Friedrich C. Luft
Detlev Ganten
Berlin, Germany

Rudolf Virchow, born in 1821, was arguably the most important German physician, biologist, social scientist, and anthropologist of the nineteenth century. His establishment of cellular pathology is known by all and his comment that “politics is nothing more than medicine on a grand scale” is recalled by many. Less appreciated is Virchow’s extensive career as a founding anthropologist and largely forgotten is his extensive study into the racial aspect of seven million German school children. This project examined cranial dimensions (skull type), hair and eye color, body size, and demographics including religious affiliation in children throughout Germany. The unstated aim of the study was to establish the racial differences between the “Germanic” and “Jewish” races. Virchow could not distinguish between the children on the basis of his findings and concluded: “In the last analysis the differences between any two individuals are greater in magnitude than any differences between the races.” Current racial controversies and recent genomic advances addressing them would have astounded Virchow. The fact that genetic variance can be assessed to the degree that human ancestry can be traced with extreme precision, that even facial features can be genomically predicated with amazing accuracy, and that any individual can be precisely identified from a single cell is difficult to imagine, even for the well-informed observers today. In his farewell address, Virchow cautioned that scientific principles should be judged carefully and not be approached superficially.

Much has been written about Rudolf Virchow and more is expected on the 200th anniversary of his birth. Our purpose here is not to present still another laudation. Instead, we wish to comment on accusations that on the basis of his anthropological interests and investigations, Virchow was a racist and anti-Semite. Virchow was born in October 1821 in Schivelbein, Pomerania (today in Poland). His life, medical education, and scientific and political career have been extensively reviewed elsewhere.^{1, 2}

Virchow was a progressive, liberal politician for his day and even participated in the founding of his own political party, the German Progressive Party, in which he was revered by members and opponents alike. He was the founder of public health in Germany. But one thing he was certainly not: he was not a blond-haired, blue-eyed, “Aryan Type.” As a matter of fact, he was small, brown-eyed, of sallow complexion, and in no way fit into any German mythos.² Even his last name belies a Slavic rather than a Teutonic heritage. Nevertheless, he was a Prussian. Jean Louis Armand de Quatrefages de Bréau classified the Prussians as “not of Germanic origin,” as documented by their revengeful and spiteful nature.³ Quatrefages assigned the Prussians instead to the “mongoloid Finns.” This classification amused Virchow, who would be even more astounded had he known that this assumption could today easily be proved or disproved by molecular genetic technologies, even in individuals long since dead.

Social conceptions and groupings of races in the nineteenth century often involved folk taxonomies that defined essential types of individuals based on perceived traits. Today, there is broad scientific agreement that essentialist and typological conceptions of race are no longer tenable. Furthermore, the racialization of religious identity would today be viewed with deserved suspicion. Virchow was not an opponent of Darwin but was clearly interested in inspecting anthropological data addressing evolutionary theories. After he and others founded the Berlin Anthropological Society in 1869, he had ample opportunity to do so. Virchow became its president until his life’s end in 1902 (Figure 1).

Darwin’s revelations suggested that all people are indeed of one common “monogenist” stock, but the common ancestors are African apes of long ago, not Adam and Eve in the garden of Eden. Virchow was well aware of these conclusions as was his contemporary, Ernst Haeckel. However, Virchow’s interpretation of these findings was substantially different from those of Haeckel. Whereas Haeckel defined twelve “polygenist” species of living humans from the ape-like Papuans to the un-ape-like Europeans (Figure 2), Virchow rather favored a unity of the human species.⁴

During the Society’s second general assembly in Schwerin, Mecklinburg-Vorpommern, the decision was made to conduct a cross-sectional study of school children throughout Germany to assess the statistics of cranial dimensions. In the next year while meeting in Stuttgart, the project was broadened to include hair color, eye color, and assessment of religious affiliation. Skin complexion was also considered. While not specifically stated, the intentions of compiling these additional pieces of information were obvious to the attendees. What was wanted was information concerning the spread of “non-Germanic” races within the Reich. An excerpt of the typical data form is given (Figure 3). And so, the study was completed in surprisingly short order and preliminarily published in 1871.⁵ The article eventually comprised 200 pages including an extensive data supplement. Of the seven million school children, 70,000 were identified as being Jewish (1%).

Virchow used the data to deal with the issue of blond, blue-eyed types and brunette, brown-eyed types. None of the study variables could in any way separate Jewish from non-Jewish children. The appearance of phenotypes was not different amongst the groups. As a matter of fact, an increase in darker phenotypes was observed in southern, compared to northern Germany. The most heterogeneous results were identified along the great rivers Oder, Rhine, and Danube, suggesting intermingling along the major trade routes. The complete results were published in 1886. Thus, the blond, blue-eyed Teutonic phenotype was identified in about one-third of children. Indeed, the appearance of blond hair and blue eyes appeared, if anything, to be more common in Jewish children. Virchow dryly commented: “It is almost embarrassing that we must admit that in terms of ethnic groupings, Celts, Germans, Slavs, Jews, we are unable to identify any typically identifying features that allows distinguishing one group from another or to which nationality they could belong. In the last analysis, the differences between any two individuals are greater than any differences between the races.” Virchow concluded that the idea of racially classifying groups of peoples into various “types” based on external phenotypes was not possible. Instead, similar features were present in Jews and non-Jews, suggesting that both these groups had ethnicities in common.

Terminology of the times and data interpretation being as they were (or are), these data were used by the Nazis as indicating something entirely different. As a matter of fact, they used the study and Virchow’s name for their purposes of racial classification and “purity.” As is oftentimes the case, the receptive German audience at the time failed to consult the primary literature and Virchow’s paper was not studied further.

Goschler has emphasized that during Virchow’s clinical investigations, he developed serious doubts as to whether any German race existed.⁶ Furthermore, the findings caused him to question the value of the term “race” in the first place. Virchow even traveled to Finland to find out whether or not the conclusions of Quatrefages had any basis in fact. Virchow found out that in contradistinction to his own appearance, the Finns were not brachycephalic, small, and dark-complected. He took solace in the fact that he was a German, although not tall, blond, and blue-eyed as the historian Tacitus had made them out to be.

Race was a worldwide issue in the nineteenth century in all the places where Europeans had settled, namely North and South America, South Africa, the Indian Subcontinent, Australia, and New Zealand. Similar questions to those posed by Virchow were addressed by Franz Boas, an American ethnologist, linguistics expert, and geographer. Boaz originated from a Jewish family residing in Westphalia since 1670. He studied mathematics, physics, and geography in Heidelberg and Bonn. His doctoral thesis addressed the question, “Why are the ocean waters blue?” Boas addressed this question by examining the absorption, reflection, and polarization of light in water, not a bad approach to determine that water absorbs colors in the red part of the light spectrum. Boas achieved faculty rank in Berlin in 1885 (Habilitation), where he was acquainted with Virchow. He then emigrated to the United States in 1886 and was in close contact with his physician uncle, Abraham Jacobi, who had founded the medical specialty of pediatrics in New York.⁷

The American Immigration Service contracted with Boas to perform an anthropological assessment of immigrants at Ellis Island, New York, between 1908 and 1910. The variables investigated were similar to those that Virchow had addressed but more extensive. Between 1892 and 1954, millions of immigrants from Europe entered the United States while the Statue of Liberty watched in silence. Boas compared the physical characteristics of 18,000 immigrants and their foreign-born and subsequently native-born children. He discovered that the longer children had been in America, the more they resembled other children born in America and the less they resembled their immigrant parents (eye and hair color excluded). This pattern occurred regardless of where a child came from and was independent of the child’s ancestry. The results of this assessment of immigrants from Europe did not support a racial classification based on external bodily phenotypes and in essence his findings were similar to Virchow’s report. Geulen, in his essay “Blonds Preferred,” has recapitulated the results.⁸ Nevertheless, Boas’ observations had no more influence on immigration policies in the United States than Virchow’s conclusions had in Germany. Immigration quotas were established in 1910, after the United States census results at the time caused some alarm in government circles. The racist nature of the immigration policies of the United States have been discussed by Lapore elsewhere in her book, These Truths.⁹

Virchow’s findings and those of Boas would suggest a more-or-less monogenist origin but had little influence on the polygenist stance of prominent “Darwinists.” As Marks explains, these anthropologists expanded their racist ideas into a new discipline, namely eugenics.⁴ Haeckel’s classification (Figure 2) was largely embraced by Houston Chamberlain, Erwin Bauer, Eugen Fischer, Fritz Lenz, Charles Davenport, Madison Grant, and many others. This interpretation of evolution not only dehumanized large groups of people, but also rationalized their destruction. Even though Jews featured no reliable phenotypes, they were required to wear one in the form of a yellow Star of David armband. In Germany, Ottmar von Verschuer and his assistant Josef Mengele diligently looked for less obvious phenotypes such as biomarkers from blood tests. Even cranial measurements regained prominence as August Hirt had concentration camp victims murdered in order to conduct more precise skeletal measurements.

The game changer, of course, is the human genome project and modern sequencing technologies that have brought the costs of whole-genome sequencing down one millionfold since the turn of the century. We now know that we consist of 3.3 billion base pairs, of which merely 2% encodes for protein. Humans differ from one another once about every 1,000 base pairs, so that the eight billion persons presently on the planet are about 99.9% identical. This trivial difference is nonetheless sufficient to distinguish each and every person and defines each individual’s specific identity. Even identical twins have their very own fingerprint. Moreover, we are 99% identical with any chimpanzee in the neighborhood zoo and analogies between our genome and the genomes of other organisms can be traced retrograde down to single-celled organisms. The technical advances of the past two decades not only concern sequencing, but also the remarkable ability to extract ancient DNA from our forebears. Thus, we can trace an ancestral genome back to roughly 40,000 years (at present), allowing identification of Neanderthal ancestry. The remarkable field of paleogenetics allows us to determine when and from whence we came, and to where our genes have traveled.¹⁰

We shared a common ancestor with the chimpanzees on the order of five to ten million years ago. Anatomically, modern humans appeared in Africa about 200,000 years ago. Movements across Eurasia began about 60,000 years ago. Comparisons between archaic humans allow for a schematic tree illustrating gene-flow events between modern humans, Neanderthals, and Denisovans at various intervals. The spread of modern humans proceeded from Africa to Europe, to Asia, and Oceania. Once humans became distributed on different continents, the spread of any new mutations to all humans was drastically reduced and for the past 50,000 years, species-wide fixations of alleles have probably ceased.¹¹ Nevertheless, humans continue to accumulate mutations and to adapt to local environments and cultures. As a result, phenotypic differences among people in skin color, body height, facial features, and other traits have developed. These traits are highly complex and so, for example, at least 180 genes have been implicated in determining height. Establishing who we are is a function of where we are and who we would like to be. Krause and Trappe have published an assessment of European and so-called Germanic origins based on paleogenomics, which might have helped Virchow.¹² A comprehensive analysis of the 1000 Genomes Project permits projections along top principal components that demarcate populations at distinct geographic levels.¹³ Millions of informative loci along each principal component have been identified. Such genomic data can define individual populations and aspects of their evolutionary and mixing history.

Not only can genomic data give insights into where we came from, but genomic data can also be used to determine what we look like. Lippert and colleagues recruited normal volunteers, photographed each person, and from total genomic sequencing data, extensive computer power, and “artificial intelligence” reconstructed their images.¹⁴ The computer-constructed faces and the photographs rendered an astounding similarity (Figure 4). The reverse can also be performed. On the basis of photographic data, genomic sequences can be predicted to identify individuals, not yet with perfection but to a considerable degree. Since huge amounts of genomic data (23 and Me for example) are available and because people enjoy sharing their intime pictures in public portals, privacy issues become largely a moot point.

So, what is to be done with the concept of race? Marks discusses historical aspects and defines scientific racism, which he contrasts with unscientific creationism. Both threaten scholarship.⁴ Graves argues that the social definition of race has to do with colonialism and justifications of chattel and slavery.¹⁵ On the one hand, categorizing humans to justify their societal treatment has a lengthy history that remains to this day (master status). The Constitution of the United States granted persons of African origin three-fifths personhood. The same constitution counted women as people but gave them no political rights. Are they a different race? Phenotypically and genotypically they do differ from males, far more so than conventional racial differences (Europeans and Africans for instance). Native Americans were not even fitted into the Constitution and were not counted (as anything) at all.⁹ The good intentions of subsequent constitutional amendments have not resulted in a solution. For instance, the two most important provisions of the 14th Amendment to the United States Constitution guarantees that states, like the federal government, cannot “deprive any person of life, liberty or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.” Because the Supreme Court has since granted corporations the same rights as individual persons, this amendment has done far more for business interests than for minority citizens.

On the other hand, there exist biomedical and clinical reasons to retain some definition of race/ethnicity. Even after adjusting for socioeconomic indicators, environmental exposures, and many other risk factors, a greater risk of adverse health outcomes exists based in race/ethnicity.¹⁶ These differences may represent expressions of biology (sickle cell anemia or glucose-6-phosphate dehydrogenase deficiency for example) or inequities related to yet undetermined risk factors, including some resulting from societal biases, currently termed “structural racism.”

Genetic admixture or genetic exchange is an important characteristic of all populations. For instance, “Africans” exhibit considerably more genetic diversity amongst themselves than do “Europeans.” In the United States, Blacks have larger proportions of West-African than of European ancestry. Latino Americans, the fastest growing minority, have an admixture of European, Native American, and African ancestries (Figure 5). Self-classification is problematic and clinical laboratory results such as renal function (estimated glomerular filtration rate) may be incorrectly interpreted when adjusted for race. As a result, faulty clinical decisions may be made. When genomic sequencing is available for all persons, precision could be enhanced. Current efforts to sequence 100,000 patients within the National Health Service in the United Kingdom and the Million Veterans Project in the United States will cast light on these issues.¹⁷ Until then we must accept the fact that health correlates are imperfect, but nonetheless are correlated with the variable of race/ethnicity.

We can only imagine how Virchow might have reacted to this knowledge and these issues today. In his address on the occasion of his eightieth birthday, he remarked: “Important to me is to draw to your attention to how medical practice hinges on legislation. Those seeking to reconcile clinical judgements with the great open questions concerning everyday life, climatization, colonialization, and the most recent scientific insights will soon realize how dangerous it is to avoid the issues or to view them superficially.”

In that same farewell address, Virchow admonished his listeners to trust the people, to work and stand up for them, and that the rewards are great in spite of any and all adversities. Such was his creed until life’s end.¹⁸ We stand before great challenges today to better understand the notion of racism and population genomics. The future is now.

References

1. Andree C. Rudolf Virchow. Leben und Ethos eines großen Arztes. Langen Müller. 2002. ISBN 3-7844-2891-6.
2. Andree C. Rudolf Virchow, Vielseitigkeit, Genialität und Menschlichkeit. Georg Olms Verlag AG. 2009. ISBN 978-3-487-08822.
3. DeQuatrefages A. La race prussiene. Essai 1871. ISBN 978-1-542-98774-5.
4. Marks J. Why be against Darwin? Creationism, racism, and the roots of anthropology. Am J Phys Anthropol. 2012;149 Suppl 55:95-104.
5. Virchow R. Gesamtbericht über die von der deutschen anthropologischen Gesellschaft veranlassten Erhebungen über die Farbe der Haut, der Haare und der Augen der Schulkinder in Deutschland. Archiv für Anthropologie 1871.
6. Goscher. Rudolf Virchow: Mediziner – Anthropologe – Politiker. Böhlau Verlag 2002.
7. Stocking GW Jr. A Franz Boas Reader – The Shaping of American Anthropology, 1883–1911. The University of Chicago Press, Chicago 1982.
8. Geulen C. Blonde bevorzugt. Archiv für Sozialgeschichte 2000;40:147-170.
9. Lepore J. These Truths: a History of the United States. W W Norton & Co New York. 2018. ISBN 978-0-393-63524-9.
10. Paabo S. The human condition-a molecular approach. Cell. 2014;157:216-26.
11. Stoneking M and Krause J. Learning about human population history from ancient and modern genomes. Nat Rev Genet. 2011;12:603-14.
12. Krause J, Trappe T. Die Reise unserer Gene. Ullstein. 2020. ISBN 978-3-548-06234-1.
13. Padakanti S, Tiong KL, Chen YB and Yeang CH. Genotypes of informative loci from 1000 Genomes data allude evolution and mixing of human populations. Sci Rep. 2021;11:17741.
14. Lippert C, Sabatini R, Maher MC, Kang EY, Lee S, Arikan O, Harley A, Bernal A, Garst P, Lavrenko V, Yocum K, Wong T, Zhu M, Yang WY, Chang C, Lu T, Lee CWH, Hicks B, Ramakrishnan S, Tang H, Xie C, Piper J, Brewerton S, Turpaz Y, Telenti A, Roby RK, Och FJ and Venter JC. Identification of individuals by trait prediction using whole-genome sequencing data. Proc Natl Acad Sci U S A. 2017;114:10166-10171.
15. Evans M, Williams W, Graves J, Jr., Shim R and Tishkoff S. Race in Medicine – Genetic Variation, Social Categories, and Paths to Health Equity. N Engl J Med. 2021;385:e45.
16. Borrell LN, Elhawary JR, Fuentes-Afflick E, Witonsky J, Bhakta N, Wu AHB, Bibbins-Domingo K, Rodriguez-Santana JR, Lenoir MA, Gavin JR, 3rd, Kittles RA, Zaitlen NA, Wilkes DS, Powe NR, Ziv E and Burchard EG. Race and Genetic Ancestry in Medicine – A Time for Reckoning with Racism. N Engl J Med. 2021;384:474-480.
17. Magavern EF, Warren HR, Ng FL, Cabrera CP, Munroe PB and Caulfield MJ. An Academic Clinician’s Road Map to Hypertension Genomics: Recent Advances and Future Directions MMXX. Hypertension. 2021;77:284-295.
18. Fischer EP Ganten D. Die Idee des Humanen: Rudolf Virchow and Hermann von Helmholtz. Hirzel Verlag GmbH. 2021. ISBN 987-3-7776-2902-5.