The processes of life are chemical and consist of either linkage of materials or the breaking of links with the hurly burly of an environment providing the initial breaks. However, the making of links is more complex for life forms, because of the wide variety of links that can be made between carbon compounds and the need to select the materials to be linked, and the exact places on molecules where links are to be made. (Dennis, McNair, and Kauffman, The Mereon Matrix, p. 321)