Russian émigrés Roman Jakobson and Nikolai Trubetzkoy disseminated insights of Russian grammarians in Prague, but also the evolutionary theory of Lev Berg, arguing for teleology of language change. As Berg's theory failed to gain popularity outside the Soviet Union, the organic aspect of functionalism was diminished, and Jakobson adopted a standard model of functional explanation from Ernst Nagel's philosophy of science. It is, then, the same mode of explanation as in biology and social sciences;[1] but it became emphasised that the word 'adaptation' is not to be understood in linguistics in the same meaning as in biology.[6]