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更多“家谱，又称族谱、宗谱等。是一种以表谱形式，记载一个家族的世系…”相关的问题
The main objective of the Molecular Genealogy Research Group is to build a database containing over 100,000 DNA samples from individuals all over the world. These individuals will have provided a pedigree chart of at least four generations and a small blood sample. Once the database has enough samples to represent the world genetic make-up, it will eventually help in solving many issues regarding genealogies that could not be done by relying only on traditional written records. Theoretically, any individual will someday be able to trace his or her family origins through this database.
In the meantime, as the database is being created, molecular genealogy can already verify possible or suspected relationships between individuals. "For example, if two men sharing the same last name believe that they are related, but no written record proves this relationship, we can verify this possibility by collecting a sample of DNA from both and looking for common markers (in this case we can look primarily at the Y chromosome (染色体)," explains George Green, a member of the BYU Molecular Genealogy research team.
People in a large area may possess the same DNA thread because______.
A．DNA is characteristic of a region
B．they are beyond doubt of common ancestry
C．DNA strand has the ability to identify individuals
D．their unique identification can be provided via DNA
