Cave of Bones: A True Story of Discovery, Adventure, and Human Origins

ARCHAEOLOGY AND THE FREEDOM OF HOMININS

Who is Homo Naledi and what does he/she – of course, he/she, not “it” as Lee Berger often says, since he is part of our genus, hence a close relative of ours – represent in the Homo genus?

Naledi was discovered in the Rising Star cave system in South Africa in 2013. This very complex cave system is the only place where a great number of fossils were found in various chambers of the complex. Naledi was never found outside, but was he/she looked for outside? We do not know what life he/she had outside the caves. When Lee Berger says that Naledi could have had some sexual contact with Homo Sapiens who was starting to evolve close by, he has no proof at all, and it will take some time to be able to get Naledi's DNA to see if it can be traced in Homo Sapiens' DNA. So far, we could even consider Naledi is a caveman only living in the complete darkness of the caves as a nocturnal Hominin that would have nocturnal vision. But it is not sure at all since we are going to see that they had fire, and one chamber was used as a cooking area with bones from various small mammal species that live more or less exclusively on the surface of the earth.

The time bracket of its existence is 335,000-235,000 BCE. Homo Sapiens started emerging around 300,000 BCE. The time bracket has been determined only from the dating Lee Berger's team could get for the caves and the various minerals they could find. That explains that Naledi is seen in his (absolutely no mention of women) period of full development with no indication about where they came from, what phylogenic process governed their emergence, and which or what Hominin, who was present in this area of Southern Africa before the 335,000 BCE date, they descended from. We already have here three questions that will have to be solved later: the DNA of Homo Naledi, the geographical and phylogenic origin of Homo Naledi, and the life pattern they had, like cave living, surface activities, social order, the role of women, contact with other Hominins in the area and time. We can say the research is just starting. But Lee Berger and his team have proved quite a few things. I will accept his remarks and conclusions on the basis that it is endorsed by National Geographic which has a good scientific reputation. Some of these conclusions are highly controversial with standard academics and for standard scientific conformity. The conclusions have to be confirmed by further research. Note here the long section on the whole line of the emergence of Homo Sapiens from Ardipithecus Ramidus positioned before “4 million” years ago as opposed to Homo Sapiens identified pages 32-33 as “now.”

We have to note that this is very superficial since each one of these branches is the result of mutations on the branch from which it or they deviate. It is of course not complete. Many particular Hominin fossils are missing, like Homo Heidelbergensis for Neanderthals. But this gives an idea of the complexity of the Hominin family and of the Homo Genus. As for Naledi, we do not have any clue about who he/she is descending from by mutation. And speaking of descendants refers to sexualized reproduction. Naledi being so different from the simple physical average norms of other Hominins, is it a set of mutations and a new branch appeared on the trunk that generalized in two or three generations, (obviously, it did not, since it disappeared around 235,000 BCE, did he/she not disappear? Then where is he/she?), or is it a haphazard and whimsical mutation, or set of mutations that caused a consensual or segregational bringing together, but outside the main source-Hominin community, of these smaller Hominins in an environment, the caves, in which a normal size Hominin could not easily circulate, if at all, let alone live.

Just to help you visualize the cave system here are some Pictures. First one horizontal projection, then two vertical projections, neither 3D projections.

The physical (no real physiology since we only have bone fossils) summary is given on page 200:
1- “a small brain.”
2- “a frame built for climbing.”
3- “a pelvis and a trunk, as some earliest human relatives did.”
4- “long legs.”
5- “human-shaped feet.”
6- “hands that included thumbs suited for toolmaking.”
7- “small, human size teeth.”
Each characteristic (here numbered by me) deserves a comment.

The small cranial capacity of 465–610 cm3 (28.4–37.2 cu in), compared with 1,270–1,330 cm3 (78–81 cu in) has to be corrected with the EQ of the species. The Encephalization Quotient (EQ) is the volume of the brain compared to the mass of the body. And this element is never alluded to in the book. It brings in two other elements, the size, and the weight: Naledis are estimated to have averaged 143.6 cm (4 ft 9 in) in height and 39.7 kg (88 lb.) in weight, yielding a small Encephalization Quotient of 4.5. If compared to an EQ of 10, the difference in size is a lot less flagrant: minimum [(465 : 4.5) x 10 = 1,033], maximum [(610 : 4.5) x 10 = 1,355]. But this assumes that the brains of both Naledi and Sapiens are comparable, meaning have the same structure, the same architecture, and the same general functioning as the center of a central nervous system that is also similar. At times, when EQ is taken into account, we have surprises. Neanderthals have bigger brains than Sapiens, but due to their massive bodies compared to the slender bodies of Sapiens, Neanderthals have an 11% cerebral deficit. I am not sure the 610 cm3 is correct if compared to the 465 cm3 because the difference between the two is widely more important in proportion than the difference between the minimum and maximum of Sapiens. We need to straighten up these measurements. If we consider the size, 143.6 cm compared to the average size of a Caucasian man, 177.4 cm, the difference is 33.8 cm, hence Naledi is 23.53% shorter (in his own terms) than a Caucasian Sapiens. But the weight, which is the mass of the body is 39.7 kg as compared to the average weight of an American Caucasian male of 89.6 kg, hence 49.9 kg in difference, and in Naledi's own terms a deficit of 125.7%. This means we should multiply the volume of the brain by (89.6 : 39.7 = 2.25). Hence the maximum brain volume is (610 x 2.25 = 1,372.50 cm3. This is no deficit at all. I am just surprised that Lee Berger did not take this EQ into account. The two calculations I made led to the same result. There is no cerebral deficit at all; even if we consider the average American Caucasian male weight of 89.6 kg is excessive within the comparison with Naledi's. I started using this EQ quotient some 15 years ago to compare Sapiens and Neanderthals. Nothing new then, in archaeology.

The frame and the longer thumb are just perfect for climbing, in trees of course, but also in caves. You have to take into account that the thumb is longer than ours because it is adapted to climb trees and grasp branches. That, of course, makes Naledi very good in the caves where he has to grasp rocks in order to climb up and down.

The pelvis and the trunk seem to imply Naledi is advanced in his bipedalism and has maybe moved one step further on the road leading to running.

But here the foot is not described properly. Similar means nothing. Homo Sapiens is unique among Hominins because the structure of his foot has completely been changed by his becoming a bipedal long-distance fast runner. From the picture given by Lee Berger, it is not conclusive whether Naledi is a walker or a runner. There is a lot of recent research on the problem of Homo Sapiens' foot and particularly its architecture and physiology for what is called endurance running, which I call bipedal long-distance fast running. Homo Sapiens does not run on the heel first but on the forefoot first with the midfoot arched ready to expand the forward movement of the whole body. The foot works like a sort of spring or diving board. See the figure below: Holowka, Nicholas B. & Lieberman, Daniel E., “Rethinking the evolution of the human foot: insights from experimental research,” published by The Company of Biologists Ltd | Journal of Experimental Biology (2018) 221, jeb174425, doi:10.1242/jeb.174425 © 2018

The point is to know if Naledi had the same arched midfoot as Homo Sapiens, and hence how far he was engaged in running, and if he had reached long-distance fast bipedal running, a stage in the evolution of Hominins that selected many mutations whose collateral side effect was oral articulated language. At the present level of research, it is impossible to say, though Naledi's foot seems to be only slightly arched.

The long legs must be compared to the full height of the body. But they can imply he is already entering the running stage, bipedal running, that often when trained early, at times very early, produces longer legs and this might not be genetic because it is the result of training, like pianists and their long fingers. This might also apply to the thumbs. That's one thing that has to be clarified in Naledi's lifestyle. Is he a simple walker or is he a runner? This requires some genetic mutations, and at the same time depends on the training the child, and even the infant gets.

The teeth are not specified in real size, and it is going to be the same as the brain. Smaller yes, maybe but multiply them by 2.25, and then look at the thus-obtained EQ size and compare it with Sapiens' teeth. It is standard to analyze dental tartar deposits on teeth to determine the diet of the person. Great advances were made in this field with Neanderthals and some even older Hominins. It is also used for animals. Such an approach might give better data on Naledi's diet. […]

Dr; Jacques COULARDEAU

Lien : https://jacquescoulardeau.me..