Geoffroy's theory was not a theory of common descent, but a working-out of existing potential in a given type. For him, the environment causes a direct induction of organic change. This opinion Ernst Mayr labels as 'Geoffroyism'. It is definitely not what Lamarck believed (for Lamarck, a change in "habits" is what changes the animal). The "direct" effect of environment is not believed today by any main-stream evolutionist; even Sir William Lawrence knew by 1816 that climate does not directly cause the differences between human races.