Chapter 11 Flashcards
Categorising humans
Homeo sapiens.
Humans belong to the family Hominidae + genus homo.
We are also mammals.
Taxas
Categorisation/classification to place species into similar categories - Arranged in hierarchical rank.
Mammals
Warm-blooded vertebrates belonging to the taxonomic class Mammalia.
eg. Dogs, Cats, Sheep, Pigs, Whales, Bears.
Key characteristics of mammals.
- Variety of teeth.
- 3 bones in the middle ear; aid hearing.
- 1 single lower jawbone.
- Various amounts of fur on bodies in a lifetime.
- Mammary gland; produces milk for offspring.
Primates
The highest order of mammals; 400 different species share features including opposable digits and binocular vision.
eg. Organutans, Lemurs, Gorillas, Baboons.
Primates key characteristics
- 3D colour vision + forward-facing binocular eyes.
- Large cranium relative to body weight.
- Flexible spine + large rotation.
- Prehensile hands.
- Sensitive touch receptors in fingerprints.
Hominoids
Members of the superfamily Hominoide.
eg. Great apes; orangutangs, chimpanzees, gorillas + humans.
Hominoids key characteristics
- Y5-shaped molar teeth,
- Broad ribcage.
- Large cranium.
- Long arms.
- No tail.
Hominins
Members of the taxonomic tribe Hominini.
eg. Modern humans + upright-walking ancestors.
Hominins key characteristics
- Bipedalism; using 2 legs for walking upright.
- Structural consequences from bipedalism; eg. broader rib cage, S-shaped spine.
- Communication + formation of complex social groups.
Hominin Evolution.
- Brain sizes increased; higher cognitive processes; planning, speech + abstract teaching. Evidence was found in the increased cranial capacity in fossil skulls.
- Shorter arms; increased reliance on bipedal locomotion.
- Longer legs; make walking upright more efficient.
- Changes to pelvis size; Shorter + more bow-shaped to support upper body. Also the demand for childbirth; more circular birth canal + narrowing pelvis.
Structural differences between us and our early ancestors.
- More centralised foramen magnum.
- Shrinking of sagittal crest.
- Lessening of brow ridge.
- Flattening of face.
- Less protruding chin.
- More domed skull.
- Smaller teeth.
Difficulties interpreting the evolutionary history
The fossil record is far from complete.
- Not all individuals die in conditions that promote fossilisation.
- Rock layers disappear.
- Rock layers are inaccessible; not all fossils are found.
Did we interbreed with neanderthals?
Hypothesis:
- Early humans interbred with neanderthals.
mtDNA suggests separate species that share a common ancestor
Neanderthal characteristics
- Wider nose.
- Shorter limbs.
- Stockier build.
- Flared rib cage.
- Sloping forehead.
- Enlarged brow ridge.
- Larger cranial capacity.
- Better resistance to cold climates.
New hominin species:
Homo Denisova; Closely related to Neanderthals; interbred from Melanesia.
Homo luzonensis; Small-bodied hominin ancestor with mixed ancient and modern human traits.
How Homeo sapiens spread
They first evolved in Africa 4mya.
2-2.25my later they migrated into Europe + Asia.
2 Main hypothesis:
- Out of Africa.
- Multiregional hypothesis.
Out of Africa
(More evidence)
- Humans first developed/evolved in Africa, before migrating outwards and expanding their colonies, replacing earlier hominins that spread prior.
Multiregional hypothesis
(Limited evidence)
- Separate human populations evolved independently from earlier hominins that had spread Eurasia and experienced gene flow.
Aboriginals’ connection to the country
Fundamental to identity.
Country is the reciprocal relationship between individuals and ancestral lands.
- The land provides for the people and the people sustain the land.
- Kinship of country.
- The dreaming; children’s spirits in the landscape.
Out of Africa approach diminishes the traditional viewpoint of first nation communities.
