Chapter 2. Phylogenetic aspects of OA

The most difficult question that a researcher of any historical phenomenon poses to himself is from what period to start studying it.

So... 3.6 million years ago, two Australopithecus left footprints in the volcanic ash in Northern Tanzania, 20 km from the Sadiman volcano (Fig. 2.1). The Laetoli Area is unique in that there are no traces of flooding or dense Equatorial forests on its territory, and for this reason, the climate, landscape, and ecosystem remain unchanged for several million years.

Fig. 2.1. «Famous» traces of early hominids in Tanzania, discovered in 1978

This is how paleoanthropologist Donald Johanson described this prehistoric event in his book «Lucy. The origins of the human race» (Fig. 2.2-2.3). «An incredible combination of random circumstances led to the fact that the traces still remained: Sadiman threw ash of a certain type, followed by rain. Then the hominids walked over the layer of wet ash, and the sun quickly dried their footprints.

Soon there was another eruption of Sadiman, and the tracks were covered with a new layer of ash, which protected them from another downpour…»

Fig. 2.2. «Lucy» — the most «Famous» Australopithecus. Fossils of a female, only 1.2 m tall, dated to about 20 years old, belong to the species Australopithecus afarensis. This hominid that lived 3.3 million years ago is considered a «link»

Fig. 2.3. Donald Carl Johanson (born 1943) — paleoanthropologist, USA. Discovered the skeleton of Australopithecus «Lucy» in Ethiopia on November 24, 1974

It is obvious that the probability of preserving traces in Laetoli was minimal. The prints found confirmed with absolute certainty what Lucy’s discovery has already told the world: three million years ago, if not earlier, hominids were already moving freely on two legs». In the quote, Sadiman is mentioned.

Archaeology is no less controversial than modern arthrology, and there are different opinions on the same phenomena, often opposed. A group of specialists in the field of Mineralogy, led by A.N. Zaitsev, «doubted» the identity of the chemical composition of the tufa (2,4,5-Trihydroxyphenylalanine) in which traces of hominids and volcanic rock from the volcano were found, however, at present, a unique trail, recognized as the earliest monument to humanity, is available for tourists to view. Also note that according to some data, the number of individuals who left traces was 3, probably two adults and a child.

At first glance, the evolution of hominids has little in common, both with modern medicine and with the issue under consideration, in particular, because the early hominids were a different species and their way of life was radically different from ours.

In the context of the problem under consideration, we will not analyze the intraspecific and interspecific relationships of early hominids-we will leave this for paleogenetics. We are more interested in the biomechanical relationships of lower limb segments in the Australopithecus — Neander­thal — Cro-Magnon vector. Despite the fact that most Australopithecines and Neanderthals, according to recent data, are not considered direct predecessors of modern man, but rather dead-end branches of evolution, they are most interesting from the point of view of analyzing the signs of erect walking and its consequences in the form of degenerative pathology.

Meanwhile, archaeologists in cooperation with paleopathologists have long concluded that the degenerative pathology of the spine and large joints is based on the transition to upright walking. Skeletal tissue is the evidence from the past that archaeologists have used to reconstruct a key period in the phylogeny of early hominids. The possibility of preserving soft tissues is theoretically possible, for example in mammoths in permafrost, but it is believed that the ancestors of Homo Sapiens lived in hot and humid climates. Therefore, soft tissues are studied by indirect signs, again in accordance with their effect on bone structures.

Fig. 2.4. The skeletons of chimpanzees, Australopithecus, and H. Sapiens show an increase in height and a change in the proportions of the lower limbs

Fig. 2.5. Diagram of human and early hominid phylogeny

In particular, archaeologists suggest that the intestines of early hominids were significantly longer than ours due to the predominance of raw fiber in the diet and this affected the chest aperture.

Undoubtedly, paleogenetics opened up unique opportunities and the analysis of nucleotide sequences revealed the presence of up to 2% of Neanderthal DNA in human DNA, which geneticists associate with the possibility of cross-breeding.

Fig. 2.6. Foot of chimpanzee — a, Australopithecus — b, human — c

Fig. 2.7. Caricatures of Charles Darwin from 1859 to the present day — one of the independent trends in the visual arts

Even this caricature shows a fundamental difference in the structure of the monkey’s foot-the opposition of the thumb is possible. The brush differs much less.

As we moved up the evolutionary ladder, the traditions of burying the dead were also formed, which reached «perfection» among Neanderthals — initially as a privilege, then it became accessible to the common population, which allows skeletal tissues to transform into an inorganic matrix while preserving the anatomical structure, thereby becoming the object of research.