Eugenics Laboratory Lectures number 13: Pearson, Karl. 1921. Side Lights on the Evolution of Man; Being a Lecture Delivered at the Royal Institution, Friday, May 14, 1920 (London: Cambridge University Press). 27 pp.
Summary
Delivered by Karl Pearson, F.R.S., at the Royal Institution in May 1920, this lecture applies the biometrician’s quantitative methods to the study of human evolution. Pearson focuses specifically on the femur (thigh-bone) across various primates and early human forms, using forty indices or ratios of proportion rather than simple descriptive terms.
He asserts that the femur’s proportions provide key evolutionary evidence. Findings show that Palaeolithic Man (Neanderthal, Spy) possesses a highly robust femur. By calculating indices of robusticity and bicondylar ratios, Pearson demonstrates that Palaeolithic Man stands anatomically closest to the greater anthropoids (Gorilla, Chimpanzee). The modern gibbon’s femur is found to be too slender to be interpolated as a direct ancestor of man, contradicting some anthropological views.
Pearson highlights the importance of measuring proportions because, in breeding, indices (proportions) are “far harder to fix” than absolute size, making them superior indicators of evolution. He also notes that specific ”fringe” races of recent man (such as the Japanese and Australians) exhibit thigh-bone indices that stand closer to Palaeolithic Man than those of Recent European Man. The entire analysis confirms that rigorous quantitative analysis is necessary to solve the “splendid problems” of human evolution.
This paper draws on material published in the Drapers’ Company Research Memoirs. Series B. Biometric Series, number 10 and 11 by Karl Pearson and Julia Bell.
Eugenics Laboratory Lectures number 13
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