A view dating back to Anaximander of Miletus (6th century BP), Empedocles of Acragas (5th century BP) and Aristotle (384-322 BP) that change at all levels of organization is inherently progressive and directed toward some ideal end state of greater complexity. Starting in the 17th century and through to end of the 19th century, it was a central concept in the preformationism-epigenesis debate and became synonymous with development. Due to Herbert Spencer (1820-1903), it became restricted to biological (and cultural) evolution, but still with the connotation of progress. Charles Darwin (1809-1882) in turn removed the association with progressive change in his theory of descent with modification, a label he preferred to evolution. In this respect, his theory was different from that put forward by Alfred Russel Wallace (1823-1913).
See Biological evolution, Development, Developmental hypothesis, Epigenesis, Growth, Prefomationism, Progress, Theory of descent with modification