BCG DNA & Genetic Genealogy Flashcards

What is 'endogamy' and why does it complicate genetic genealogy research?

Answer: A pattern of marrying within a community, causing individuals to share DNA from multiple lines rather than a single common ancestor

Endogamy causes individuals to share elevated amounts of DNA from multiple ancestral paths, making it difficult to isolate specific genealogical relationships.

What is the role of mitochondrial DNA (mtDNA) in genealogical research?

Answer: It traces the direct maternal line and is passed virtually unchanged from mother to child

Mitochondrial DNA is inherited maternally with minimal change, making it useful for tracing the direct maternal line across many generations.

In a BCG portfolio, how must a genealogist present DNA evidence used to support a kinship conclusion?

Answer: Integrated into the narrative with full citations, analysis of the relationship prediction, and correlation with other evidence

BCG requires DNA evidence to be fully integrated into the written narrative with citations, relationship analysis, and correlation with documentary sources.

What is 'identical by descent' (IBD) versus 'identical by state' (IBS) in genetic genealogy?

Answer: IBD refers to segments inherited from a common ancestor; IBS refers to segments that appear identical by chance or population patterns

IBD segments are genuinely inherited from a shared ancestor, while IBS segments appear identical due to coincidence or shared population background rather than direct genealogical descent.

Which tool or method helps a researcher determine whether a DNA match relates to the maternal or paternal side when parents are not available for testing?

Answer: Shared match analysis and clustering

Analyzing shared matches and clustering them by known relatives on each side helps assign unidentified matches to the maternal or paternal line.

How does the BCG's Genealogical Proof Standard apply specifically to genetic genealogy conclusions?

Answer: The GPS requires reasonably exhaustive research, complete citations, analysis of all evidence, resolution of conflicts, and a soundly reasoned written conclusion — applicable to DNA-based claims as well

The GPS applies universally; DNA-based genealogical conclusions must meet all five elements including exhaustive research, full citations, evidence correlation, conflict resolution, and a written proof argument.