Lateral and Vertical Transfer in Biology, Linguistics and Anthropology: An Account of Widely Neglected Ideas in the Formation of Evolutionary Theories

The scope of this paper is to highlight models of reticulate evolution in a dual sense: (1) by stressing the importance of early models of horizontal/lateral transfer instead of models of unilinear vertical transfer in biology, linguistics, anthropology and related disciplines, and (2) by demonstrating that the acceptance of evolutionism as leitmotif in the nineteenth century was only possible by intense and repeated networks between scholars of different academic realms which lead to the assumption that the development of biological species and human cultures could be perceived as part of the same co-evolutionary process. Contrary to these widely popularized models of unilinear evolution, I would like to draw attention to alternative theories emphasizing the horizontal transfer of words, phenotypes/genotypes, and culture traits. Examples are the method of areal typology in linguistics, the theory of endosymbiosis in biology, and the anti-evolutionist attitude in Boasian anthropology, combined with an emphasis on the diffusion of culture traits. Further, it shall be pointed out that, even when—after the general dismissal of evolutionist ideas in the beginning of the twentieth century—the idea of co-evolutionary processes in the development of human populations and languages was again forwarded in the late twentieth century, this ‘modern synthesis’ of genetics, linguistics and archeology relied largely on interdisciplinary reticulations between sciences and humanities and serves as another example of reticulate evolution.