Human Evolution Flashcards
The Primate Family Tree
- Prosimians (loris) (Lesser primates) 60 - 65 MYA
Simiiformes (Higher Primates)
- New World Monkeys (Marmoset) 35MYA
- Old World Monkeys (Rhesus Macaque) 25 MYA
- Hominoids
- Lesser Apes (Gibbons) 18 MYA
- Greater Apes (Orangutan) 12 MYA
- Greater Apes (Gorilla) 7-8 MYA
- Greater Apes (Chimpanzees) 6-7 MYA
- Human Present
Physical Evolutionary Trends in Hominins
- Increase in cranial capacity
- Increase in number of convolutions and size of frontal lobe
- Decrease in brow ridges/increase in forehead
- Decrease in prognathism
- Teeth becoming smaller (especially molars) and more generalised
- Presence of a chin and prominent nose
Cultural Evolution of Hominins
- As the environment changes over millions of years, the characteristic of organisms change to suit the environment
- Hominins are no different. Hominins have evolved through natural selection to become more suited to their environment
HOWEVER
- Hominins have also developed a complex culture:
- tool making, hunting techniques, food preparation, using language and art
- Cultural development was important in overcoming some environmental challenges faced by early humans
Australopithecine Culture
- A.afarensis, A.africanus (4 - 2.5 MYA)
Home bases
- areas occupied by small groups/social behaviour
Food
- Early australopithecines foragers:
- fed on hard plant material (seeds, grains, pods), tough chewy plants. Large molars to help chew tough food.
- Later species were hunters or possible scavengers of meat
Tool use and manufacture
- unsophisticated tools with simple modifications
- sticks and range of pebble tools
- scrapers and flakes
- choppers for chopping food
- referred to as Oldowan tools
- simple tools enabled them to exploit resources
- enabled them to explore new habitats
- lead to them leaving Africa for new continents
Early Homo
- Homo habilis (2.5 - 1.5 MYA)
- Distribution: Eastern Africa
- Lived in groups in temporary living sites
- Bipedal locomotion but still arboreal lifestyle at times
- Larger brain: significantly larger than australopithecines. Shift to meat eating would have been necessary for this. Consuming high energy foods (Omega-3 fatty acids), a change in behaviour would have occured.
- Scavengers/hunter-gatherers: largely carnivorous feeding on scavenged meat but also plants. Homo would have been more aware of their surroundings. Food sharing would have had to occur changing the social structure of early hominins
- Evidence: bones showing cut marks made by tools and also teeth marks. Suggests both scavengers and hunters as some teeth marks occured before tool marks
- Speech evidence: communication would have been important in a social group sharing food and working as a team (hunter-gatherer lifestyle)
- Evidence: bulge in the speech-producing area of the brain (Broca’s area) - beginnings of language
- Tool use and manufacture: simple pebble tools fashioned from lava cobbles
- Oldowan tools: typically have flakes knocked out to produce a cutting edge
Later Homo - erectus
- Homo erectus (long lived species 2-0.8 MYA)
- Africa then Europe and Asia
- Brain: increase in brain size and complexity, suggest that there were strong pressures for increased intelligence
- Big game hunters and hunting gathering societies - largely carnivorous diet (meat and fish). Increasingly complex society - skillfull hunters who were capable of logical thought and had the ability to communicate and work with others in an organised manner. Evidence of cannibalism.
- Evidence: massive slaughter sights found with bones of prey, tools and stones. Indicates hunt must have been well organised. Butchery marks also present on fossible bones indicating systematic use of tools
- Speech evidence: Broca’s area showing larger swellings. A language could have arisen by this time and helped H.erectus to communicate when hunting.
- Acheulian tools - sophisticated stone tools manufactured with precision gives competitve advantage over other predators
- Typically biface shaped - bulges outwards on both sides and has a tear drop shape. Each tools has a great many of blows to remove flakes
- Used as hand axes. Evidence of scalping suggests from of ritualism.
- Evidence: tool manufacturing sites found with stone and bone tools
- Evidence from sites of FIRE and SHELTERS (e.g. Terra Amata site)
- manipulating the environment to suit their own needs
- fire used for warmth, light, deter predators, cooking more foods making them easier to digest, to stampeded animals for hunting, allowed migration to cooler nights (thought to be the first to venture out of Africa into Europe/Asia)
Later Homo - Neanderthalensis
- 150,000 - 30,000 YA
- Distribution: Europe, Middle East and South west Asia (Colder climates)
- Co-existed with H.Sapiens for thousands of years
- Hunters: reliant on meat and also plant foods during the seasonal changes. Smaller generalised teeth. Hunted large migratory hed animals such as mammoths.
- Mousterian tools - more refined tool culture. FIint being used to produce tools along with wood. Some points crafted to spears on wood e.g. Fine points, sharp knives
- Scrapers: tools used for preparing animal hides have been found. Evidence of first use of CLOTHING. Keep warm in cooler climates.
- Speech evidence - they had a similar voice box to modern humans, possibly spoke rudimental language.
- Burials/Rituals - believed in life after death/religious belief?
- Evidence: grave sites of young fossil bones found alongside artefacts such as being surrounded by goat horns or beds of flowers
- Shelters and fire use continued - possible cave shelters to keep warm
- Creativity - wood carvings, clothing with natural pigment, decorating bodies
- What killed them off?? Possibly competition with modern humans*
The Denisovan Hominin
The Denisova Cafe Findings - Siberia
- A finger bone was found in Denisova cave, 2010
- It was carbon dates as being 40,000 years old
- When genetically tested, it was that its mtDNA was neither modern human or Neanderthal
- Lead to the belief of a now extinct hominin species called the Denisovans which existed at the same time as modern humans and Neanderthals
- Based on the similarity of mitochondrial bases to both humans and the Neanderthals, it is believed that its common ancestor to us lived 1 million years ago
The Denisovan Molar Tooth
- A second bone and tooth found in a cave
- Tooth not similar to modern human or neanderthal
- Suggest Denisovans were a distinct hominin group
Nuclear DNA comparisons:
- Findings show Denisovan’s interbred with ancestors of present day Melanesian’s
- Evidence: Melanesian DNA includes 4-5% Denisovan DNA. Australian aboriginal people have also been shown to have some Denisovan ancestry.
- Unlikely to have interbred in Siberia so Denisovans must have lived over a large area of Eastern Asia
Early Modern Humans = Cro-Magnon people
- Homo sapiens = 100,000 - present
- Distribution: originally Africa, ghen southwest Asia, Europe (40,000YA) and eventually worldwide
- Hunter-Gatherers: exploited numerous food resources and hunter whole herds - bison, mammoth. Later a farmer with animals and cultivated crops capable of supporting large populations
- Advanced tool making - sudden increase in sophistication of tool making about 35,000 YA.
- Aurignacian tools - blade tools = flakes of stones with parallel sides
- The later cro-magnon people demonstrated two other cultures:
- The solutrean culture: tools characterised by willow-leaf and laurel-leaf points. More made as an indicator of the tool makers craft or for ornamentation than for practical use.
- Magdalenian culture: dominance of bone and antler tools and artwork. They devised tools to make other tools (use of Burin to make tools out of bone such as the spear thrower)
- Clothing and Shelter: better methods of constructing clothing from animal hides and shelters, which allowed them to survive the colder climate of Europe
- Creativity/Arts - they produced portable art such as carved figures and mural art (cave paintings)
Beginnings of Agriculture
- Neolithic Revolution: the change from a nomadic lifestyle to living in settlements
- Characterised by the domestication of plants and animals
- Can support large numbers of people living in a smaller area of land
- Middle east (fertile crescent) page 331
- Used flint tools in the shape of a sickle to harvest wild grasses (wheat) for food
- This domestication of food allowed for the specialisation of skills and the development of religious and cultural beliefs and practices
- There was more time left for these pursuits and less time was spent on obtaining of food
- Surplus = allowed to settlements and the increase in population
- As the populations grew, the social organisation of humans would ave become increasingly more complex and the need for more space would have resulted in the warring of neighbouring villages and the trading of goods and food between villages
- Eventually the development of leaders/rulers and what is now referred to as civilisation would have occured
