become distinct species. The punctuated equilibria hypothesis suggests that anagenesis is rare and that the rate of evolution is most rapid immediately after a split which will lead to cladogenesis, but does not completely rule out anagenesis. Distinguishing between anagenesis and cladogenesis is particularly relevant in the fossil record, where limited fossil preservation in time and space makes it difficult to distinguish between anagenesis, cladogenesis where one species replaces the other, or simple migration patterns. Recent evolutionary studies are looking at anagenesis and cladogenesis for possible answers in developing the hominin phylogenetic tree to understand morphological diversity and the origins of Australopithecus anamensis, and this case could possibly show anagenesis in the fossil record. When enough mutations have occurred and become stable in a population so that it is significantly differentiated from an ancestral population, a new species name may be assigned. A series of such species is collectively known as an evolutionary lineage. The various species along an evolutionary lineage are chronospecies. If the ancestral population of a chronospecies does not go extinct, then this is cladogenesis, and the ancestral population represents a paraphyletic species or paraspecies, being an evolutionary grade. This situation is quite common in species with widespread populations. In humans The modern human origins debate caused researchers to look further for answers. Researchers were curious to know if present day humans originated from Africa, or if they somehow, through anagenesis, were able to evolve from a single archaic species that lived in Afro-Eurasia. Milford H. Wolpoff is paleoanthropologist whose work done when studying human fossil records explored anagenesis as a hypothesis for hominin evolution. When looking at anagenesis in hominids, M. H. Wolpoff describes in terms of the 'single-species hypothesis,' which is characterized by thinking of the impact that culture has on a species as an adaptive system, and as an explanation to what conditions humans tend live in based on the environmental conditions, or ecological niche. When judging the effect culture has as this adaptive system, scientists must first look the modern Homo sapiens. Wolpoff contended that the ecological niche of past, extinct hominidae is distinct within the line of origin. Examining early Pliocene and late Miocenes findings helps to determine the corresponding importance of anagenesis vs. cladogenesis during the period of morphological differences. These findings propose that branches of the human and chimpanzee once diverged from each other. The hominin fossils go as far