OUT OF AFRICA II (Origins of modern humans) Flashcards
What happened When Homo ergaster left Africa?
- Some went to europe
- Some went to Asia/java etc
H. ergaster/erectus spreading across eurasia
H. ergaster/erectus spreads across Eurasia and begins to diverge in the different environments/habitats (cf. intraspecific versus interspecific variation)
Key questions in the migration of H. ergaster/erectus
- How many waves of migration were there?
- Was there two-way gene flow between Africa and Eurasia? Yes possibly some evidence for this.
When did Homo heildelbergensis first appear?
600,000 years ago
Found in Africa and Eurasia
When did H. neanderthalensis first appear?
- 400,000 years ago
- Europe/ Western Asia
When did H. sapiens first appear?
- 200,00 years ago
- In Africa
What did H. heidelbergensis give rise to?
- neanderthalensis in Europe/ Western Asia
- sapiens in Africa
Where did neaderthals live?
- Europe /western Asia
- Lived in caves
- Adapted to cold climates
Body structure of neanderthals?
- Rubustly built
- Adapted for routine heavy work as hunter gatherers
- Protruding long face with long nasal passages
- Large brain
Could neaderthals speak?
- Evidence for limited speech
- Hyoid bone - shape more like modern human
- Larynx structure
- Large hypoglossal canal - massive nerve transport
Evidence that neaderthals were self aware?
- Practiced ritual burials
- Produced stone tools ans worked wood
- Adorned bodies with jewellery
What was the range of neanderthals?
Across Europe and western Asia
What does the multiregional model suggest?
- African & Eurasian H.ergaster/erectus evolved into various species of Homo in different parts of the world
- Differences we see today are as result of this and millions of years old
- NOT THE ACCEPTED THEORY
What is the Out of Africa II Model ?
- H. ergaster/erectus evolves into H. heidelbergensis in Africa & Europe (600,000 years ago)
- H.heidelbergensis gives rise to H. neanderthalensis in europe (400,000 yr)
- H. heidelbergensis gives rise to H.sapiens in Africa (200,000 yr)
- By around 100,000 yrs ago H. sapiens migrates out of Africa
- H. sapiens outcompetes archaic hominins (erectus, heidelbergensis and neaderthalensis)
Which is the most accepted theory for sapien evolution?
Out of Africa model II
What happened to neaderthalensis?
- Neanderthals died off in and east-west progression between 40,000 to 27,000 years ago. The occurrence of AMHs follows the same trajectory.
- Competitive replacement or genocide?
- No other Homo could survive with sapiens
Denisovan man ?
- New species
- Based on 41,000 year old teeth and finger bone from a cave in Siberia.
- Recovered DNA shows it is different from both H. neanderthalensis and H. sapiens.
- Newly discovered jaw bone from Tibet.
What did sapiens mix with?
- Denisovan man shares some DNA with extant H. sapiens populations that migrated east
- Neanderthals share DNA with extant H. sapiens populations that migrated west
- Interbreeding between neanderthals, sapiens and denisovan man
- Sapiens interbred with neanderthal in the west
- Sapiens interbred with denisovan in east
“Hobbit” people of indonesia (Homo floresiensis)
- Dwarfed hominin - evolving from H. erectus by insular dwarfing.
- H. erectus lived in Indonesia from 1 Ma but H. sapiens only arrived 12,000 years ago.
- Discovered in 2004 from a cave on the island of Flores, Indonesia.
- Dwarfed hominin from 95,000-17,000 years ago. 1 metre tall, weighing 30 kilograms with a brain only 417 cm3.
- Used primitive tools and fire and hunted dwarfed elephants and giant lizards (Komodo dragons)—but no art.
What is the Mitochondrial Eve hypothesis ?
- mDNA variation is lower than expected in modern humans
- Greatest in Africans
- Molecular clock work
How does molecular biology give evidence for the out of Africa II model?
- Mitochrondrial Eve hypothesis
- Evidence from nuclear genes and the Y chromosome
- Archeological and palaeological remains - DNA
- Neaderthal ans Denisovan DNA shows inbreeding
- All shows that Africa was a sister group to the rest of the world
