1. David Sadava H. Craig Heller Gordon H. Orians William K. Purves David M. Hillis Biologia.blu B – Le basi molecolari della vita e dell’evoluzione The Evolution of the Human Species

2. Who were the first humans? When and where did they live?
The Evolution of the Human Species
Who were the first humans?
When and where did they live?
What makes us human?

3. The Evolution of the Human Species - Who were the first humans?
Human appearance on Earth

4. Domain Eukaryota Kingdom Animalia Phylum Chordata Subphylum Vertebrata
The Evolution of the Human Species - Who were the first humans?
Human taxonomy
Domain
Eukaryota
Kingdom
Animalia
Phylum
Chordata
Subphylum
Vertebrata
Class
Mammalia
Order
Primates
Superfamily
Hominoidea
Family
Hominidae
Genus
Homo
Species
Homo sapiens
Subspecies
Homo sapiens sapiens 4

5. Digit mobility (grasping and opposability) Optical shift Bipedalims
The Evolution of the Human Species - Who were the first humans?
Primate evolutionary trends
Digit mobility (grasping and opposability)
Optical shift
Bipedalims
Relative size of the cerebral cortex
Parental care 5

6. The Evolution of the Human Species - Who were the first humans?
Close relatives
Human species and anthropomorphic apes (gorilla, gibbon, orangutan, chimpanzee) belong to the superfamily of the Hominoidea, primates without tails. 6

7. The Evolution of the Human Species - What makes us humans?
Hominidae characteristics
The spine meets the skull, balancing the head in a vertical position
The face is straight
The spine meets the skull in the back
The face shows a relative degree of prognation
Quadrupedal gait
(knuckle-walking)
Bipedal gait
(man is truly vertical)
Opposability of big toe
Non-opposability of big toe
Plantar arch missing
Plantar arch and a more robust calcaneus
Short pelvis allows bipedalism
Femoral shaft angle,(feet directly below the center of gravity)
Femur
almost vertical within a horizontal plane 7

8. The Evolution of the Human Species - Where did the first humans live?
A common ancestor
Different climates in the two areas of the Eastern African Rift Valley are thought to have caused the evolutionary divergence between Hominidae and anthropomorphic apes.pes
Atlantic ocean
Indian ocean 8

9. Brain size grew larger (genus Homo)
The Evolution of the Human Species - Who were the first humans?
Early hominid characteristics
Bipedalism
Brain size grew larger (genus Homo)
Reduction of sexual dimorphism (Homo erectus) 9

10. Mean cranial capacity (cm3)
The Evolution of the Human Species - When did the first humans live?
Species
Date
(thousand years)
Body weight
(kg)
Mean cranial capacity (cm3)
Cephalic index*
Homo s. sapiens
To present 58
1349
5.3
Homo sapiens
35-10 65
1492
5.4
Homo neandertaliensis
75-35 76
1498
4.8
Late Homo erectus 68
1090
3.8
Early Homo erectus 60
885
3.4
Homo habilis 42
631
3.3
Australopithecus africanus 36
470
2.7
Australopithecus afarensis 37
420
2.4
Chimpanzee 45
395
2.0
Gorilla
105
505
1.7
*ratio of the maximum width of the head multiplied by 100 divided by its maximum length
The first members of the genus Homo appeared around 2.5 million years in Africa. 10

11. The Evolution of the Human Species - Who were the first humans?
Turkana Boy (Homo erectus)
Homo erectus is generally considered to have been the first species to have expanded beyond Africa, and related fossils are spread over two continents.
A nearly complete 1.6-million-year-old skeleton, found near Lake Turkana, Kenya, belonged to an eight-year-old boy. 11

12. The Evolution of the Human Species - Who were the first humans?
Professor Svante Pääbo holding the skull of a Homo neandertaliensis
An international consortium of researchers has sequenced the genome of our closest relative, the Neandertal. Results indicate that Neandertals are slightly more closely related to modern humans outside Africa. The team also identified several genomic regions that appear to have played an important role during human evolution.
(Science on May 7, 2010) 12

13. The Evolution of the Human Species - What makes us humans?
Two possible models
Out-of-Africa model
Multiregional model
Europe Africa Asia
Europe Africa Asia
(present)
Interbreeding between people living in Europe, Asia, and Africa (gene flow)
Homo sapiens evolved from Homo erectus in Africa
0.5 million
years ago
Modern humans evolved more or less simultaneously in all major regions of the Old World from local archaic humans.
Humans with modern traits left Africa from 50,000 to 60,000 years ago to settle the world
(1.8 million years ago) 13 13

14. Worked stone tools Evolution of language Cave art, burials
The Evolution of the Human Species - What makes us humans?
Cultural evolution
Worked stone tools
Evolution of language
Cave art, burials
Domestic animals
and agriculture 14 14