BIO 3062 CULTURAL EVOLUTION OF HUMANS Flashcards
Out of Africa / replacement model
Postulates that only the African descendants of Homo erectus gave rise to modern humans. About 100 000 years ago, Homo sapiens, descended from Homo erectus, migrated out of Africa and completely replaced the regional populations of earlier Homo erectus people, giving rise to all the diverse human populations in different parts of the world today.
Multiregional model
Postulates that modern humans evolved independently by parallel evolution in many parts of the world, from the descendants of the Homo erectus people who left Africa about 1.5 million years ago.
Where did the first wave of homo erectus people spread when they made their way out of Africa
They made their way out of Africa and gradually spread into Europe and across to Asia even as far as indonesia.
It was shown by fossils of Java man and Peking man.
How is the Multiregional model supported
This view is supported by 100 000 year old fossil evidence from China that seems to suggest a mixture of Homo Erectus and Homo Sapiens traits.
It is now in the minority
How is the Out of Africa model supported
By genetic data
Give evidence to support that the Out of Africa is likely to be more correct than the Multiregional one
-fossil evidence suggests that in Western Europe the Neanderthals were replaced by modern humans.
-modern humans were the early Europeans called Cro-magnons abt 400 000 years ago.
-comparisons of mitochondrial dna of the Neanderthals with modern humans suggests no interbreeding. However, genomic data suggests limited interbreeding.
-implies that Neanderthals were almost entirely replaced by modern humans rather than developing into modern humans.
-divergence from a common african ancestor about 100 000 years ago by using Y chromosome studies from different geographic regions.
-no mitochondrial lineages or Y chromosome lineages older than 100 000 years have been found.
Explain the founder effect
The individuals that left Africa were representative of only some of this genetic diversity, which is why there is less genetic diversity in other populations.
Low amount of genetic diversity in modern humans today suggests that our origins reflect this small founding population of Homo sapiens from whom we are all descended.
Give evidence that supports Multiregional model.
-not completely supported by scientific evidence.
-fossils from asia show a clear transition from older hominin forms to modern Homo sapiens, and that the oldest Homo sapiens fossils putside Africa were found in Australia, dated about 60 000 years old .
How did humans reach New Zealand
-mitochondrial DNA suggests that original population from Taiwan gradually spread south and eastwards theough the islands of South-East Asia and from there into the pacific.
Gradually prople spread across islands into central Pacific around Samoa. From there they spread North to Hawaii eastwards to Rapa Nui and finally southwards to New Zealand.
Nz was last landmass to be populated 1000 years ago
Give evidence that New Zealand was the last land mass to be populated about 1000 years ago.
DNA from polynesians gets more similar the further east they are, suggesting they originated in the West, where populations had greater genetic diversity, and moved eastwards.
Māori are the least genetically diverse of all, which backs up scientific evidence that New Zealand was the last region of the Pacific of the pacific to be settled by a small founding population.
Which species was the first that learned how to control and use fire ?
Homo erectus
Timeline of Mesolithic
20 000 years ago - 10 000 years ago
Timeline of Upper Paleolithic
40 000 years ago - 20 000 years ago
Timeline for Middle Paleolithic
300 000 years ago - 40 000 years ago
Timeline for Lower Paleolithic
2.5 million years ago - 300 000 years ago
When was the earliest evidence for the use of fire
-from bones found in a cave , The Cave of Hearths, in the Zwartkrans valley, in the north of South Africa.
-bones appear to have been heated at a high temperature (higher than in normal bushfires)
-later evidence links the control of fire to Homo erectus
What is evidence of the use of fire
-charred bones
-charcoal layers
-stones that have been thermally altered
-hearth (may be a ring of stones around the charcoal)
-tools that appear to have been fire hardened
Which benefits did the controlled use of fire give early Homo species ?
-been able to keep warm at night & allow them to move out of Africa into colder, more temperate climates such as Europe
-protection from animals (predators), reduce the death rate from predation
-used to hunt animals, driving them over cliffs or areas to be easily captured
-provide light at night, encouraging socialization & allowing activities to be carried out later the day (toolmaking).
-food could be cooked, to make it more palatable, enhance flavour and make it easier to digest. Range of foods increased, as cooking destroys toxins and kills parasites and bacteria in meat.
-increased healthier food supply lead to increased life span. Lead to increase in other cultural developments and learning.
-ability to cook food would’ve allowed humans to spend less time looking for food as hunter-gatherers. More time for other pursuits such as toolmaking.
-diet changes, as food became more palatable, explains why later Homo species had smaller jaws and teeth.
-enhanced diet lead to increase in brain size, because brain is an organ that demands high energy input.
Oldowan tools
-olduvai gorge site found by Louis Leakey
-made by Homo Habilis, the ‘handy man’
-stone tools found at olduvai is known as oldowan
-earliest stone tools about 2.5 million years old
-pebble tools because the stones look like broken pebbles and are very simple
-formed by striking off a few flakes from a rock, using another stone, leaving rounded and pointed edge.
-used to get marrow out of bones, butcher meat, crushing through plants, digging up roots to eat, opening nuts and seeds.
Acheulean tools
-more complex tools discovered at a french site , Saint-Acheul.
-tools were dated at about 1.6 million years old
-named after village where they were found
-made by Homo ergaster or Homo erectus in Africa and later by Homo heidelbergensis in Europe.
-classic teardrop or almond shape
-pointed at one end blunt at the other end
-both sides of stone were worked and core stone was used rather than the flakes
-first hand axes, chisel-like cleavers for scraping and cutting
Broca’s area and Wernicke’s are
Two areas of the brain that are essential for speech, as they contain the nerve linkages that coordinate the throat and mouth muscles.
