Many DNA testing laboratories are advertising ethnicity or ancestral population percentages for participants – but how are those figures calculated? Why are there such differences in the results from one company to another? This presentation provides insights on how these percentages are derived.
Ancestral Percentages here meaning Biogeographical Ancestry (BGA) defined as an estimation of one’s biological, ethnic and/or geopgrahical origins based on DNA analysis.
- Also know as Ethnicity Estimates, Admixture Analysis, etc.
- Being mass marketed on television and other media as
“Holy Cow, I found out I was 35% Martian and 25% Imaginerian?”
- Currently the most common basis that Ancestral Percentages are being calculated is with Microarray DNA sequencers that test about 600,000 to 1 million known SNP (single nucleotide polymorphism) markers very quickly and inexpensively.
Here is a list of references, resources, and additional information relating to the presentation for Insights on DNA Ancestral Percentages:
- Online PDF version of presentation slides Insights on DNA Ancestral Percentages Presentation 2018
ISOGG Wiki – Biogeographical Ancestry
Human Genome Assembly GRCh38p12:
Family Tree DNA White Paper on MyOrigins version 2 (2014, Updated 2017):
Your Genetic Genealogist, Comparing Admixture Test Results Across Companies
Cruwys news, Three Generations of FTDNA MyOrigins 2.0 results from Family Tree DNA
Behar et al (2012), A “Copernican” Reassessment of the Human Mitochondrial DNA Tree from its Root https://doi.org/10.1016/j.ajhg.2012.03.002
Ancestry.com Ethnicity Estimate White Paper (2013)
Heat Map of Chromosome Coverage by Ancestry V2 Chip Across 23 Chromosomes by Rebekah Canada
- 23andMe Ancestry Composition Guide (V5 chip)
- 23andMe White Paper 16-23 (V4), Durand et al (2014), Ancestry Composition: A Novel, Efficient Pipeline for Ancestry Deconvolution
dbSNP – National Institute of Health, Reference for Short Genetic Variations
Pritchard et al (2000), Inference of Population Structure Using Multilocus Genotype Data
- Raj, Stephens, Pritchard (2013), Variational Inference of Population Structure in Large SNP Datasets http://dx.doi.org/10.1101/001073
- 1000 Genomes Project
http://www.internationalgenome.org/about/ European Bioinformatics Institute
- ISOGG Wiki – History of Genetic Genealogy
- Ce Ce Moore, Your Genetic Genealogist
- Roberta Estes, DNAeXplained, Autosomal Testing Company Results
Gregory D. Smithers, Slate Magazine, Why Do So Many Americans Think They Have Cherokee Blood?
- Steven R Anderson, Linguistic Society of America, How many languages are there in the world?