nensis) when it was thought to be contemporaneous with the fossils from the Gran Dolina (Mallegni et al., 2003). It is now considered to be a possible contemporary of the Sima de los Huesos population (Muttoni et al., 2009).
Let me be clear. There is no fossil in the Sima de los Huesos that could be confused with Ceprano. The same could be said for Broken Hill, Arago, or Mauer. Others, including Swanscombe, Reilingen, Steinheim, and Petralona are more similar, but not the same. Reilingen, for example, already shows an “en bombe” profile (Schwartz and Tattersall, 2002) and the Petralona extraordinary sinuses in the face and the supraorbital torus are out of the Sima de los Huesos range of variation. It is my impression that if these other sites had yielded more fossils, they would be essentially the same as those already known (i.e., there would be more remains of “cepranensis,” “petralonensis,” and “swanscombensis,” etc.) as occurred in the Sima de los Huesos and happens in any living human population, even across the entire species. If this is correct, and we may know when there are additional samples discovered, we would have other “entities” like the Sima de los Huesos. What taxonomic category should these hypothetical entities be given? Relying on the criterion of inter- vs. intrapopulation variation, they should be given that of species. If that of demes (subspecies) is preferred, it should be borne in mind that they would be demes of a strongly polytypic species, much more so than modern humans and perhaps more so than any of the extant hominoid species.
If we also have a fine chronological control for these entities, it would be possible to establish whether the evolutionary pattern that led to Neanderthals and modern humans was characterized by anagenesis or by successive speciation events. On the basis of the current state of our knowledge, reducing the human variability in Europe and Africa from the late Early Pleistocene to the middle Middle Pleistocene to a single species seems to be an exaggerated simplification.
I am grateful to Francisco J. Ayala and John C. Avise for inviting me to participate in the A. M. Sackler Colloquium “In the Light of Evolution IV: The Human Condition”; to Rolf Quam for the English translation and valuable comments; to Ignacio Martínez, Ana Gracia, and Alejandro Bonmatí for suggestions and criticism; to Américo Cerqueira for the drawing of Fig. 2.1; and to Javier Trueba for providing pictures of fossils. The Atapuerca field work is supported by Junta de Castilla y León and Fundación Atapuerca and the Atapuerca Research Project by Ministerio de Ciencia y Tecnología, Spanish Government CGL2006–13532-C03–02.