environment may play upon him; a multitude of impulses, tendencies toward action in diverse directions.”

Dr. Jennings thus stands some- i where between the behaviourism of j Dr. John B. Watson and the crude j determinism of “eugenists” like Albert E. Wiggarn. The known facts j of biology do not lend themselves to j the belief that by proper training we can make anything we like out of any individual we like. Xor do they lend themselves to the dogma that “like j breeds like,” and that consequently i we can purify and uplift the human J race by breeding only from the wise, | the successful, and the good. The Middle Class The truth, as Dr. Jennings sees it.! is that the best of us as well as the ; worst of us come from the great bio-, logical middle class. Very likely the ! best of us carry hidden in our chromosomes the possibility of handing on feeble mindedness, sloth, and vice to our children. Likewise, the sluggards, the criminals, and the failures may be able to produce all the moral and mental virtues in some, at least, of their children. This is not to say that a million superior parents will not produce more superior children than a million mediocre or inferior parents. But we cannot be sure that any two individual parents, however superior, will produce superior children. About all we are certain of in this connection is ihat two parents who ore feeble-minded or otherwise degenerate will produce offspring like themselves—in most cases if not in ell. But, since for every feebleminded individual there are 30 normal individuals who are capable of traus- ! mitting feeble-mindedness if on' of their genes finds itself linked with a ! similar gene in another normal person, teeble-mindedness cannot be stamped out by preventing the feeble-minded from breeding. And what is true of feeble-minded holds for other latent defects. These cannot be eliminated until a defective gene in a normal person can be recognised and that person prevented from breeding. This. Dr. Jennings thinks, is not impossible’. But it is an achievement not vet in sight. Where Biology Stands What, then, is the practical application of biology to this tremendous problem? First, pending further knowledge of means of controlling hereditv other reforms must be carried tnrough. Measures of public health must be carried out, overwork and bad I conditions of living done away with. | faults of diet, both quantitave and qualitative, corrected; economic ills | conquered, grinding poverty abolishe 1

i When these things are done. wk,. j human plant is given * * ■which it can unfold its lanalM 7 | without stunting, poisoning, and » 1 ; ation by the environment, tw' 1 ' • will be possible to discover wk., Jf are due primarily to defective » and to plan such measures a^* 1 possible for their eradication. Dr. Jennings deads with the prejy of marriage, wherein he fi n< j g biological justification for nionoSi and fidelity: with the rrobfea’ racial intermixtures, wherein he uo general rule of good or eTii suits: with heredity, mutations. J*. the inheritance of acquired characS istics. the last of which, in comnL with most biologists, he regards proved; and with the profound (hjT cnee between the mechanical theon>> evolution and the emergent •yL" of evolution. He is. as might pected, uo mechanist. The * evolutionist sees all life, human a included, in the making. The futSl cannot be read from the past, nor SI entire universe from one small cora2 The author goes on:—

“Aspirations do influence the coon, of events. Thoughts, ideals, purpos? are among the determining factor for happenings in nature' . . cause things have occurred in a Attain way in the past, it does not lot low that they must thus occur in jv future. . . . Nothing in science is k! compatible with striving to realitl ideals that have never yet he2 realised.”