Embryogeny and Phylogeny of the Human Posture 2. Anne Dambricourt Malasse

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Название Embryogeny and Phylogeny of the Human Posture 2
Автор произведения Anne Dambricourt Malasse
Жанр Биология
Серия
Издательство Биология
Год выпуска 0
isbn 9781119887775



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This organ was the central nervous system with the development of cognitive abilities. In other words, the guiding thread was encephalization. Obviously, the reference is Homo sapiens, which did not have specialized subspecies, but a plasticity adaptive to all environments, including the most extreme in latitude, altitude and depth. Sapiens did not need wings, fins or gills, it compensated with its technical intelligence. Later, Teilhard would be surprised to note that the cranial globular shape of the tarsier did not correspond to an encephalization, because the cerebral hemispheres were as smooth as those of a Strepsirrhini. In reality, this shape was not due to the brain but to the exuberant lateral extension of the orbits. His hypothesis of a third Eocene phylum prompted him to conceive of a simiiforme lineage as early as the Eocene (thus before the Oligocene, which saw the appearance of simians or monkeys):

      If, even before the Oligocene, the group of Tarsiers, which seems to be interposed between the Lemurs and the Simians, was approaching maturity, it must be assumed that, from that time on, the group of the superior primates1 was in full growth. This gives depth to our views on the group to which we belong: a Tarsier found, almost entirely formed, in the Phosphorites may mean that, somewhere on Earth, at that same time, Anthropoids were already sketched out [...]. They come, independently of each other, from a still unknown group of very small animals with a large brain which must have lived in the Paleocene, or even an earlier epoch. (Teilhard de Chardin, Sur l’origine tarsienne de l’Homme, 1921, author’s translation)

      The theory of a Paleocene simiiforme phylum has never been corroborated.

      Teilhard’s paleontological study nevertheless marked a major milestone in paleoprimatology, and the American George Gaylord Simpson (1902–1984), one of the great figures of 20th century in paleontology, paid tribute to him by giving his name, Teilhardina, to the oldest fossils of primates that lived in Asia, Europe and North America, from the Upper Paleocene to the Lower Eocene (between 56 and 47 million years ago). Today, the oldest primates are dated to 55 million years and were discovered in central China in 2003 in Hubei and in 2004 in Hunan. The fossils are kept at the Institute of Vertebrate Paleontology and Paleoanthropology of China, in Beijing. The first fossil from Hubei is an almost complete skeleton of very small size (7 cm and 20 cm with the tail) named Archicebus achilles (Ni et al. 2004). The orbits are small and the appendicular skeleton is that of an arboreal primate. The second fossil Teilhardina asiatica from Hunan has preserved only fragments of the skull and mandible.

      As long as the chordal skeleton is not straightened and since locomotion is not the mechanical cause of straightening, these locomotor adaptations do not allow us to speak of simiiforme features. It is the simians, characterized by the straightened embryonic cord, that have inherited these arboreal characters. It would be interesting to compare the axial endoskeleton of Archicebus with the current species of Loris in Southeast Asia. The last study in 2019 confirms, using dental characteristics, the distinction between these two Chinese fossils (Morse et al. 2019).

      Pierre Teilhard de Chardin defended his thesis entitled “Les mammifères éocènes inférieurs français et leurs gisements” (“French Lower Eocene mammals and their deposits”), which earned him international renown, at the Sorbonne University in April 1922. He was 41 years old and received the prize of the Société géologique de France (Geological Society of France) and the Roux prize of the Académie des sciences. He was elected President of the Société Géologique de France in 1926.

      Marcellin Boule wanted Teilhard to meet the holder of the chair of Mineralogy at the Catholic Institute of Paris, where higher education in the sciences was still poorly developed. It was important that natural sciences and evolution be taught in private establishments run by the clergy. Father Gaudefroy offered him the chair of Geology, pending the nomination of a professor; Teilhard accepted and became a lecturer. He taught geology there from 1920, defended his thesis at the Sorbonne in 1922, and was finally appointed Assistant Professor of Geology and Paleontology at the Institut Catholique de Paris. Teilhard de Chardin was therefore a professor and continued his teaching during the 1922/1923 academic year, while in agreement with the Society of Jesus, he devoted himself to paleontology in the basement of the Muséum’s gallery and participated in international conferences.

      This intelligibility of an earthly planetology approached as a growing living organism is already perceptible from the earliest years of his teaching. In 1921, Teilhard published the beginnings of his evolutionary thought in an article for the Études2, “How is the question of Transformism posed today?”: