Sensational Study of HEREDITY May Produce New Race of Men (Nov, 1934)
This article is all over the place, but the last sentence is pretty prescient considering that the discovery of DNA was still 20 years away:
“Will other unknown rays, in combination with a life-chart like Morgan’s, enable man to analyze and rearrange the genes of mankind and build a new race of supermen?
Given what I’ve learned by watching the documentary series Heroes, I think it’s clear they succeeded.
Sensational Study of HEREDITY May Produce New Race of Men
By Sterling Gleason
BLACK light, heat, and X-rays are being used by experimenters in sensational efforts to solve the mysteries of heredity. Workers in a score of laboratories in many different countries are delving for secrets locked in the living animal cell.
From their discoveries may emerge a new human race, stronger, more intelligent, and better able to resist disease. As the first step, they have produced an amazing chart by which the character of generations of flies yet unborn can be accurately foretold.
Radiations, the newest and most powerful tool of the physical sciences, are chief instruments in this biological study. Lightlike ether waves penetrate animal cells in the search for an M-ray that is asserted to control growth and death. Mysterious emanations of the human body, with the strange power to kill yeast, are being analyzed and compared with the flashes of energy given off when living cells are active or divide. Artificial races, laboratory-produced, grow for generations in the refrigerator while experimenters apply radiation from vacuum tubes or chemicals to produce types of life hitherto unknown.
In a pair of narrow-mouthed glass flasks, Dr. Calvin Bridges, an associate of Dr. Morgan famous cytologist, at California Institute of Technology, recently held in bottles two swarms of tiny gnat-like flies. From each flask he emptied hundreds of flies into small glass chambers filled with ether vapors. Succumbing instantly, the insects became motionless and were then poured out upon a gleaming white plate under the binocular microscope. Virgin females from one race and males from the other were selected for the start of a spectacular experiment. Into a tiny quartz tube Dr. Bridges put the males, then took them to the Kellogg Radiation Laboratory which houses the three-story X-ray tube producing the most penetrating rays ever controlled by man.
A low hum arose as giant oil-immersed transformers went into operation in the laboratory. A sharp hissing sound came faintly through concrete and lead walls as a million-volt flame of electricity crashed across spark gaps. A stream of invisible X-rays was being reflected from a target bidden in the cylinder of the tube which passed through the exposure room from floor to ceiling. Three seconds later, Dr. Bridges removed the X-rayed insects from their searing bath and placed them together in a flask containing a little agar, molasses, and yeast.
Within ten days, a new generation of the flies had been born. What mysterious rearrangement of the life-controlling elements, or genes, had been wrought by the influence of the X-rays? Placing the anesthetized insects under the microscope, Dr. Bridges sought the answer.
Striking abnormalities were at once apparent. The eyes of one male were bright vermilion instead of the normal dull brick red. The wings of another stood out stiffly at an angle from the body instead of folding back neatly along its sides. Still another had an extra pair of wings which no normal fly should have.
Into glass homes went the freak flies, to breed new generations of their kind. The results of these experiments were recorded by sticking push-pins with lettered heads into a tall, four-sided post, marked off by horizontal divisions. More knowledge had been added to the famous life-chart which graphically depicts how this species produces new kinds in bewildering variety.
In thick-walled vaults at California Institute of Technology, more than 700 distinct races of the tiny fly, known as Drosophila, live in refrigeratorlike vaults and reproduce their kind for the benefit of science. The insects go through their life cycle at the rate of three generators a month, thirty-six a year. Many of them have a recorded family tree which, if they were men instead of flies, would date back 15,000 years before Adam.
For forty years, scientists have known that characteristics are inherited according to a definite plan. But no one understood why freaks, unlike any known ancestor, sometimes occur. For example, there was a short-legged lamb which in the eighteenth century suddenly appeared in the flock of Seth Wright, a New England farmer, and was reared by him to produce the Ancon breed of sheep, favored because they are so short-legged they can not jump over an ordinary stone wall.
It was also known that the body contained two kinds of cellsâ€”body cells, and reproductive cells, the latter being the only link between one generation and the next. All cells multiply by division. In a growing child, each cell is believed to split at least once a day, producing millions in a month, billions in a year. But what mysterious change goes on in the reproductive cell to produce freaks, or “mutations”?
Dr. Morgan undertook to find out, using the tiny yeast fly as guinea pig. One day he made the exciting discovery that one of his flies had snow-white eyes instead of the normal brick-red. He bred the fly to produce a race of white-eyed flies and found the trait to be “sex-linked”; that is, it followed sex. Only the males of a particular generation had white eyes. Females were normal. Soon other sex-linked traits, as yellow body-color and miniature wings, appeared.
Why did these characteristics follow sex? Dr. Morgan said that whatever element in the germ cell determined sex also must contain something which caused the “mutations.”
Under the microscope the scientist could see the four pairs of rodlike chromosomes, like tiny punctuation marks. Chromosomes had already been studied intently for several decades without definite knowledge of their function. Experimenters knew them only “stainable bodies” in the central portion or nucleus of each cell. But nowâ€”Morgan was saying that one particular chromosome, which was different in males and females, must contain the genes which cause white eyes and other sex-linked characteristics, as well as sex itself.
His colleague, Dr. Bridges, soon discovered that certain freak flies with strange sex characteristicsâ€”flies half male, half femaleâ€” were seen to have new con-figuration in their chromosomes. Certain freaks were remarkable in that no part of the fly was left unchanged. Bridges found that such flies had suffered accidents resulting in broken chromosomes, the loss of a whole section of chromosomes, or sometimes the gain of an extra piece. Thus he proved that the genes which produced the characteristics are actually parts of the chromosomes.
So tiny are the chromosomes that even under the most powerful of microscopes, they can be seen only indistinctly. Then came the startling discovery that in the salivary glands of the Drosophila larva, chromosomes grew to be sixty to seventy times bigger than ordinary. In these giant cells, experimenters could see the four pairs of rods with great detail. Their banded structures were clearly visible and the point at which the chromosomes had broken and recombined could now be accurately plotted on the life-map. Years of research showed that each part of each chromosome contained specific character determiners. Each controls the development of one characteristic of the fly. Thus the genes which Morgan had suspected, actually exist as minute groupings of the chromosome material itself.
Further research has now given the world a strange life-chart. Each side of the square post on which it is built represents one of the four chromosomes. Each button with which it is studded represents a gene, controlling some physical characteristic of the fly. The experimenter can read directly upon the map what proportion of grandchildren will show any given combination of traits. This actual mapping of the microscopic chromosomes created a sensation among scientists. In thirty or more laboratories all over the world, more than a hundred workers are spending their time in filling in blank spaces of the life-chart. Twice a year a special bulletin is issued by Drs. Bridges and Demerec as an international clearing house for information.
Even with the rapidly growing Droso-phila, experimenters might have worked for years without finding more than a few of the freak types which permit them to find the genes had it not been for X-rays. Nature produces few freaks, perhaps one in several thousand generations. But under bombardment with X-rays, mysterious changes occur in the germ cells. Chromosomes are shattered and recombined in new patterns producing freak flies at 150 times the normal rate.
WHY do body cells suddenly begin to run riot and multiply at an extraordinary rate, producing the mysterious disease known as cancer? In the chromosome of the mouse, Dr. Maud Slye, of the University of Chicago, has sought the answer, carrying her researches into the living germ cell of the little rodent in much the same way that Drs. Morgan and Bridges have probed the germ-cell of Drosophila. She has found that mice can inherit a susceptibility to cancer. For twenty-four years she has bred the animals for study, beginning with a pair mated in 1910. On the laboratory operating table, she has performed more than 116,000 mouse autopsies. Breeding tests have enabled her to narrow the source of the strange liability to cancer, to a single gene located in a chromosome of the mouse. Another gene, she discovered, has the power, if inherited, to protect its possessor against the disease.
Other experiments, revealing the effect of rays on plant life have produced results almost as spectacular as those conducted upon insects and animals. Magicians of the laboratory have altered the characters of plants, changed their time of blooming and produced new varieties by exposing them to the bombardment of invisible rays.
A few years ago, Dr. L. J. Stadler, of the Missouri College of Agriculture, employed a curious portable X-ray machine to study the effect of ths rays upon growing corn. Pushed up and down the rows like a hand cultivator, the apparatus bathed each stalk with X-rays before it passed on. As a result, Dr. Stadler found curious alterations took place in the growing plants. Through his researches, he hopes to develop new and better varieties of corn and other grains.
In Berlin, Germany, scientists in a unique ray laboratory have been employing fourteen kinds of X-ray machines, as well as other curious apparatus, to study the relation of rays and plant life. Besides the X-ray aids, they have installed apparatus for producing heat rays, ultraviolet rays, light rays, as well as the super-penetrating emanations of radium. Seaweed and other forms of marine plants as well as the more familiar plants of the fields have been subjected to exhaustive tests. On the roof of the building which houses the laboratory, automatic apparatus keeps tab on the exact amount of ultra-violet reaching the earth. These researches, it is expected, will prove beneficial by giving a clearer insight into the relation of growth and rays.
Far more mysterious than man-made rays are those of nature. The light of the sun seems to engender in certain plants the power to kill the Japanese beetle. Plants are known to give off potent radiations. Prof. Lieske of Mulheim, Germany, found that certain deposits of peatlike brown coal had the power to speed growth of flowers and to bring rats and mice to swift maturity. Mysterious mitogenetic rays given off by certain growing plants seem necessary for cell division and growth. Fantastic though such experiments may seem, they open up marvelous opportunities. X-rays are harnessed to halt the ravages of cancer. Radio waves generate artificial fevers which break the grip of malaria. Electrical currents stimulate cell activity and speed circulation to ward off pneumonia. Will other unknown rays, in combination with a life-chart like Morgan’s, enable man to analyze and rearrange the genes of mankind and build a new race of supermen?