Human evolution; early fossils are rare (Introduction)

by David Turell , Tuesday, September 24, 2019, 22:47 (1676 days ago) @ David Turell

And not all findings are available for study by many experts:

https://inference-review.com/article/access-all-areas

"Paleoanthropologists reconstruct human history from scant and enigmatic traces of a distant past—often from little more than a handful of objects. The human fossils that form the basis for the discipline are hard to find and not much easier to study. In a highly competitive environment where research material, economic resources, and intellectual property rights are at stake, new discoveries are, at times, closely guarded by their finders. Competition both drives and constrains research as, perhaps inevitably, personal interests become intertwined with questions about our heritage. In recent years, the development of powerful tools for digitization and analysis have provided paleoanthropologists with new ways to preserve and circulate fossil data. For all these reasons, it is time to reconsider our current vision for paleoanthropological research and propose better procedures.

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"the identification of a new human species was often a complicated and drawn-out process. First proposed in 1863, the notion of Homo neanderthalensis as a distinct species of archaic humans was only embraced at the beginning of the twentieth century after numerous additional specimens had been found. Similarly, Homo erectus and Australopithecus africanus were not widely accepted in the field for several decades after being described in 1894 and 1925, respectively. Even in the last 30 years, the identification of the oldest known hominids—Ardipithecus ramidus, Sahelanthropus tchadensis, and Orrorin tugenensis—has been the subject of vigorous debate among paleoanthropologists. The same is also true for the identification of Homo floresiensis and, more recently, Homo naledi.

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"For decades, the oldest fossils attributed to Homo sapiens were the remains found between 1967 and 1974 at the Omo Kibish site in Ethiopia and dated to 195,000 years ago. The oldest found outside Africa were those unearthed at Qafzeh in Israel and dated to 90,000 years ago. In 2017, specimens found at the Jebel Irhoud site in Morocco were re-dated to roughly 280,000 to 350,000 years ago.3 The following year, a fossil from the Misliya site in Israel was dated to between 177,000 and 194,000 years ago.

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"Another limitation involves the conservation and sharing of data. The question of ownership, not to mention the management of data, is far from straightforward in some countries. Ideally, custodian institutions would be responsible for generating the raw digital data for the objects in their collections. In France, imagery obtained for scientific research is free of copyright since it is an objective replica of a specimen, without any artistic or personal contribution. All the tomographic data generated from the anthropological collections of the Muséum national d’histoire naturelle in Paris are available for any scientific project.

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"Long-held paleoanthropological conventions were turned on their head following the discovery of Homo naledi in South Africa in 2013. This was a significant discovery for numerous reasons, chief among them being the age of the fossils. The specimens are relatively recent, dating from around 300,000 years ago, yet they possess anatomical characteristics reminiscent of the very first members of the genus Homo—the skull of naledi has similarities to that of habilis, which lived two million years ago. The identification of a species with such ancient features that lived almost at the same time as Homo sapiens and Neanderthals was a stunning development.

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"Since the first papers announcing the discovery were published, there have been numerous studies that have fleshed out the initial descriptions. Still, the novel approaches and speed with which Homo naledi was presented to the field proved polarizing. The way the discovery was handled has been the subject of much debate and generated considerable criticism. Judging from earlier discoveries, this mixed reception should come as no surprise. Such a significant announcement will also inevitably overshadow other specimens and hypotheses, particularly when accompanied by widespread media coverage.

"In contrast to the Homo naledi specimens, the fossils of other species that might form the basis for worthwhile comparisons, are accessible only to varying degrees and in some cases not at all. An exhaustive comparative study would be impossible for the simple reason that access to the material from other important discoveries is often limited to just a few tens of specimens. It is for this reason that the release of the high-resolution Homo naledi scans is an event, in my view, almost as striking as the announcement of the new species and represents a significant milestone in the development of the field."

Comment: No wonder H. sapiens ancestry is so confusing. Expect many more specimens before it clears up.