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Evolution of Humans

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Evolution of Humans
Marie ДЊernГЎ
Time scheme of Evolution
Precambrian era
4.0 billion
years ago
4.6 billion
years ago
2.5 billion
years ago
3.5 billion
years ago
1.5 billion
years ago
multicellular eukaryotes
(prokaryotes) unicellular eukaryotes
Time scheme of Evolution
• Paleozoic era (supercontinent Pangea)
500 million y. a. – plants, fungi, animals
colonize land (Cambrian period)
• Mesozoic era = “Dinosaurs period”
250 million y. a. – first mammals
• Cenozoic era (after extinction of dinosaurs)
50 million y. a. – majority of mammals
5 million y. a. – diversion of humans and apes
Time scheme of Human Evolution
Homo ergaster
Time scheme of Human
• 35 million years ago – dawn ape:
anthropoid Aegyptopithecus
• 5-7 million years ago - diversion of humans and apes
from the common ancestor
• 4 million years ago – ape-man: Australopithecus
• 2.4 million years ago – handy man: Homo habilis
• 1.9 million years ago – working man: Homo ergaster
• 1.8 million years ago – upright man: Homo erectus
• 0.5 million years ago – archaic Homo sapiens
0.2-0.03 million years ago – Homo neanderthalensis
• 0.2 million years ago – Homo sapiens
Important Characters
of Human Evolution
• Size of brain
Australopithecus 400cm3 =пѓ� Homo sapiens 1 300cm3
• Shape of jawbone - shorter and reduced jawbone
=пѓ� flat face, chin protrusion, change of dentition
• Upright bearing, bipedal locomotion → skeleton
• Reduced sexual dimorphism
higher weight of male than female: gorilla 2x =пѓ� human 1,2x
• Changes in social life
monogamy with long-term pair-bonding – longer care of the
young allows better learning and complex behaviour formula
Three Models for the Origin of Humans
• Multiregional model – Modern humans evolved in
many parts of the world from regional descendants of
Homo erectus, who dispersed from Africa between 1
and 2 million years ago.
• Monogenesis model (“out of Africa” model) – Only
the African descendants of Homo erectus, who
dispersed from Africa just 0.1 million years ago, gave
rise to all the diverse populations of modern humans. All
other regional descendants of Homo erectus, including
Neanderthals, became extinct without contributing to the
gene pool of modern humanity.
• Intermediate model - Modern humans may be the result
of a migration out of Africa as well as some genetic
contribution from non-African archaic groups.
Multiregional Model
for the Origin of Humans
1-2 million years ago
Monogenesis Model
for the Origin of Humans
100 000 years ago
Proof for Monogenesis Model:
• mitochondrial DNA divergence
• greater genetic diversity within African
• studies of DNA from the Y chromosome
Three Major Stages of
Cultural Evolution
• The first stage began with nomads who hunted and gathered food on
the African grasslands 2 million years ago. They made tools, organized
communal activities, and divided labor.
• The second stage came with the development of agriculture in Africa,
Eurasia, and the Americas about 10 000 - 15 000 years ago. Along with
agriculture came permanent settlements and the first cities.
• The third stage was the Industrial Revolution, which began in the 18th
– Through all this cultural evolution we have not changed biologically in any
significant way.
– Our know-how is stored not in our genes but in the cumulative product of
hundreds of generations of human experience, passed along by parents,
teachers, books, and, most recently, by electronic means.
Biology, eighth edition,
Campbell, Reece
Unit five: The Evolutionary History
of Biological Diversity
Chapter 34: Vertebrates
Concept 34.8: Humans are mammals that
have a large brain and bipedal locomotion
Pages 728 – 733
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