11D Flashcards
Evidence for examining homosapiesn past
- fossil records to determine relatdness with other species like Naedethnrals
2.Molecular homology( DNA sequences or amino acid sequences)
3.New fossils are still bein discoverd
4.Many fossils have differnet interpretations of human fossil records
Various theories on the evolution of humans:
Multiregional hypothesis
Out of Africa Hypothesis
Out of Africa Hypothesis
Suggests that Homo sapiens evolved in Africa around 200,000 to 300,000 years ago then emigrated 100,000 years later to Europe, Asia and austriala, replacing existing hominin species such as Homo erectus.
Most widely accepted hypothesis
Evidence of out of aFRICA hypothesis
Evidence:
-mtDNA analysis of modern humans trace back mitochondria lineages from a common ancestor in Africa
-Modern humans show little genetic diversity compared to other species suggesting we originated from a small centralised population
-Oldest Homo sapiens fossil found in East Africa dated 160,000 years compared to fossil in middle East 100,000 years old.
-Evidence of tools, cave paintings found in regions of Western Europe around 40,000 years old.
Multiregional hypothesis
Suggests evolution of modern humans from Homo erectus to Homo Sapiens was an ongoing process across all regions of the world with gene flow between different continental populations.
Homo erectus moved out of Africa to other parts of the world
Homo erectus evolved into Homo Sapiens in different regions
Limited evidence.
Not accepted.
When was the arrival of aboriignal australians
Arrival of Aboriginal Australians between 50,000 and 65,000 years ago.
Q: What does genomic research suggest about modern Aboriginal Australians’ ancestry?
: It suggests that they can be traced back to the ‘out of Africa’ model when the first humans spread throughout the world.
What is Sahul?
Sahul was a supercontinent that included present-day Australia, New Guinea, and Tasmania, which became geographically isolated due to rising sea levels.
What evidence exists of the impact of Aboriginal Australians’ migration
Evidence suggests the extinction of large Australian terrestrial animals 42,000 years ago due to the rapid migration of Aboriginal Australians.
Migration of aboringal asustrialains
The first migrants reached Sahul, a supercontinent that included Australia, New Guinea, and Tasmania. Rising sea levels later separated this landmass, leading to geographic isolation. This isolation impacted the region’s flora and fauna, contributing to the extinction of large Australian animals around 42,000 years ago
‘Country’:
refers to relationship between individuals and ancestral lands and seas
whatdoesthelanddo
The lad provides for the people, and the people manage and sustain the land through culture, ceremonies and care
Important to acknowledge the land and original migrants
Proof that humans breed with Neanderthals
Evidence suggests crossbreeding between the two species
Neanderthals were our close evolutionary cousin
Both existed in Europe and Asia between 40,000 and 100,000 years ago
mtDNA from Neanderthal fossils suggest we were a separate species that shared a recent common ancestor around 400,000 years ago
Comparing Neanderthals and Humans
Neanderthals had:
Wider nose
Shorter limbs
Stockier build
Enlarged brow ridge
Larger cranial capacity
Better resistant to cold climates
Evidence to suggesting interbreeding between humans and Neanderthals
Evidence: Nuclear DNA studies show 1-4% of human genome is identical to Neanderthals. Only found in non-African populations and not in sub-Saharan African genomes. This suggests Neanderthals may have interbreed with humans as they left Africa and did not interbreed with African humans
Evidence: 100,000-year-old Neanderthal fossil in Siberia contained human DNA. This suggests that a population of Neanderthals in Siberia interbred with humans 100,000 years ago.
