1. Human Evolution - Anthropology
APS – Unit 1
Human Evolution - Anthropology

2. Evolutionary Theory Charles Darwin 1809-1882
Published Origin of the Species (1859)
Galapagos Islands – observed 2 species of finches
Controversial !

4. Darwin’s Theory – Natural Selection
Heritability: Organisms inherit characteristics from their parents
Variation: there is a lot of variation within a species
Environmental Fitness: Those traits that allow an individual to survive to reproductive age – to pass on to offspring

5. Darwin’s Finches
An example of Variation

6. Peppered Moth UK – example of natural selection
White and Black moths (Variation)
Food source for birds
Before Industrial Rev. most moths – white - better camouflaged against white lichen (Enviro. Fitness)
Industrial Rev – coal dust turned environment black, now black moths better camouflaged. Black moths now surviving to reproduce and pass their colour to next generation (heritability)
Now, most moths are black (natural selection)

7. Evolution – evidence Physical Anthropologists Look at:
1. Fossil, bone, stone remains (using dating techniques)
2. Microscopic analysis – pollen, scratches on bone
3. Experiments – flake stone techniques

8. Human Evolution

10. Human Evolution
hominid: is any member of the biological family Hominidae (the "great apes"), including the extinct and extant human chimps, bonobos, gorillas and orangutans

11. Hominids

12. Habitual Bipedalism
Bipedalism – to habitually walk on two legs. Humans only primate with this adaptation
What had to happen for us to stand up straight?

13. Bipedalism continued
Structural changes required for us to walk upright:
S-shaped spine
Double arched foot
Pelvis – shorter and wider
More gluteus muscles
Fewer head / neck muscles – therefore a bigger brain

14. Advantages of being bipedal
Free hands for carrying
Can walk longer distances
Can have a continuous good view of surroundings

15. Disadvantages of being bipedal
Highly dangerous birthing process
Offspring very dependent and weak because the skull must grow outside of the womb

16. Why Bipedal – Theories! Carrying – young, food, over long distances
Display – seem more impressive, scare predators
Trench Coat – males who display genitals attract mates
Energy efficiency – less area exposed to sunlight, cooler
Scavenging – carry food and tools away from exposed areas
Adaptability – gives more flexibility of movement and the means to adapt more quickly to changing situations.
Habitat – a chance to safely migrate out of the trees

17. Hominids and Brain Size
Humans have the largest brain for our body mass compared to other mammals

18. Hominid (human), Primate differences:
Primates
Hominids / Humans
Social structures
Dominance Hierarchies
Silverbacks and alpha males in a group
Grooming
Related to the hierarchies
Stress release
Pair Bonding AND Group Living
Humans are the only primates to have both social characteristics simultaneously

19. Hominid (human), Primate differences
Primates
Hominids / Humans
Reproduction
Estrus cycle (in heat)
No choice of when to mate
Who gets to mate when ties into dominance and grooming hierarchies
No estrus cycle
Choice in when to mate

20. Hominid (human), Primate differences
Primates
Hominids / Humans
Mother – Infant relationship
Long infant dependency
compared to other mammals
Important in learning survival skills and culture
Longest infant dependency
period of all primates

21. Hominid (human), Primate differences
Primates
Hominids / Humans
Communication
Facial displays, call, touch
Speech centre in the brain

22. Humanity and our Variations
Our bodies are essentially years old.
Now culture, not physical evolution enables us to adapt very quickly to a changing environment
Race - Cultural construct – does not physically exist

23. Skin Colour - Legitimate Explanations for Human Variation
Sunlight is the best source of vitamin D (necessary for healthy bones)
Light skin absorbs vitamin D and burns more easily than darker skin Paler skin is found in areas further from the equator where there is less sunlight (environmental Fitness)
Skin colour (variation)

24. Skin Colour - Legitimate Explanations for Human Variation
Darker skin provides better protection from UV rays
Darker skin is found in areas closer to the equator where there is more and stronger sunlight (environmental Fitness)
Skin colour (variation)