Excerpts from Genetics:



Excerpts from “Human Inheritance,”

The Nature of the World and of Man (1927)

by Eliot R. Downing

The past two centuries have been marked by man’s rapidly increasing control of the physical world. He has harnessed mighty steam and deft electricity, and by their aid has multiplied wealth and consequently physical comforts; he has cut continents in two and pierced mountain barriers, he has explored the mysterious frontiers of the universe and forced the invisible atom to reveal its structure. His control of his biological environment is progressing with amazing rapidity. He is restricting disease, reshaping plants and animals to suit his needs, increasing the productivity of species that cater to his wants and eliminating those that antagonize his interests. Man has made least progress in the control of his social environment. Just now he is intensely conscious of the need of such control and ambitious to accomplish it . . .

Science can contribute to this latest attempt at social control at least a clear-cut notion of the limitations of the field of “euthenics,” which is the science that deals with the problems of the improvement of the social environment, as contrasted with the field of “eugenics,” which is the science that deals with the problems of the improvement of the human stock. Apparently our potentialities are determined by inheritance; the opportunity they will have to develop, by the physical and social environment . . .

The potency of inheritance in human life is well shown by Galton’s studies of identical twins [Inquiries into Human Faculties (1883)] . . . The identity has been so close in certain instances that young children could not tell their own father from his twin brother; teachers spanked both for fear the guilty one would escape punishment . . . Such twins arise from the same fertilized egg. Galton found in the eighty-three pairs of identical twins studied that even when they were separated in early life and lived in quite unlike environments, they remained very similar, not only in physical characteristics but in mental traits . . .

There is a constantly increasing mass of evidence that man’s physical and mental characters are transmitted in accordance with the laws of heredity that apply to other organisms. Of physical characters there is a long list that behave as simple Mendelian dominants . . . The brown color of the eye is due to the deposit of pigment in the outer portion of the iris. If this pigment is absent the eye is blue . . . If pigmentation is entirely wanting the eye is pink, as in albinos, because then the blood-filled capillaries show . . .

There are many human physical characters that behave as recessives, as for instance albinism, left-handedness, deaf-mutism . . . In the albino individual pigmentation is lacking or partly absent . . .

There seems to be good evidence that mental traits in man are also inherited, though we cannot yet tell the type of inheritance with the same degree of certainty as in the case of physical characters . . .

Galton in his studies of the families of distinguished English judges [Hereditary Genius (1869)], found . . . that the son of an English judge is 500 times as likely to be a person of note as the son of the average Englishman. . . .

The family of Charles Darwin . . . will make the general statement concrete. Darwin’s father was an eminent physician, a member of the Royal Society, as was also his grandfather. The latter was author of a treatise on evolution. Charles Darwin married his own cousin, Emma Wedgewood, whose grandfather was the founder of the famous potteries and himself a member of the Royal Society. Four of Darwin’s sons are eminent and members of the Royal Society, as are also two of his grandsons. Darwin’s aunt married into another family of note, and her son is Sir Francis Galton, the originator of the term “eugenics” and of the science that bears that name . . .

In the Bach family of noted musicians, of whom Johann Sebastian Bach is the best known, there were in six generations 47 musicians of repute, 29 of whom were really noted . . .

It seems equally true that the undesirable mental characteristics of dysgenic stocks are heritable. There is the famous, or rather infamous, case of the Max Jukes. A drunken ne’er-do-well called Max moved from New York City to the country . . . taking with him a prostitute named

Ada . . . Others of loose morals followed and from this little colony of reprobates a progeny of over 2,000 has been traced by Dugdale and Estabrook [The Jukes Family (1877)]. Over 600 of this number are feeble-minded, more than 300 paupers. There are 300 prostitutes in the lot, 140 criminals including 7 murderers. Not one of them has completed a common school education. Only 20 of them have learned a trade and 10 of these learned it in prison . . .

There is one striking family history that almost serves as a eugenic experiment. Martin Kallikak (the name is fictitious) just before the Revolutionary war had an illegitimate child by a feeble-minded girl. She gave rise to 480 descendants that have been traced and all have been found subnormal in intelligence . . .

Manifestly it is impossible to tell just how much of such transmission of desirable and undesirable characters is due to physical inheritance, and how much to the perpetuation of favorable or unfavorable home or other social environment . . . It seems probable . . . that such striking contrasts as those between the Darwin and Bach families, on the one hand, and the Max Jukes and Kallikaks, on the other, must largely be due to inheritance rather than to environment . . .

There seems to be considerable evidence that a tendency to insanity is inherited . . . Not infrequently a family manifests a variety of abnormal mental conditions such as feeble-mindedness, insanity, epilepsy, alcoholism, as if a degenerate stock were expressing its degeneracy in a variety of neuroses.

The burden of all these dysgenic elements in the population is heavy and is increasing. There are some 500,000 feeble-minded individuals in our population, of whom only about one-tenth are in institutions. These defectives comprise the idiots, with a mental age of 2 years or under; the imbeciles, with a mental age of 3-7; and the morons, with a mental age

8-12 . . .

At present we are in the grip of hereditary forces, drifting toward a goal we do not know, powerless because of inadequate knowledge to direct our course in this matter of racial miscegenation. The challenge to the investigative energy, wisdom, and courage of the coming generation is apparent. [419-439]

1) What are the arguments made by Downing in these excerpts?

2) Why is historical context necessary in order to understand Downing’s argument?

3) How would one argue against Downing’s point of view? Be specific.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download