Human Evolution - 91606 Condensed Notes PDF

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Human Evolution - 91606

Quadruped: All four limbs

Bipedalism Background & Hominin Evolution Primate groups: I can name and identify the 5

Hominin groups: I can explain the niche of the different Hominin species.

different primate groups.

Prosimians (lemur) New world monkeys (spider monkey) Old world Monkeys (baboons) Great Apes (gorillas, chimpanzees, orangutans, and gibbons) Hominins (Afarnesis, Habilis, Erectus, Neander, Sapiens)

Hominins vs Hominids: I can differentiate the two groups.

The hominin group is a sup-group of the Hominid group. This subgroup consists of humans and their like ancestors who are habitually bipedal.

Homoheidelbergenisis: Species that lived around 300,000ya more advanced than Homoerectus. They are the hominin species between H. Erectus and H. Neanderthal.

A. Afarnesis: Includes the fossil Lucy, they lived 4-3mya. They are known as the first fully bipedal species. Their brain size was around 380-450cc. They had no tool culture. They had no communication either and moved around in groups. Homohabilis: They lived 2.4-1.5mya. The first hominin handymen using Oldowan tools (stone tools). They were also the first to have speech however it would have likely been grunts. They were able to hunt animals using the tools, increasing their protein intake thereby allowing for greater brain development (500-800cc). Homoerectus: They lives 1my-300,000ya known as the ‘upright man’. They were the first to use fire, they used the fire for various reasons. Firstly, for food, it made it safer as it killed bacteria to eat and easier to digest. Secondly, it provided a source of light and warmth allowing them to venture around Africa. They had greater tool development (Oldowan + Alcheulean), larger general population and more developed brain (8001100cc) compared to H. Habilis. Homoneanderthals: Lived around 230,000-28,000ya. They were relatively intelligent with a larger brain size then previous Hominin species (1200-1750cc). They also had some cultural practices such as burying the dead and performing rituals. They had advanced tools known as ‘Mousterian tools’ that served many purposes. They are expected to have likely lived in caves and wore animal hides as clothes. They interbred with Humans early according to DNA analysis. Homosapiens: The current hominin specie that dates back around 160,000 years ago. They have a relatively similar brain size to H. Neanderthal 1200-1700cc. Their tool culture consists of upper paleothic tools.

Biological Evolution: The transmittance of physical,

Cultural Evolution

Biped: Two limbs Skull: Foramen Magnum centrally located, places directly on top of the spine, requires less muscular energy to hold the head up. Small nuchal crest – where neck muscle attaches. Spine: S-shaped spine, this keeps the bodyweight above the hip joints Pelvis: Bowl-shape, which is short and wide, in order to reduce stress from standing upright from the upper body.

Pelvis: They have large leg muscles which are attached to the leg muscles meaning there needs to be a large surface area. Therefore, they have a long and narrow pelvis.

Femur: Valgus angle, an angle away from the midline. The femur is angled relative to the pelvis, it positions bodyweight through the pelvis when walking.

Femur: Short and stubby, hangs directly from the hip. Allowing for the swinging motion when moving from tree to tree.

Foot: Arched foot, acts as a shock absorber when walking and running, allowing us to walk relatively long distances. The forward-facing big toe helps provide forward thrust. Teeth + jaw: Small teeth and U-shaped jaw, small jaw muscles.

Foot: Flat foot with the big toe sticking out. The sticking out big toe allows for grip to grab things with their foot. They can use both hands and feet when swinging through tree to tree. They have flat feet as they don’t stand on their feet often.

Brow ridge: Thick, more prominent, allowed for chewing tough meats.

Ribcage: barrel shape/funnel shape.

Ribcage: flattened cone, flat front to back.

Teeth + jaw: Rectangular jaw, large jaw muscles and large teeth. Brow ridge: Small brow-ridge to avoid injury during scrimmage.

Advantages of bipedalism: Hands free: allows for tool making which can be used to cut up food that then can be cooked over fire. This changed out diet as bipedalist and this mean there was a change in our teeth and jaw. As well as brain development due to greater protein intake. Greater height: This allows them to locate predators, food, shelter and appear intimidating.

a major disadvantage to females during childbirth. Arch of foot not always developed leading to flat feet and therefore the ‘shock’

Display to others: Body appears larger thus more intimidating. Helped move up the food chain.

against gravity in an upright posture.

Cultural Evolution: The passing knowledge from one

Tools: Oldowan: Tools that were chipped on one side, sharp enough to cut meat and work through wood. Auchlean: Flattened hand axes, made by chipping off at either side. They were symmetrical and had

Fossil record: The fossil record can tell us when and where these organisms where from and what they may have looked like.

Exposure of land: Travellers

Fire: Killed microbes on meat that otherwise would

Mousterian: More carefully shaped and were often used with other materials i.e. stone arrowhead bout

make us sick. Softened food making it easier to digest. It enabled meat to become apart of our diet. It also enabled hominins to stay warm in winter months. Which eventually helped us venture out of Africa. It served as a source of light allowing hominins to have a longer period for social interactions, hunt and gather food and make tools. It also helped create tools as it hardened certain material. All these contribute to the growing rate of cultural evolution.

to wood to create a spear.

were able to venture the corners of the globe as there was more exposed land.

Palaeolithic: Made from multiple materials, stone, animals’ bones, plant fibres etc. This helped for the

Dispersal: Where hominin

creation of tents and clothes as there were nets, roped, and cutting tools.

species left Africa and ventured around the world.

Advantages & Disadvantages of farming: Advantages: Food supply, easier to obtain with much more dependable food source. Increased survival, less

Out of Africa theory: (Replacement model) Suggests that all homo sapiens originated in East Africa. DNA analysis shows that 1-3% of European DNA is “Neanderthal” DNA. This would have resulted from interbreeding between the homo sapiens and homo Neanderthals during a period of time and location. Africans are more genetically diverse than Asian and European populations. Indicating African population are much older than the Asian and European populations. Suggesting Homosapiens originated in Africa then left. Evidence is shown through fossils, the oldest homo sapiens fossils found outside of Africa are not as old suggesting the origin of Homo Sapiens in Africa. Multiregional theory: It suggests Homo sapiens evolved simultaneously in Africa, Asia, and Europe. DNA across all humans is similar however only African populations are more genetically diverse. This theory suggests that there is a lot more genetic variation. There is a few found transitional fossil evidence that are not quite homo sapiens found in places like Asia which supports the multiregional theory where older homo sapiens evolved simultaneously in different locations.

people died of starvation and less chance of injury. Job-sharing, fewer people needed to work at providing food for many allowing others to specialize at other skills. More permanent settlements at sites near sources of water as they were able to produce more food then they needed so traded with other people for other things they needed.

Genetic Analysis: This can determine

Intelligence: Neanderthal: They buried the dead, looked after their

Disadvantages: Restricted diet, to what they could grow. Dependant on weather to grow crops. Time consuming, fighting over animals and territory fights over ownership.

Mitochondrial DNA Analysis: Only

elderly, and had strong social bonds. With the dead were tools and flowers indicating ritualistic behaving suggesting they believed in after life.

Hominin Communication: It is suggested that H. Habilis were the first to speech. They did not have a voice box so it would likely have been grunting sounds. The larger brain and Broca’s area suggest they were

Hominin: The closer the hominin species to humans the capable of speech. Homo erectus had an even larger brain, suggesting they had advanced speech though still not complete sounds. It wasn’t till Neanderthals and Homosapiens proper sounds were made. Even though speech wasn’t present before Homohabilis the other hominin species still had social structures.

The tool use: example of cultural evolution as it passes knowledge Advantages of Fire: Increased home-based activities as more light availability. Protection from dangerous animals. Can be used to harden wooden spear points (tool manufacture). Stampede animals into traps (hunting). Cooks food kills microbes making it safer to eat and makes it last for longer whilst being more palatable and

cannot be absorbed. Circulation of blood back to the heart goes

Human origin and dispersal

multiple purposes such as cutting up carcasses, cutting wood and scraping or cutting hides.

that was used to create and advance tools from older generation through to younger generation. The use of tools allows hominins to hunt prey, work together enhancing communication and language

Slower movement speeds, less stable on two feet than four, Prone

Better Thermoregulation: The decreased surface area for the sun to hit allows for us to keep cool in savannah climates.

Farms: Helped advance cultural, evolution with new skills and tools developing as a result. It also meant that less time was spent gathering food and allowed for more time on things like arts and crafts.

more intelligent they were. It is said intelligence correlates with brain size.

Disadvantages of Bipedalism:

to back aches due to S-shape spine, requires smaller pelvis, which is

Better Energy Efficiency: Walking long distances as bidepalists only use ¼ the energy a chimpanzee uses when walking on all fours.

physiological, and behavioural adaptation passed on from parent to offspring via genes. The result of natural selection over many generations.

generation to another, not through DNA or Biological means but through social interaction.

Skull: Foramen magnum at the back of the underside of the skull to position the head appropriately when on all fours. Nuchal crest is large to avoid head from drooping. Spine: C-shaped spine, this counters the force of all organs being pulled by gravity when walking on all fours.

when, where and how humans originated. passed on by the mother of the offspring therefore crossing over and other factors in meiosis do not alter the DNA. This can be used by scientists to determine how long two species or even two individuals shared a common ancestor by comparing their mitochondrial DNA.

Y-Chromosome analysis: Only passed down from father to son and is not altered during meiosis. It also can be used similarly by scientists as mitochondrial DNA analysis.

Hominin specie dispersal: It is thought that dispersal was linked to climate change. Around 1-2mya the climate changed, and landscape dramatically changed. Sea levels dropped, new lands was exposed, forests shrunk, and grasslands or savannahs popped up. Populations which stayed put were either to lazy to leave or more likely better adapted to the new climate and or food sources or were geographically isolated.

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