Article 36: The genus ‘Homo’ is the youngest twig from a 2.5 million year old branch from a 4.6 billion year old tree, a seedling in a 13.8 billion year old universe. You and I are a recent leaf, or maybe a flower, on that twig!
The Pleistocene Period of the Earth’s history sees the evolution and expansion of our own species, Homo sapiens.
At first appear the hominoidae, next the hominidae, homininae, hominini and the hominina … and there we are: homo! Let us meet our family!
Humans in order of appearance:
The earliest members of the genus Homo are Homo habilis, which evolve around 2,8 million years ago. Homo habilis is the first species for which there is clear evidence of the use of stone tools. The brains of these early hominins are about the same size as that of a chimpanzee. Their main adaptation is bipedalism as an adaptation to terrestrial living. During the next million years a process of encephalization begins. With the arrival of Homo erectus in the fossil record, cranial capacity doubles.
In 1871 Charles Darwin will write in his book “The Descent of Man”:
”No one, I presume, doubts that the large proportion which the size of man’s brain bears to his body, compared to the same proportion in the gorilla or orang-oetan, is closely connected with his mental powers.”
Homo erectus is the first of the hominina to leave Africa. He spreads his wings through Africa, Asia and Europe between 1,8 to 1,3 million years ago.
One population of Homo erectus stays in Africa and evolves into Homo sapiens. It is believed that these species is the first to use fire and complex tools.
Anatomically modern humans appear from about 200.000 years ago. Around 50.000 BP (Before Present) full behavioral modernity, including language, music and other cultural universals, has developed.
Around 74.000 years ago, the Toba super-volcano erupts on the island of Sumatra, ejecting a giant ash cloud that blocks out the sun and severely affects food supply. It has been suggested that this contributes to the near collapse of the human population around that time.
After the Toba catastrophe, the modern humans gradually marginalize the “archaic” varieties. These non-modern varieties of Homo are certain to have survived until about 30.000 years ago. Which of these, if any, are included under the term “archaic human”, is a matter of definition and varies among authors. Nonetheless, according to recent genetic studies, modern humans may have bred with “at least two groups” of ancient humans: Neanderthals and Denisovans. Recent studies of the Human and Neanderthal genomes suggest gene flow between archaic Homo sapiens and Neanderthals and Denisovans, in which case these earlier populations may have contributed genetic material to modern humans. Maybe they did so to you too! Interested? Join the more than 700.000 people who have already taken part in National Geographic’s groundbreaking Genographic Project and buy yourself the Geno 2.0 Next Generation DNA Test kit!
The dispersal of Homo sapiens out of Africa, walked nowadays by Paul Salopek, is estimated to begin from North-East Africa, about 70.000 years BP, give or take a few weeks. Current evidence suggests that there is only one such dispersal and that it only involves a few hundred individuals. The vast majority of modern humans stays in Africa and adapts to a diverse array of environments. Modern humans subsequently spread globally, replacing earlier hominins, either through competition or hybridization. They inhabit Eurasia and Oceania by 40.000 years BP and the Americas at least 14.500 years BP.
Until circa 12.000 years ago, humans live as hunter-gatherers. They generally live in small nomadic groups, known as band societies.
A band society is the simplest form of human society. A band generally consists of a small kin group, no larger than an extended family or clan. One definition sees a band as consisting of no more than 100 individuals. The advent of agriculture prompts the Agricultural Revolution, when access to food surplus leads to the formation of permanent human settlements, the domestication of animals and the use of metal tools for the first time in history. Agriculture encourages trade and cooperation and leads to complex societies. Because of the significance of this date for human society, it is the epoch of the Holocene calendar or the Human Era. A wonderful book about this period is Guns, Germs and Steel: The Fates of Human Societies, by Jared Diamond. Diamond argues that the gaps in power and technology between human societies originate in environmental differences.
We have looked at our past, but what about our potential, our imprisoned splendor, our future maybe, represented here by a couple of fellows who may have brought this splendor into expression:
“If you think
man now is the end product,
then you will feel,
like the existentialists,
that man is meaningless,
a tale told by an idiot.
But if you can look in the potentiality,
then suddenly, man is not diseased,
rather on the contrary,
nature is trying to reach a higher point,
the greatest yet attained –
evolution working in man.”
Thanks to the University of California, Berkeley, Museum of Paleontology
Quote by Osho from Just Like That, Ch 3