Human evolution news: Announcement of Homo naledi

Exciting news of a surprising fossil collection found deep in a cave. Was this a burial site? A hiding place? Even the age is unclear. But it’s fascinating.

A trove of bones hidden deep within a South African cave represents a new species of human ancestor, scientists announced Thursday in the journal eLife. Homo naledi, as they call it, appears very primitive in some respects—it had a tiny brain, for instance, and apelike shoulders for climbing. But in other ways it looks remarkably like modern humans. When did it live? Where does it fit in the human family tree? And how did its bones get into the deepest hidden chamber of the cave—could such a primitive creature have been disposing of its dead intentionally?

This is the story of one of the greatest fossil discoveries of the past half century, and of what it might mean for our understanding of human evolution.

Source: This Face Changes the Human Story. But How?

The assemblage of fossils appears to be of all the same species which shares some features with known hominids and differs as well in primitive and derived characteristics. It’s not clear where this new population fits in the human evolutionary line so to call it a “human ancestor” is likely incorrect. We SHARE a common ancestor.

Named the Dinaledi collection, the paper says this is the richest assemblage of fossil hominins (members of the human evolutionary clade) ever discovered in Africa, with a comprehensive representation of skeletal elements from individuals from young to old.

Artists rendition from Homo naledi fossils.

Artists rendition from Homo naledi fossils.

More:

New species of extinct human found in cave may rewrite history – New Scientist (well illustrated)

Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa | eLife – the full paper

Abstract:

Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa.

It’s assumed that the discussion about this new find is JUST beginning and will continue for a while as the community studies it and come to perhaps different conclusions. One interesting note from the paper is this: “In light of this evidence from complete skeletal samples, we must abandon the expectation that any small fragment of the anatomy can provide singular insight about the evolutionary relationships of fossil hominins.” A warning that we can’t speculate too much from a small piece. The H. naledi material has suggested that basically the entire skeleton is needed to make a clear distinction on what the organism looked like and how it functioned.

Evolution: It just is. Amazing.

  4 comments for “Human evolution news: Announcement of Homo naledi

  1. Karl
    September 10, 2015 at 12:12 PM

    It seems like it took several years, lots of debate, and several papers from different research groups for scientist to generally agree “the hobbit” was a new Homo species. Can one or two papers from a single researcher really establish a new Homo species? Maybe the differences are so clear and can’t all be explained by genetic defects?

  2. MisterNeutron
    September 11, 2015 at 7:38 AM

    What’s remarkable about this find is that we’re not talking about small bits and pieces of one individual. There are thousands of bones – so far, from at least 15 individuals, almost certainly with more to come. One specimen might show some genetic defects, but not an entire population.

  3. Blargh
    September 11, 2015 at 12:43 PM

    Well shucks. I actually passed by the Cradle of Humankind today, and might just have had an hour or two to spare to at least swing by the visitor centre.

  4. September 19, 2015 at 11:02 AM

    Fantastic find, but no burial: Homo or Australopithecus naledi simply died in the swamp of the forest where they lived (google Homo econiche). Lowland gorillas regularly (google Nodiki gorilla) & other great-apes occasionally wade upright in forest swamps, in search for sedges etc., but naledi had flatter feet (cf duck & seal, vs ostrich & antelope) than extant apes, suggesting they spent a lot more time wading & swimming in the swamp than lowland gorillas do (google aquarboreal), and their very curved hand phalanges suggest they also climbed arms overhead in the branches above. When they died in the swamp, their corpses got covered with mud, later the swamp dried up, and the mud + bones slid into the cave?

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