The directional influence of natural selection is more evident when the environment itself changes. Under these circumstances evolutionary changes occur such as to give the impression that the organism is evolving along a set path with a particular goal in view. This is quite erroneous and arises from the fact that in the context of its environment the most recent member of an evolutionary series always appears much better adapted than the earlier intermediate stages which, where they are known, look half-formed and incomplete by comparison, even though they were equally well adapted to the environment's own earlier intermediate stages. An example of this is the evolution of the horse, which developed from a small forest-living browser into a large, long-legged running grazer as its environment altered from forest to open grassy plain. The small changes that enabled it to deal most effectively with its changing environment were continually selected for throughout its history and in this way the horse evolved.