Demonstrate understanding of trends in human evolution
What this domain tests
This domain assesses trends in human evolution. You need to interpret anatomical evidence for bipedalism, encephalisation, reduced dentition and tool use, and explain the relationships among hominin species.
Core rules and concepts
- Bipedalism: forward-positioned foramen magnum, bowl-shaped pelvis, angled femur, arched foot. It appeared before large brains.
- Encephalisation: increase in brain size relative to body size; cranial capacity increases from Australopithecus to Homo.
- Dentition: reduced canine and jaw size, smaller molars, and a more parabolic dental arcade.
- Tool use and culture: Oldowan tools with Homo habilis, Acheulean tools with Homo erectus, complex tools and art with Homo sapiens.
- Key species: Australopithecus afarensis (bipedal, small brain), Homo habilis (early tool use), Homo erectus (larger brain, long-distance dispersal), Homo neanderthalensis (robust, cold-adapted), Homo sapiens (modern anatomy).
- Evidence supports an African origin and interbreeding with Neanderthals and Denisovans.
Worked example
A fossil skull has a foramen magnum positioned centrally under the skull, a broad short pelvis, and a femur angled inwards. These features indicate habitual bipedalism. If cranial capacity is about 450 cm3, it is more like Australopithecus than Homo. The reasoning links anatomy to function: a central foramen magnum balances the head on an upright spine; a bowl pelvis supports abdominal organs during walking.
Traps that cost marks
Presenting evolution as a linear chain; saying a species is more evolved; using brain size alone; confusing foramen magnum position with brain size.