Evolution of human Lecture No 530-V. „Nothing in biology makes sense except in the light of evolution.“ Theodosius Dobzhansky.

Evolution of human

Lecture No 530-V

„Nothing in biology makes sense except in the light of evolution.“

Theodosius Dobzhansky

Time scheme of EvolutionTime scheme of EvolutionPrecambrian eraPrecambrian era

4.6 billionyears ago

4.0 billionyears ago

3.5 billionyears ago

2.5 billionyears ago

1.5 billionyears ago

multicellular eukaryotes

unicellular eukaryotesprokaryotes

Time scheme of EvolutionTime scheme of Evolution

• Palaeozoic 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

Plate Tectonics Pangaea Continent Maps

Time scheme of Human Time scheme of Human EvolutionEvolution

• 35 million years ago – dawn ape:

anthropoid Aegyptopithecus• 5-7 million years ago - diversion of the common ancestor of

humans and apes • 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

0.2-0.3 million years ago – Homo neanderthalensis• 0.2 million years ago – Homo sapiens

Time scheme of Human EvolutionTime scheme of Human Evolution

Homo ergaster

skeleton (AL 288-1) Australopithecus afarensis, cast from Museum national d'histoire naturelle, Pari

The fossil Lucy

Important Characters of Human Evolution

• Size of brainAustralopithecus 400cm3 = Homo sapiens 1 300cm3

• Shape of jawbone - shorter and reduced jawbone

= flat face, chin protrusion, change of dentition

• Upright bearing, bipedal locomotion → skeleton

• Reduced sexual dimorphismhigher weight of male than female: gorilla 2x = human 1,2x

• Changes in social lifemonogamy with long-term pair-bonding – longer care of the young allows better learning and complex behaviour formula

Size of brain and shape of jawbone

Au. africanus, H. erectus & H. sapiens

Height and upright bearing

Reduced sexual dimorphism

Three Models for the Origin of Human

• 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.

Monogenesis ModelMonogenesis Modelfor the Origin of Humanfor the Origin of Human

100 000 years ago

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.

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.

Three Models for the Origin of Human

Multiregional Model Multiregional Model for the Origin of Humanfor the Origin of Human

1-2 million years ago

Proofs:• mitochondrial DNA divergence – greater

genetic diversity within African populations

• studies of DNA from the Y chromosome

• Recent DNA evidence suggests that several haplotypes of Neanderthal origin are present among all non-African populations

Mitochondrial Eve

Comparison of neutral mutations could

explain differences on possible

relationship between different human

populations.

Homo sapiens originated from a small

group of females (or only one female) –

such called „mitochondrial Eve“, which

delivered to us her mitochondrial genes.

„Eve“ lived in Africa. It supports the

hypothesis, that the whole mankind

originated from only one ancestor (i.e.

„out-of-Africa theory).

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, the Industrial Revolution, began in the 18th century.– 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.

Evolution of Human and Modern Medicine

Explanation of civilization diseases:

• Obesity• Immunity disorders – allergy

autoimmunity

tumors - leukemia

Primeval human• In close contact with nature• Frequent change of

dwelling• Exposed to frequent

infection stimuli

(infection the most frequent cause of death)

- Extreme physical activity

- Alternation of satiety period with starving period

Australopithecus afarensis

Homo erectus

Homo neanderthalensis

LiteratureLiterature

Biology, eighth edition,Neil A. Campbell, Jane B. ReecePearson International Edition, 2008

Unit five: The Evolutionary History of Biological DiversityChapter 34: Vertebrates: Humans are mammals that

have a large brain and bipedal locomotionpages 728 – 733

Thank you for your attention and have a fun with

the Croods or the Quest for fire