Human Evolution Flashcards
Biological Evolution
Change in allele frequencies over time.
Cultural Evolution
Change in knowledge - the transmission of ideas.
Bipedalism
Walking habitually on two legs.
Advantages of Bipedalism
Being taller (see further to look for food and predators)
Thermoregulation (being upright means less surface area for sun to hit plus more air to circulate, allowing better cooling)
Sexual display (possibly allowing sex organs to be displayed allowing reproductive success)
Energy saving (although walking on two legs isn’t faster than four, it is slightly more energy efficient, especially over long distances)
Foramen Magnum in Bipedalism
Hole in base of skull where the neck where the spine enters has become more centralised, allowing the skull to balance in line above body/feet.
Saggital Crest in Bipedalism
Saggital crest (along the top of the skull), which serves as an attachment for masseter (chewing) muscles is usually absent.
Nuchal Crest in Bipedalism
Nuchal muscles (located at the back of the skull and keep the skull upright, where neck muscles attach) is much smaller and is further down - less muscles are needed for head to be held above body and facing forward.
Zygomatic Arch in Bipedalism
Zygomatic arches do not flare out to accomodate for larger masseter muscles, means face is narrower as opposed to wider.
Brow Ridge in Bipedalism
Trend towards no brow ridge.
Valgus Angle
Head of femur (hip joint) is wider than knees, femur is thus angled inwards (valgus angle). Quadrupeds don’t have a valgus angle.
Endocranial
Increased brain size - 1400cc as opposed to 400cc.
Fully opposable thumb
Thumb is longer and more mobile than quadrupeds. Increased dexterity in thumb joints and ligaments.
Cerebellum
Increased specialisation of the cerebellum: finer muscle coordination and balance.
Cerebrum
Increased specialisation of the cerebrum: complex processing, problem solving.
Broccas Area
Increased specialisation of the broccas area: sound sequencing and production.
Wernickes Area
Increased specialisation of the wernickes area: sound processing and interpretation.
Precision Grip
Precision grip and fine manipulation possible because thumb is longer and has very sensitive pads.
Oldowan Tool Culture
Used by….
Made by….
Advantage….
How long ago….
Used by the Homohabilis.
Made from river worn pebbles. A minimum number of flakes were knocked off from several angles to produce a core with a cutting edge.
Advantage: gave access to bone marrow.
3 million years ago.
Achuelean Tool Culture
Used by….
Made by….
Advantage….
How long ago….
Used by Homoerectus.
Tear drop shaped and crafted with a slight bulge on each broad surface. Hand axe. Each tool is manufactured using many more blows than Oldowan tools to remove flakes.
Advantage: ceremonial, monetary use. Butchering large animals, milling branches or trees into fire fuel.
2 million years ago.
Mousterian Tool Culture
Used by….
Made by….
Advantage….
How long ago….
Used by Neanderthals.
Flint was commonly used. This stone would chip in a predictable way when struck with another hard object so finer workmanship was possible. The Levallois technique was used. It involves the preparation of a core and striking off a large oval flake which is then retouched on one surface only.
Advantage: Involved fire, improved hunting, more materials, flint.
About 1.5 million years ago.
Upper Palaeolithic Tool Culture
Used by….
Made by….
Advantage….
How long ago….
Used by Homosapiens.
Punch blade technique. Long thin flakes are removed and shaped into different tool types.
Advantage: clothing, fishing.
About 35,000 - 40,000 years ago.
Advantages of being able to control fire.
Provides heat and light.
Light allows for more hours in the day to be used productively.
Warmth allows hominins to move to colder areas, increasing the range in which they can travel.
Fire can be used in hunting and scaring off predators.
Can be used to improve tool quality.
Food can be cooked - softer food. Strong, large jaw muscles and large molars are no longer selected for.
A greater variety of foods can be eaten, adding to the quality of diet.
Importantly fire allowed a gathering place for sitting around and sharing ideas.
Scavenger
Scavengers are animals that consume dead organisms that have died from causes other than predation.
Hunter/gatherer
A hunter-gatherer is a human living in a society in which most or all food is obtained by foraging.
