Irish Genes and Ancestry - Eneclann

23 Pages·2012·2.44 MB·English

Copyright Gianpiero Cavalleri
Irish Genes and Ancestry
Dr. Gianpiero Cavalleri
Eneclann Summer Lunchtime Series 2012
Detailed genetic ancestry information
through state of the art gene analysis
Copyright Gianpiero Cavalleri
Overview..
•
Introduction to DNA, Y chromosome, mtDNA
•
How DNA has informed us about global
population history
•
Patterns of Y chromosome types we see in
Ireland
•
How genetics can inform on genealogy
•
Sources for more information
Copyright Gianpiero Cavalleri
•3 billion letter archive written in ACGT
•Only small portion of our DNA (the genes) encodes instructions to build
a human
•Changes (mutations) occur in our DNA with each generation
•These chages are inherited down through generations
•~99.9% of our DNA is identical
Copyright Gianpiero Cavalleri
Copyright Gianpiero Cavalleri
Single nucleotide polymorphism (SNP)
CGTACTATGACCCGAGCTAGCCCTA Pat
CGTACGATGACCCAAGCTAGCCCTA Jack
M269 M182
Microsatellite/short tandem repeat (STR)
CCGTGCATGCATGCATGCATGCACC
Pat (5 copies)
CCGTGCATGCATGCATGCATGCATGCACC Jack (6 copies)
DYS19
“T” at M269 + “G” at M182 + “5” copies at DYS19 = haplotype
i.e. combination = haplotype
Copyright Gianpiero Cavalleri
 Groups and types found at different frequencies in
different populations
 Isolation (i.e. within population marriage) and fact that
some people have more (grand)children than others
Isolation!
0.45
0.4
Distance between spouse
0.35
birthplaces for all marriages
0.3
1855-1955
0.25
%
0.2
0.15
0.1
0.05
0
0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 ?
distance (miles)
 Basis of all genetic history work
Copyright Gianpiero Cavalleri
mtDA
mtDNA tree Y chromosome tree
Copyright Gianpiero Cavalleri
The evolution of modern humans..
Homo erectus
Approx 1.8 – 1.1 mya
Radiated from Africa to Europe & Asia
Copyright Gianpiero Cavalleri
Homo sapiens spread and diversified, moving
out of Africa approx 100 kya
Early migration towards South East Asia – approx 100 – 60 kya
Later migration towards Eurasia 70 – 40 kya
As a consequence –
we expect to observe in non-Africans, a subset of genetic variation
present in modern African populations
Copyright Gianpiero Cavalleri
R1b across Europe..
~150k years ago ~80k years ago
~60k years ago ~40k years ago
~25k years ago LGM ~18k years ago