Paul Alsberg (1883-1965) et le transfert adaptatif du biologique au   technique : un pr\'ecurseur de la "cultural niche construction" ?
  We propose, in this paper, both a presentation and a discussion of Paul Alsberg's thesis on the supposed specificity principle of human evolution. The author maintains a difference of nature between Man and Animal relying on an opposition between "body-adaptation" - that of the Animal - and "extrabodily-adaptation" - that of Man in which the means of adaptation are switched outside of the organisms by tool-using. This difference is not a mere difference of state, but of evolutionary dynamics. Here, Man is not simply "Homo faber", as in Bergson's view, but produced and made possible by technique; a technique which then appears as an hominisation factor. Thus, his "principle of body-liberation" by tool-using is to be retrospectively understood as a part of the logics of the modification of selection pressure logics, which reminds us the seminal contemporary niche construction theory (F. John Odling-Smee). It seems therefore possible to make Paul Alsberg, from his 1922 work, one of the most important precursors of the cultural niche construction theory. 
G\'erald Fournier (LEPS)