Transcript Africa to Aotearoa part 1

From Africa to Aotearoa
The story of
human
migrations
Part 1: Out of Africa
The spread of modern humans from
Africa through Europe and Asia
Part 2: To Aotearoa
Human migrations across the Pacific
to New Zealand
The modern human lineage originated
in Africa less than 200,000 years ago
The earliest
modern human
fossils are from
Ethiopia
Human skull from
Herto, Ethiopia, dated
to 160,000 years ago
Reprinted by permission from Macmillan Publishers
Ltd: White et al. (2003) Nature 423, 742-747 © 2003
Modern humans: Out of Africa
Europe
Africa
Mitochondrial Eve
Homo erectus
Africa
Asia
Early human fossil from Israel, dated to 90,000-100,000 years ago
DNA and
fossils can give
different types
of information
By comparing DNA changes among
populations we can trace their history
Population 1:
Population 2:
Population 3:
Population 4:
1
ATGTAACGTTATA
ACGTAACGTTATA
ACGAAACGTTATA
ACGAAACCTTATA
2
3
4
Mitochondrial DNA traces the female line
Mitochondria:
DNA comes
from mother
Nucleus: DNA
comes from
both parents
Offspring cell
Mitochondrial DNA suggests migrations out
of Africa began around 65,000 years ago
40,000
65,000
150,000
50,000
The Y chromosome traces the male line
Y chromosome
lineages began
to diverge
about 60,000
years ago
Migration patterns of early humans
Y chromosome
Mitochondrial
DNA
https://genographic.nationalgeographic.com/
By sequencing whole genomes we can see
the genetic signatures of our ancestors
Genome sequences suggest two
migrations into Asia
An Aboriginal Australian Genome Reveals Separate Human
Dispersals into Asia
Morten Rasmussen, Eske Willerslev and colleagues, University of
Copenhagen, Denmark
Science 2011; Vol. 334 pages 94-98
40,000
60-75,000
150,000
Genome sequences suggest two
migrations into Asia
African
European
2
1
Chinese
Melanesian &
Aboriginal
25,000-40,000 yrs ago
60,000-75,000 yrs ago
Whom did Homo sapiens meet as they spread
through Europe and Asia?
Neanderthals
lived in Europe
150,000 to
30,000 years ago
Did Neanderthals and Homo sapiens interbreed?
Comparison of Neanderthal (left) and modern human skulls
Fossilised bones provide a source of
Neanderthal DNA
Neanderthal sampling sites
A draft sequence of the Neandertal genome
Svante Pääbo, Richard Green and colleagues, Max Planck Institute for
Evolutionary Anthropology, Germany
Science 2010; Vol. 328 pages 710-722
African
European
Chinese
Melanesian
Interbreeding (2%)
Neanderthal
Denisova Cave, Siberia
© Max Planck Institute for Evolutionary Anthropology
Genetic history of an archaic hominin group from Denisova Cave in Siberia
David Reich, Svante Pääbo and colleagues, Max Planck Institute for Evolutionary
Anthropology and Harvard University, USA
Nature Vol 468, 23/30 December 2010
African (San)
European
Chinese
Interbreeding
Melanesian
Neanderthal
Interbreeding
Denisovan
Neanderthal
Denisovan
150,000
Out of Africa, with some hybridisation
• Modern humans are mostly of recent
African origin
• The contribution from Neanderthal and
Denisovan hybridization is small
Over 10,000 years, one mating
event every 25-50 years.
What does “race” mean?
Our recent African origin means our “racial”
characteristics evolved only recently
60-75,000
19th century:
Human races
different
species?
Racial features are the result of
superficial genetic changes
“We are all Africans under the skin”
Blue eyes result from a single genetic
change less than 10,000 years ago
Percentage of
Europeans with
light-coloured eyes
When you look at the underlying genetic
variation, we are much more similar than
we appear on the surface
0.1%
variation
Most human genetic variation occurs
within populations
Africa
Asia
Europe
Most human genetic variation occurs
within populations
85-90% variation
within populations
10-15% variation
between populations
Differences between ethnic groups are minor
compared to differences among people overall
Ancestry, not race
Y chromosome
Mitochondrial
DNA
Thanks to Azra Moeed, Terry Burrell,
Barbara Mavor, and Glenda Lewis for
assistance with preparing this presentation
© Produced by Hilary Miller in association
with the Allan Wilson Centre for Molecular
Ecology and Evolution
[email protected]
www.allanwilsoncentre.ac.nz
Photo credits
Slide 3: Science Photo Library
Slide 4: MacMillan Publishers
Slides 6, 7: Science Photo Library
Slide 9: Univ. of California Museum of Paleontology (http://evolution.berkeley.edu)
Slide 10: Blank map from Wikimedia Commons (Author Crates)
Slide 11: Wikimedia Commons (Courtesy: National Human Genome Research Institute)
Slide 12: Constructed with information from National Genographic maps and the Genographic project
Slide 14: Science Photo Library
Slide 15: iStockphoto
Slides 18-20: Science Photo Library
Slide 21: Science Magazine, American Association for the Advancement of Science
Slides 22, 24: Science Photo library
Slide 25: Max Planck Institute for Evolutionary Anthropology
Slide 28: Science Photo Library
Slide 29: TRANZ International Image Library Ltd
Slide 31: Science Photo Library
Slide 32, 33, 35: TRANZ International Image Library Ltd
Slide 33: Wikimedia Commons (Author: NordNordWest)
Slide 34: Emmanuelle Bournay, UNEP/GRID-Arendal
Slide 38: Constructed with information from National Genographic maps and the Genographic project