Homo erectus: Ancestor or evolutionary side branch?

Abstract Controversies in paleoanthropology wax and wane, but substantial interest is currently focused on Homo erectus. This species has traditionally been regarded as a member in good standing of the human family, where it is placed as an evolutionary intermediate between earlier Homo habilis and later Homo sapiens. Recently, however, some workers have questioned whether the species exists at all. If its populations have been transformed slowly toward the modern condition, and if continuity with living people can be demonstrated in many geographic regions, then any separation of Homo erectus from Homo sapiens must be largely arbitrary. In that case, only one species should be recognized and this slowly changing lineage would have to be called Homo sapiens. Other paleontologists adopt a different view, arguing that Homo erectus is not only anatomically distinctive but also restricted in its geographic distribution. They claim that the fossils from Java and China are so specialized in appearance that they cannot lie in the mainstream of human evolution. Homo erectus, strictly defined as limited to the Far East, probably went extinct without issue. If so, more modern populations must have evolved from another source, perhaps one outside of Asia altogether.