In:
eLife, eLife Sciences Publications, Ltd, Vol. 6 ( 2017-05-09)
Abstract:
Species of ancient humans and the extinct relatives of our ancestors are typically described from a limited number of fossils. However, this was not the case with Homo naledi. More than 1500 fossils representing at least 15 individuals of this species were unearthed from the Rising Star cave system in South Africa between 2013 and 2014. Found deep underground in the Dinaledi Chamber, the H. naledi fossils are the largest collection of a single species of an ancient human-relative discovered in Africa. After the discovery was reported, a number of questions still remained. Not least among these questions was: how old were the fossils? The material was undated, and predictions ranged from anywhere between 2 million years old and 100,000 years old. H. naledi shared several traits with the most primitive of our ancient relatives, including its small brain. As a result, many scientists guessed that H. naledi was an old species in our family tree, and possibly one of the earliest species to evolve in the genus Homo. Now, Dirks et al. – who include many of the researchers who were involved in the discovery of H. naledi – report that the fossils are most likely between 236,000 and 335,000 years old. These dates are based on measuring the concentration of radioactive elements, and the damage caused by these elements (which accumulates over time), in three fossilized teeth, plus surrounding rock and sediments from the cave chamber. Importantly, the most crucial tests were carried out at independent laboratories around the world, and the scientists conducted the tests without knowing the results of the other laboratories. Dirks et al. took these extra steps to make sure that the results obtained were reproducible and unbiased. The estimated dates are much more recent than many had predicted, and mean that H. naledi was alive at the same time as the earliest members of our own species – which most likely evolved between 300,000 and 200,000 years ago. These new findings demonstrate why it can be unwise to try to predict the age of a fossil based only on its appearance, and emphasize the importance of dating specimens via independent tests. Finally in two related reports, Berger et al. suggest how a primitive-looking species like H. naledi survived more recently than many would have predicted, while Hawks et al. describe the discovery of more H. naledi fossils from a separate chamber in the same cave system.
Type of Medium:
Online Resource
ISSN:
2050-084X
DOI:
10.7554/eLife.24231.001
DOI:
10.7554/eLife.24231.002
DOI:
10.7554/eLife.24231.003
DOI:
10.7554/eLife.24231.004
DOI:
10.7554/eLife.24231.005
DOI:
10.7554/eLife.24231.006
DOI:
10.7554/eLife.24231.007
DOI:
10.7554/eLife.24231.008
DOI:
10.7554/eLife.24231.009
DOI:
10.7554/eLife.24231.010
DOI:
10.7554/eLife.24231.011
DOI:
10.7554/eLife.24231.012
DOI:
10.7554/eLife.24231.013
DOI:
10.7554/eLife.24231.014
DOI:
10.7554/eLife.24231.015
DOI:
10.7554/eLife.24231.016
DOI:
10.7554/eLife.24231.017
DOI:
10.7554/eLife.24231.018
DOI:
10.7554/eLife.24231.019
DOI:
10.7554/eLife.24231.020
DOI:
10.7554/eLife.24231.021
DOI:
10.7554/eLife.24231.022
DOI:
10.7554/eLife.24231.023
DOI:
10.7554/eLife.24231.024
DOI:
10.7554/eLife.24231.025
DOI:
10.7554/eLife.24231.026
DOI:
10.7554/eLife.24231.027
DOI:
10.7554/eLife.24231.028
Language:
English
Publisher:
eLife Sciences Publications, Ltd
Publication Date:
2017
detail.hit.zdb_id:
2687154-3
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