Leonard Darwin Scholarship of the Eugenics Society

Posted in Anthropology, Articles, New Media on 2011-11-02 03:58Z by Steven

Leonard Darwin Scholarship of the Eugenics Society

Volume 138, Number 3496 (1936-11-31)
page 756
DOI: 10.1038/138756a0

The Eugenics Society has established a second Leonard Darwin scholarship, which is to be devoted to the investigation of racial crossing. The first holder is J. C. Trevor, a graduate of Oxford in anthropology, who has spent the last two years studying mixtures of negro and white stocks in the United States, with the aid of a Commonwealth fellowship. He has collected ethnological material in the Virgin Islands and in East Africa, and with Dr. Dudley Buxton has made an investigation of English medieval skulls. He has also a collection of biometric material on West African and American negro crania. Mr. Trevor will devote a year to a survey of the literature on the subject of inter-racial crossing

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Some anthropological characteristics of hybrid populations

Posted in Anthropology, Articles, Media Archive on 2011-03-15 01:17Z by Steven

Some anthropological characteristics of hybrid populations

The Eugenics Review
Volume 30, Number 1 (April 1938)
pages 21-31

J. C. Trevor, Leonard Darwin Research Fellow

It should be explained that “hybrid” is used here in its restricted zoological sense, viz. as relating to intraspecific rather than to interspecific crosses. The adjective “mixed,” though convenient, can be misleading, since there is no acceptable definition of what constitutes a “pure” human race. For the purposes of the present discussion, “hybrid” will be taken to apply to crosses between races comprised within different major divisions of mankind such as the “varieties” of Blumenbach and the main “groups” of Haddon, Hooton and other anthropological systematists…

..The nine hybrid series concerned in this paper may be briefly described as follows:

(1) Norfolk Islanders, 113 adult male and female subjects, the descendants of six mutineers of H.M.S. Bounty and from ten to twelve Polynesian women from Tahiti and possibly two of its neighbouring islands, measured and described by Shapiro (1929). They are compared with 153 male and female Society Islanders, whose measurements were taken by Handy and reduced by Shapiro, and with 6,975 “English” and 381 Oxfordfshire villagers, whose measurements were taken by Galton and by Buxton and Blackood, respectively, and reduced by the writer. The genealogical records of the Norfolk Islanders have been carefully kept since about 1790, and any influx of fresh blood invarably been noted.

(2) Half-Blood Sioux, 77 adult male subjects including some described as a quarter and others as three-quarters Indian, whose meaurements were taken by Boas and eight assistants and reduced by Sullivan (1920). European ancestry is said to be French, Scotch, English and Irish. They are compared with 540 full-blood Sioux, measured by the same observers, and with 727 “Old American” Whites, measured and described Hrdlicka (1925). Herskovits (1930) has provided several constants of variation for the last series, and the writer a few others.

(3) Ojibwa-Whites, 8o adult male subjects, principally from Minnesota, representing various degrees of intermixture between women and French and Scotch which has been “continuous and cumulative” since 1660. They are described by Jenks (1916) and have been compared with 24 full-blood Ojibwa (all that could be obtained) and with 100 Minnesota French and 50 Minnesota Scotch, also measured by them. The constants of variation of these four studies have been computed by the writer.

(4) Yucatecans, 88o adult male subjects, a product of intermixture between Spanish immigrants into Mexico and Maya Indians during a period of some 350 years, measured and described by Williams (1931). They are compared with 77 presumably unmixed Mayas, measured and described by Steggerda (1932b), and with 416 Andalusians measured and described by Hulse (1933), for stature, and 79 subjects from all parts of Spain, whose measurements were taken by Barras and reduced by Williams, for cephalic and facial characters.

(5) Jamaican “Browns,” 165 male and female subjects of mixed White and Negro ancestry from Jamaica, measured by Steggerda and described by Davenport and himself (1929). They are compared with one series of 100 Whites of British and German descent and with another of 105 full-blood Negroes, also measured by Steggerda, both coming from the island of Jamaica and its dependencies. The Whites cannot be said to represent ideal comparative material, and as a large proportion of immature subjects is included in all three series, means based on their absolute measurements would appear to be unreliable. Consequently only indices, which are less likely to be affected by possible growth changes, have been used in the present comparison. It is unfortunate that the means and constants of variation provided by Davenport and Steggerda were determined by very crude statistical methods and that mistakes also occur in their computation.

(6) American Negroes of Mixed Blood, 254 adult male subjects of European and Negro ancestry, principally from various parts of the United States, measured and described by Herskovits (1930). Genealogies were obtained from each subject, who was then classified with regard to the proportions of White and Negro ancestry he possessed, three main divisions being recognized: (i) more Negro than White, (ii) approximately equal amounts of Negro and White, and (iii) more White than Negro. The number of individuals in each of these divisions makes them, in general, adequate for separate statistical treatment. They are compared with an unmixed American Negro series of 109 individuals, also measured by Herskovits, and with Hrdlicka’s “Old Americans.”

(7) Boer-Hottentot Crosses (the so-called “Bastaards” of Rehoboth), 74 adult male subjects of six or seven generations of mixed Boer and Hottentot descent from South-West Africa, measured and described by Fischer (1913). Fischer, like Herskovits, divides his material into genealogical classes representing different proportions of Boer and Hottentot ancestry. None of these, however, is really large enough for statistical purposes, and the measurements have been pooled to form a general Bastaard series, which is compared with 74 Hottentots, measured by Schultze Jena (1928), and, in default of local Boers, with 70 Dutch, whose forbears come from the northern provinces of the Netherlands, measured and described by Steggerda (4932a). The general Bastaard constants of variation and those of the Hottentots have been computed by the writer.

(8) Kisar Mestizos, 132 adult male and female subjects of mixed Dutch and Indonesian ancestry from Kisar, a small island in the Sunda archipelago, some thirty-five miles east of Timor. They were measured and described by Rodenwaldt (1927), who ascribes their origin to the seventeenth century. The mestizos are divided by him into genealogical classes, but these are too small for satisfactory statistical analysis, and the material has again to be treated as a whole. For comparative purposes, 64 Kisarese, also measured by Rodenwaldt, and Steggerda’s Dutch are used.

(9) Anglo-Indians, “new style,” 145 adult male subjects of mixed European and Indian ancestry from Calcutta, whose measurements were taken by Annandale, first reduced by Mahalanobis (1922-31) and later, with the exclusion of some immature individuals, by the writer. There is almost a complete absence of reliable information concerning their origin and it has been found impossible to select suitable material from Indian senes for a comparison of means, though in view of their very complex racial antecedents they can be retained for the study of variability…

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Race Crossing in Man (Eugenics Lab. Mem. XXXVI) [Review]

Posted in Anthropology, Articles, Book/Video Reviews, Media Archive on 2011-02-21 04:15Z by Steven

Race Crossing in Man (Eugenics Lab. Mem. XXXVI) [Review]

American Journal of Human Genetics
Volume 6, Number 1 (March 1954)
pages 195–196

Kenneth S. Brown
University of Chicago

By J. C. Trevor, New York: Cambridge University Press, 1953, Pp. 45

This brief monograph is a mixed blessing. On one hand it demonstrates what a wealth of metrical material has been collected on human hybrid populations, while on the other it presents methods of analysis which are both inefficient and ineptly applied.

In his preferatory note, Dr. L. S. Penrose points out that this work was done prior to the start of hostilities in 1939, but that the value of the data presented is timeless. This is very true, however the analysis made of the data is rapidly showing signs of age. The data are a compilation of published records of nine outstanding cases of biracial crossing; Hybrid American Negroes, Jamaican ‘Browns’, Half-Blood Sioux, Ojibwa-Whites, Yucatecans, Rehoboth Bastaards, Kisar Mestizos, Norfolk Islanders, and Anglo-Indians. The mean and standard error are recorded for stature and seven cranial measures for most of these populations. Additional measurements are noted for many. In each population studied the sample includes 25 or more adult (20 years or over) individuals of each sex. The values for each sex are recorded separately.

The mean of the hybrid population is compared with that of each of its propositus population groups by the use of Student’s t test. Unfortunately this test requires the assumption that the variances of the populations being compared be the same. Nowhere in the presentation is this recognized. It would have been eminently desirable to determine the significance of the variance ratio for each parameter for each pair of populations compared before the t test was applied. For cases of significant difference in variance between the populations the Fisher-Behrens method for the use of t with samples of unequal variance would be applicable.

The variability of the propositus and hybrid populations is considered separately by the method of Mourant in which the variance ratio of each character for each population pair is found and then the mean variance ratio for each pair determined. This analysis indicated that the variance of the hybrid population is greater, but was found, by a t test, to be significantly greater in only two cases. Here it would have seemed desirable to look up the values in a table of F to get a more powerful estimate of the difference between these populations.

The material presented in this monograph provides a good addition to the blood group, dermatoglyphic, and taster frequency data which are currently used in the analysis of population dynamics, and should serve to attract the attention of interested workers to this relatively undeveloped body of information.

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“Race Crossing in Man: The Analysis of Metrical Characters” [Review by L. C. Dunn]

Posted in Anthropology, Articles, Book/Video Reviews on 2011-02-20 21:09Z by Steven

“Race Crossing in Man: The Analysis of Metrical Characters” [Review by L. C. Dunn]

Race Crossing in Man: The Analysis of Metrical Characters. J. C. Trevor (“Eugenics Laboratory Memoirs,” XXXVI.) London: Cambridge University Press, 1953. 45 pp., 1 plate.

American Anthropologist
Volume 56, Issue 5
(October 1954)
pages 923-924
DOI: 10.1525/aa.1954.56.5.02a00490

L. C. Dunn
Columbia University

This is a review and analysis of nine selected sets of data published before 1938. Those cases were chosen in which anthropological measurements of living “hybrid” subjects were available, together with measurements of known or assumed parent racial groups. All involved marriage between European and non-European parents. Trevor’s chief interest was to test by existing data two opinions frequently held by anthropologists: first, that the average values of physical characters of hybrid groups are intermediate between those of the parent races; and second, that populations derived from crosses of distinct races are highly variable and often show bimodal or multimodal frequency distributions. By use of adequate biometrical methods the first opinion is sustained; the second clearly is not. The absence of the anticipated high variability of hybrids was a surprise to the author, who asks whether variability might have been reduced by the tendency of hybrid groups to be inbred. He considers this possible. The reviewer would suggest that inbreeding has two effects relevant to this question: first, reduction of heterozygosity within each related group; second, a tendency toward divergence between different family or clan groups leading toward increased variance of the total population which is so divided. Much would depend on whether the hybrid population was dispersed as in the case of American Negroes, or concentrated and localized as in the case of the Norfolk Islanders. It is doubtful whether any data now exist by which such questions can be adequately tested for human groups. The variability of mensurable traits in all human populations may be such as to render imperceptible the differences due to differing degrees of “hybridity” within and between races. Trevor’s paper is a contribution to the methodology of analysis of such difficult questions as those mentioned, and a challenge to anthropologists to produce more and better data to which the methods can be applied.

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