The fruit fly may have been an unromantic specimen, but scientifically it turned out to be perfect, especially after Morgan noticed that a single white-eyed male suddenly occurred among thousands of normal red-eyed flies. This sudden mutation was something worth getting to the bottom of. Over the next few months, Morgan and his team mated thousands and thousands of flies in their laboratory at Columbia University in New York. (This is how the ‘fly room’ got its name.) The sheer bulk of Morgan’s results enabled him to conclude that mutations formed in fruit flies at a steady pace. By 1912, more than twenty recessive mutants had been discovered, including one they called ‘rudimentary wings’ and another that produced ‘yellow body colour.’ But that wasn’t all. The mutations only ever occurred in one sex, males or females, never in both. This observation, that mutations are always sex-linked, was significant because it supported the idea of particulate inheritance. The only physical difference between the cells of the male fruit fly and the female lay in the ‘X body’. It followed, therefore, that the X body was a chromosome, that it determined the sex of the adult fly, and that the various mutations observed in the fly room were also carried on this body.27
Morgan published a paper on Drosophila as early as July 1910 in Science, but the full force of his argument was made in 1915 in The Mechanism of Mendelian Inheritance, the first book to air the concept of the ‘gene.’28 For Morgan and his colleagues the gene was to be understood ‘as a particular segment of the chromosome, which influenced growth in a definite way and therefore governed a specific character in the adult organism’. Morgan argued that the gene was self-replicating, transmitted unchanged from parent to offspring, mutation being the only way new genes could arise, producing new characteristics. Most importantly, mutation was a random, accidental process that could not be affected in any way by the needs of the organism. According to this argument, the inheritance of acquired characteristics was logically impossible. This was Morgan’s basic idea. It promoted a great deal of laboratory research elsewhere, especially across the United States. But in other long-established fields (like palaeontology), scientists were loath to give up non-Mendelian and even non-Darwinian ideas until the modern synthesis was formed in the 1940s (see below, chapter 20).29 There were of course complications. For example, Morgan conceded that a single adult characteristic can be controlled by more than one gene, while at the same time a single gene can affect several traits. Also important was the position of a gene on the chromosome, since its effects could occasionally be modified by neighbouring genes.
Genetics had come a long way in fifteen years, and not just empirically, but philosophically too. In some senses the gene was a more potent fundamental particle than either the electron or the atom, since it was far more directly linked to man’s humanity. The accidental and uncontrollable nature of mutation as the sole mechanism for evolutionary change, under the ‘indifferent control of natural selection,’ was considered by critics – philosophers and religious authorities – as a bleak imposition of banal forces without meaning, yet another low point in man’s descent from the high ground he had occupied when religious views had ruled the world. For the most part, Morgan did not get involved in these philosophical debates. Being an empiricist, he realised that genetics was more complicated than most eugenicists believed, and that no useful purpose could be achieved by the crude control techniques favoured by the social Darwinist zealots. Around 1914 he left the eugenics movement. He was also aware that recent results from anthropology did not support the easy certainties of the race biologists, in particular the work of a colleague whose office was only a few blocks from Columbia University on the Upper West Side of New York, at the American Museum of Natural History, located at Seventy-ninth Street and Central Park West. This man’s observations and arguments were to prove just as influential as Morgan’s.
Franz Boas was born in Minden in northwestern Germany in 1858. Originally a physicist-geographer, he became an anthropologist as a result of his interest in Eskimos. He moved to America to write for Science magazine, then transferred to the American Museum of Natural History in New York as a curator. Small, dark-haired, with a very high forehead, Boas had a relaxed, agreeable manner. At the turn of the century he studied several groups of native Americans, examining the art of the Indians of the north Pacific Coast and the secret societies of the Kwakiutl Indians, near Vancouver. Following the fashion of the time for craniometry, he also became interested in the development of children and devised a range of physical measurements in what he called the ‘Cephalic Index.’30 The wide diversity of Boas’s work and his indefatigable research made him famous, and with Sir James Frazer, author of The Golden Bough, he helped establish anthropology as a respected field of study. As a consequence he was called upon to record the native American population for the U.S. Census in 1900 and asked to undertake research for the Dillingham Commission of the U.S. Senate. This report, published in 1910, was the result of various unformed eugenic worries among politicians – that America was attracting too many immigrants of the ‘wrong sort,’ that the ‘melting pot’ approach might not always work, and that the descendants of immigrants might, for reasons of race, culture, or intelligence, be unable or unwilling to assimilate.31 This is a not unfamiliar argument, even today, but in 1910 the fears of the restrictionists were rather odd, considered from this end of the century. Their anxieties centred upon the physical dimensions of immigrants, specifically that they were ‘degenerate’ stock. Boas was asked to make a biometric assessment of a sample of immigrant parents and children, an impertinence as controversial then as it would be scandalous now. With the new science of genetics making waves, many were convinced that physical type was determined solely by heredity. Boas showed that in fact immigrants assimilated rapidly, taking barely one or at most two generations to fall in line with the host population on almost any measure you care to name. As Boas, himself an immigrant, sharply pointed out, newcomers do not subject themselves to the traumas of emigration, an arduous and long journey, merely to stand out in their new country. Most want a quiet life and prosperity.32
Despite Boas’s contribution, the Dillingham Commission Report – eighteen volumes of it – concluded that immigrants from Mediterranean regions were ‘biologically inferior’ to other immigrants. The report did not, however, recommend the exclusion of ‘degenerate races,’ concentrating its fire instead on ‘degenerate individuals’ who were to be identified by a test of reading and writing.*33
Given the commission’s conclusions, the second book Boas published that year took on added significance. The Mind of Primitive Man soon became a classic of social science: it was well known in Britain, and the German version was later burned by the Nazis. Boas was not so much an imaginative anthropologist as a measurer and statistician. Like Morgan he was an empiricist and a researcher, concerned to make anthropology as ‘hard’ a science as possible and intent on studying ‘objective’ things, like height, weight, and head size. He had also travelled, got to know several different races or ethnic groups, and was highly conscious that, for most Americans at least, their contact with other races was limited to the American Negro.