Science

muriel_volestrangler

(101,322 posts) Thu Oct 28, 2021, 07:10 PM Oct 2021

Resolving the "muddle in the middle": The case for Homo bodoensis, a new species name

for a direct Homo sapiens ancestor, and dropping Homo heidelbergensis and Homo rhodesiensis as unhelpful groupings:

Abstract

Recent developments in the field of palaeoanthropology necessitate the suppression of two hominin taxa and the introduction of a new species of hominins to help resolve the current nebulous state of Middle Pleistocene (Chibanian) hominin taxonomy. In particular, the poorly defined and variably understood hominin taxa Homo heidelbergensis (both sensu stricto and sensu lato) and Homo rhodesiensis need to be abandoned as they fail to reflect the full range of hominin variability in the Middle Pleistocene. Instead, we propose: (1) introduction of a new taxon, Homo bodoensis sp. nov., as an early Middle Pleistocene ancestor of the Homo sapiens lineage, with a pan-African distribution that extends into the eastern Mediterranean (Southeast Europe and the Levant); (2) that many of the fossils from Western Europe (e.g. Sima de los Huesos) currently assigned to H. heidelbergensis s.s. be reassigned to Homo neanderthalensis to reflect the early appearance of Neanderthal derived traits in the Middle Pleistocene in the region; and (3) that the Middle Pleistocene Asian fossils, particularly from China, likely represent a different lineage altogether.
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Multiple, often contradictory views on what constitutes H. heidelbergensis make this taxon particularly misleading. Even to nonspecialists (e.g., biologists working in other realms, Palaeolithic archaeologists, etc.) H. heidelbergensis represents either (and sometimes paradoxically both) the generalized Middle Pleistocene hominin, or a chronospecies of Neanderthals. Within the palaeoanthropological community, the taxon's ambiguity has contributed to complex and sometimes hard-to-follow discussions: in a single paper, one can find numerous descriptions of the taxon with incompatible hypodigms.16, 19, 20, 31, 33-35, 37, 43-46 More troublingly, newly discovered Middle Pleistocene hominin fossils that cannot easily be assigned to Homo erectus, H. neanderthalensis, or early H. sapiens, still tend to be lumped into this one-size-fits-all taxon, often with a sensu lato qualifier to indicate a nonspecific morphology of a Middle Pleistocene hominin.35, 47-50 Alternatively, they are assigned more general or descriptive names like “archaic H. sapiens,”51 “mid-Pleistocene Homo,”52 or “Homo sp.,”53 which do little to convey their evolutionary position.
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Introducing a new hominin taxon

We propose that, in addition to suppressing these two taxa, we need to add a new hominin taxon that is clearly defined following ICZN rules and does not carry any social-political baggage. This taxon would have originated from the MRCA of European, Asian, and African Middle Pleistocene taxa sometime before the split of Eurasian taxa into Neanderthals and Denisovans and would represent the Middle Pleistocene ancestor of H. sapiens.