Dispersal theories

Question 1

How many years ago did H.erectus migrate out of Africa?

Answer 1

1.5mya

Question 2

Multi-regional theory (regional continuity)

Answer 2

• H erectus migrates to Asia and Europe 1.5mya
• Continual movement of genes between populations (inTERbreeding between countries)
• In three areas H erectus evolved into H sapiens concurrently (at the same time)

Question 3

Out of Africa/Replacement Theory

Answer 3

• H sapiens developed in Africa 200k ya
• Then took over other hominins and outcompeted them in different areas of the world
• NO MOVEMENT of genes between populations
  NOTE - some H. erectus left 1.5 mya as suggested but became extinct outside of Africa due to the harsh conditions

Question 4

Evidence multiregional

Answer 4

• Fossils that are halfway between H. erectus and H. sapiens found in Africa
• DNA evidence has shown interbreeding
• Other ways to justify a population dying out

Question 5

Evidence out of Africa

Answer 5

• People who live in Africa have the greatest genetic variation suggesting they’ve been around for the longest time to develop genetic diversity (less G.D. in Asia and Europe
• All modern humans have similar genes and nuclear sequences (would’ve had more variation if parallel like multiregional evolution)
• H. sapiens found in Africa at SAME TIME as H.erectus and neanderthals so didn’t evolve together
• Common male ancestor due to Y-DNA 120-200k ya
• Common female ancestor due to mtDNA 140-200k ya

Question 6

Comparing DNA

Answer 6

Sequencing - if species are similar will have areas of similar sequence
Hybridisation - if DNA is similar, mpt for DNA similar

Question 7

mtDNA

Answer 7

• Doesn’t undergo recombination
• Inherited down the maternal line
• Constant mutation rate so can trace back to the change

Question 8

Y-chromosome DNA

Answer 8

• Doesn’t undergo recombination
• Inherited down the paternal line