#dinaledi

Check out 'Homo Naledi Burial? A Public Peer Review of the Evidence'

In honor of my dad, Harold Dibble

HOMO NALEDI AND HUMANS MAY HAVE COHABITED AFRICA

New research from the University of Witswatersrand in Johannesburg suggests that the recently described hominin species, Homo naledi, may have coexisted with early humans in Africa. When the fossils of a new hominin species belonging to the same evolutionary group as humans were unearthed in the "Cradle of Humankind" region in South Africa, the world was mesmerized by the discovery. The find was the largest assemblage of hominin fossils ever to be excavated in Africa, with more than 1500 bones and fragments comprising 15 individuals found in a single chamber of the Rising Star cave system. Though Homo naledi had certain body traits similar to those of Homo sapiens, the cranial size together with their shoulders, rib-cage and pelvis resembled those of the Australopithecus genus, early hominin ancestors of humans. This led researchers to estimate that Homo naledi existed between 100,000 and 1 million years ago, classifying them alongside other early hominins of that era.

However, new evidence from the original research team showed their initial age estimates to be inaccurate. Analyses of material within the Dinaledi Chamber, the site of the excavation, showed that Homo naledi’s remains were younger than they thought. Radioactive dating of three fossilized teeth found within the cave combined with rock and sediment dating showed that the fossils were between 236,000 and 335,000 years old. This means that Homo naledi was around during the same period as early Homo sapiens, raising such questions as whether stone-age tool usage originated with humans or if it could have been a shared trait among these related hominin species.

A further discovery was found in another cave of the Rising Star system, independent from the initial Dinaledi Chamber. The Lesedi Chamber contained more fossils of Homo naledi; so far, the finds comprise 3 individuals, and excavations are ongoing. The find is especially significant because a skull that was unearthed is one of the most complete specimens from a partial skeleton of Homo naledi, and shows the cranial cavity to be 9% larger than initially measured.

The greatest thing naledi has revealed about our evolution so far is that we are a long way from understanding our complete story. The revised age of the naledi fossils raises the possibility that other species of early hominins may also be incorrectly dated, leading to further revisions of our evolutionary history. Homo naledi represents one of the earliest divergences in the hominin group; whether naledi may have been a direct ancestor of humans is still highly debated at this point, as a primitive member of the hominins, naledi had the potential to diverge into other Homo species. This research highlights the need for a more non-linear outlook to our evolutionary history: less focused on trying to find the "missing link” and more on mapping our convoluted family tree.

--KR

References and Further Reading: 2017. Second Cave Chamber Reveals Spectacular New Homo Naledi Skull and More http://voices.nationalgeographic.com/…/second-cave-chamber…/ 2015. Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa. https://elifesciences.org/content/4/e09560 2017. The age of Homo naledi and associated sediments in the Rising Star Cave, South Africa. https://elifesciences.org/content/6/e24231 2017. New fossil remains of Homo naledi from the Lesedi Chamber, South Africa. https://elifesciences.org/content/6/e24232 2017. Homo naledi and Pleistocene hominin evolution in subequatorial Africa. https://elifesciences.org/content/6/e24234

Image: Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa. https://elifesciences.org/content/4/e09560

wanted: small, skinny scientists…

Because you have to crawl through this crack in a cave in the dark and drop into a pit of bones… Indiana Jones had it so much easier… Heard on NPR: http://www.npr.org/sections/health-shots/2015/09/10/437249183/south-african-cave-yields-strange-bones-of-early-human-like-species not me boy! On 6 October 2013, Lee Berger distributed a call over social media platforms Facebook, Twitter, and…