Science

Scientists ask for renaming species of modern human ancestors

The Homo bodoensis would become direct ancestor of Homo Sapiens

Scientists want to change the taxonomy of some human species by suppressing two denominations and creating a new one that would become our direct ancestor: the Homo bodoensis.

Bodo skull found in Ethiopia in 1976
Bodo skull found in 1976 in Ethiopia is suggested to be part of a new hominin species: the Homo bodoensis | © National Museum of Natural History

On October 28, scientists in an article called Resolving the “muddle in the middle”: The case for Homo bodoensis, advocate for clarifying a confused part of the evolution about hominin species that happened half a million years ago.

And it could directly affect the history branch of all humans living today, part of the Homo sapiens species.

The number of early human species who lived through history is subject to debate among scientists but about 21 of different hominin species are currently accepted.

And the authors, Mirjana Roksandic and Predrag Radović, propose to reshuffle the classification by adding a new species and removing two others.

The proposition corresponds to the Middle Pleistocene age, also named Chibanian, which is a time span between 774,000 and 129,000 years ago.

The period is rather complex with a lot a variability among our human ancestors. And the terminology doesn’t acknowledge correctly human evolution. The goal of the change would be to build “more robust explanatory models that better describe hominin evolution“.

In anthropology, species are a different concept from the animal kingdom where different species cannot reproduce with other groups. “Species, in our case, is a language thing, not a biological thing” told one of the co-authors to Business Insider.

Anthropologists use the designations to separate ancestor groups with similar characteristics or geographic ranges.

Are Homo heidelbergensis early Neanderthals?

Homo sapiens appeared 300,000 years ago. And paleontology today suggests that we most likely evolved from Homo heidelbergensis, the common ancestor we share with Neanderthals. Neanderthals are considered as our closest extinct human relatives; they lived 400,000 years ago and were extinct about 40,000 years ago.

But the definition of the Homo heidelbergensis confused scientists because very different fossils found around the same period throughout Africa, Europe and Asia were grouped together under the same terminology.

As a consequence, the paper asks to remove the Homo heidelbergensis, along with the Homo rhodesiensis species, from the current hominin taxonomy because they “they fail to reflect the full range of hominin variability in the Middle Pleistocene“.

With the help of DNA evidence, the fossils from Western Europe classified as Homo heidelbergensis would actually become Homo neanderthalensis in order to “better reflect the early appearance of Neanderthal derived traits the region“, the authors explain.

For the same reason, some Asian fossils – particularly those found in China – also classified as Homo heidelbergensis would then represent one or several distinct unnamed lineages because of a much more complex hominin variability than originally anticipated.

Moreover, they propose to add a new species: the Homo bodoensis. It is an ancestor of the Homo sapiens lineage who lived mostly in all of Africa but also in the eastern Mediterranean region (Southeast Europe and the Levant).

Bodoensis would share a common ancestor with Neanderthals and Denisovans, another human relative, and would represent the ancestor of H. sapiens during the Middle Pleistocene.

The name Homo bodoensis comes from a skull found in Bodo D’ar in Ethiopia in 1976.

But some critics claim Homo heidelbergensis should not be removed but be more restrictive and that another name for the Bodo fossils already exists and takes precedence.

Read more about Ethiopia

Source
Resolving the “muddle in the middle”: The case for Homo bodoensis sp. nov., Wiley Online Library, October 2021, Free accessAfter reevaluating humanity's fossil record, a group of experts designated a new species of human ancestor, Business Insider, October 2021, Free accessSpecies, National Museum of Natural History, Free access
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