7. The Evolution of Hominids

7.0 Introduction

The geneticist Theodosius Dobzhansky published in 19371 his concept about the origin of Species. The views of the ornithologist Ernst Mayr followed in 19422. The paleontologist George Sympson contributed his own ideas3. These three views were synthesized into the concept … Continue reading

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7.1 The first hominids

The extensive ice deposits that began to appear six million years ago on the poles lowered substantially the level of the seas, dried up part of the earth and erased plant life in many regions. When the ice melted, the … Continue reading

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7.2 The Australopithecines

Abundant remains of 5 different species of Australopithecines are found in Pliocene rocks all over East Africa, from Lesotho to Ethiopia. They are about 4.3 to 2.5 million years old. Remains of an Australopithecine species found at Hadar in Ethiopia … Continue reading

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7.3 Homo Habilis

Two million years ago, the chimp-sized brains of the early australopithecines almost doubled in a growth spurt. Homo habilis is characterized by a progressive reduction of the dental and facial apparatus and by the development of cranial capacities that led … Continue reading

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7.4 Homo Erectus

Homo erectus, the Pithecantrop, originated in Africa. Remains dating 1.8 million years, together with simple “Oldowan” stone tools, have been found in Tanzania (Olduvai Gorge). In Kenya (Turkana), a date of 1.9 million is plausible. This early species of H. … Continue reading

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7.5 Homo Sapiens Neanderthalensis

The refined Levalloisian culture that had appeared 150,000 years ago during the Riss glaciation (see fig. 7.6) was adopted and continued in the Near East and Europe by men appearing 100,000 years ago, during the Riss-Wurm interglaciary. Figure 7.6. Time … Continue reading

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7.6 Homo Sapiens Sapiens

There is nothing disproportionate about the frontal lobe in humans. Humans do have larger brains for their bodies than other primates but no particular section of the brain is swollen. All parts of the brain, except the cerebellum, scale up … Continue reading

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7.7 The expansion

7.7.1 Away from tropical lands Bony fishes synthesize vitamin D, which controls the uptake of calcium needed to build up bones. This synthesis is essential to avoid rickets. In amphibians, reptiles, birds and mammals, vitamin D is formed through exposure … Continue reading

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7.8 The biochemical basis of hominisation

For a long time, the paradigm of protein synthesis was: “one gene –one messenger RNA-one protein”. This concept was acquired by the study of prokaryotes, essentially Escherischia coli, a microbe colonizing the human intestinal tract. The discovery in 2001 that … Continue reading

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7.9 The Noosphere

Teilhard de Chardin, a Jesuit paleo-anthropologist, observed30 that we are so much immersed in the human phenomenon that during the whole of the 19th century, and most of the 20th, this phenomenon escaped scientific investigation. According to him, man is … Continue reading

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