10.5 evidence of the migration of modern human populations

different models of human migration

multiregional hypothesis - Homo sapiens evolved in different parts of the world, in parallel, from populations of Homo erectus

out of Africa hypothesis - Homo sapiens evolved from Homo heidelbergensis 300,000 years ago in Africa, and 70,000 years ago they migrated out of Africa and spread across the rest of the world, replacing populations of other hominin species

evidence that has changed understanding of human migration

fossils of H. sapiens in Israeli caves dates back to ~180,000 years ago, which is much earlier than the 70,000 from the out of Africa theory

the out of Africa II hypothesis was created to rectify this

fossil evidence for human migration

fossils found in Israeli caves

• upper jawbone ~180,000 y/o

• five individuals ~120,000 y/o

• 7 adults, 3 children ~90,000 y/o

mtDNA

• shows maternal lineage

• has a higher mutation rate (no repair mechanisms)

• small amount of genetic material

• takes longer to degrade compared to nuclear DNA

haplotype

a region of DNA in the D-loop of mtDNA that varies between individuals

haplogroup

a group of people with similar haplotypes who share a common ancestor

mtDNA as evidence of human migration

mtDNA allows scientists to trace maternal lineages and genetic diversity through geographically specific variations in DNA sequences and haplogroups

migration of Aboriginal and Torres Strait Islander populations

• their ancestors moved out of north-east Africa through the Middle East and Asia, and then travelled to the landmass of Sahul

• oldest living cultures in the world, with a rich connection to Country and Place

• have been living in Australia for 50-60,000 years

• large variation in haplogroups reflects large time frame from when A&TSI diverged from other groups