4.2. Tracing populations with Haplogroups

Transcription

4.2. Tracing populations with Haplogroups
4.2. Tracing populations with Haplogroups
The definition of a haplogroup is the group of all the paternal
descendants of the single person who first showed that SNP mutation.
Example for mutation creating Y Haplogroup I1,
which characterizes Scandinavian populations.
Y-chromosome DNA
X-Y inheritance, females carry XX
chromosome pair, males carry XY
chromosome pair.
Females get X from mother and the X
from father.
Males get x from mother and Y from
father.
Y-chromosome is exclusively passed
on along male line from father to son!
Y Haplogroups
A
BT
B
CT
CF
DE
C
F
D E
G H
IJK
IJ
K
I
J
L M NO P S T
N O Q R
Neolithic Farmers
Y Haplogroups E1b1b (yellow)
(formerly 3b) and G (green)
are common among Neolithic
farmers from the Middle East
who brought agriculture into
Europe about 9000 years ago.
The date of the most recent
ancestor of E3b haplogroups
is estimated to 24-27 thousand
years ago. The most likely
origin is eastern Africa.
Haplogroup G originates in
Iran, Caucasus region, 60% in
North Ossetians, 30% in
Georgians
Bantu Migration
Bantu migration was reflected
in the spread of iron smelting
techniques from West-Africa
to East- and South-Africa
Confirmed by genetic tracing of
haplogroup E1a1b (formerly E3a).
The Haplogroup R1
From Western Europe to Central Asia
Reflection of the Tarim Mummies?
R1b red
R1a purple
Origin of R about 30,000 years ago !
Distributed by ice age and resettlement
The Mitochondrial Eve
When sperm and ovum fuse nuclear
DNA is distributed in equal amounts.
Mitochondrial DNA is only passed on
by ovum, from mother to daughter.
The development of new Eve’s
Chronological development of
mtDNA haplogroups
U => 50,000 to 60,000 years ago (arose in Western Asia)
H => 30,000 to 50,000 years ago (in the Near East - associated
with Cro-Magnon in Europe)
J => 45,000 years ago (in the Near East)
X => over 30,000 years ago (in Caucasus) (Neanderthal???)
I => 30,000 years ago (origin unknown - probably in Europe)
W => 25,000 years ago (in north-east Europe or north-west Asia)
K => 15,000 years ago (in the Near East) (Oetzi)
T => 10,000 years ago (in Mesopotamia)
V => 10,000 years ago (arose in Iberia and moved to
Scandinavia)
Mitochondrial Haplogroups
mitochondrial DNA haplogroup is defined by differences in human
mitochondrial DNA. This allows to trace the matrilineal inheritance of modern
humans back to human origins in Africa and the spread across the globe.
Out of Africa, again
Brother Neanderthal
Or that?
Where they like this?
Gen sequence
from bone material
Molecular analysis of Neanderthal DNA from the northern Caucasus;
I. V. Ovchinnikov, A. Götherström, G. P. Romanova, V. M. Kharitonov,
K.Lidén and W. Goodwin; Nature 404, 490(2000)
Separation and Difference
Distinct differences in human
genetic structure compared to
Neanderthal and Chimpanzee.
Human red
Neanderthal blue
Analysis of one million base pairs of Neanderthal DNA
R. E. Green, J. Krause, S. E. Ptak, A. W. Briggs, M. T. Ronan,
J. F. Simons, L. Du, M. Egholm, J. M. Rothberg, M.Paunovic &
S. Pääbo; Nature 444, 330 (206)
Is there indication for genetic linkage?
Based on lack of identification
of any Neanderthal genes in
human DNA and on results of
theoretical population models
the maximum initial input of
Neanderthal genes into the
Paleolithic European gene
pool has been estimated to lie
between 0.02% and 0.09%.
Population genetics simulation showing the percentage of Neanderthal
genes (red) of the total number of genes in European population if free
interbreeding would have occurred in areas of contact.
Modern Humans Did Not Admix with Neanderthals during Their Range Expansion into Europe
M. Currat and L. Excoffier; PLoS Biol 2(12): e421 doi:10.1371/journal.pbio.0020421
The last resort