Lecture 13- Human evolution Flashcards
Describe the evolutionary tree leading to humans…
- primates
- Spilt into 4 groups of Prosimians, Neotropic monkeys, Hominoids and old world monkeys
- Hominoids diverges into two groups
- First group is the orangutans and Gibbons from south east Asia
- The second group is the Gorillas, chimpanzees and hominins from Africa
- Humans are in the hominin group
When did the division into the SE Asia group and African group occur?
7 million years ago
What does diverge mean?
The creatures that became gorillas, chimpanzees and humans once came from the same group (have common ancestor). It does not mean that humans used to be gorillas.
What are the features of Ardipithecus Ramidus (Ardi)? How long ago did they live?
- Starting bipedalism
- Smaller canines
- Still long arms (associated with tree climbing)
- Small brain
-Lived 4.5 to 5 million years ago
What are the features of Australopithecus afarensis
(Lucy)? How long ago did they live?
- More upright in the hip but the head wasn’t directly above shoulders yet
- Stone tools for butchery
- Brain still small.
-Lived 3 million years ago
What are the features of Paranthropus? How long ago did they live?
- Big jaws for chewing tough stuff
- Lived around 2.3 to 2.6 million years ago roughly
What are the features of Homo erectus? How long ago did they live?
- Fully upright, with forward facing feet +toes specialized for running and walking on two legs
- Some stone tool use
- Lived across the Old World;
- Brain grown from 750 cc to 1,000 cc (large increase)
Across all hominin species what is the most important trend displayed?
Increase in brain size up to 1,250 cc
What happened to H. erectus? Are humans in placed other the Africa direct descendants from them?
If H. erectus was spread across the old world you might assume that they evolved into homo sapiens simultaneously across the world
-This is not the case instead they died off and H. Sapiens spread from Africa to replace the older species
What happened in regards to the population bottle neck? When did this occur?
- Genetic reduction in diversity as only the species in eastern Africa survived
- Migration from eastern Africa replaced previous peoples.
- Possibly due to Lake Toba Supervolcano
-Happened around 7 million years ago
Where and when did the species that invented language exist?
- Sub-saharan Africa (eastern and southern)
- 100K-60K ago
How did tools evolve over time to become more complex?
- 2 million years ago= Oldowan tools which were hand held rocks that have been sharpened on one side
- 500 thousand years ago= Achulean tools which were more finely shaped
- 100 thousand years ago= Stone blades, microliths, stone AND wood, points to spears
- 50 thousands years ago= Fish hooks, buttons, bone needles, jewelry, paintings
General trend as go on as get more variety and the tools are suited to a particular purpose/ finely crafted
How did hunting evolve over time?
- 2 millions years ago= passive scavenging.
- 800 thousand years ago= power scavenging
- Approx. 200 thousand years ago= hunting
What is power scavenging how is this different from hunting?
When you let other animals perform the kill and then come in and use tools to scavenger the meat off before the animal can eat it. Different to hunting where the tools were actually used to directly kill.
What was vital for complex hunting and scavenging?
Cooperation, as would work together to:
- Herd animals towards a waiting party or to surround
- Herd animals into mud or over a cliff
These techniques required planning and handing out different roles to people based on their strengths. In hunting also need to be able to predict what the other person will do and imagine possibilities.
