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I thought pedigree was for dogs…

            Genetic pedigrees are used to trace a family’s genetic history. This allows people to deduce most- if not all- of their ancestors’ genotypes for particular traits based on; those who expressed the trait in their phenotype, those who did not, and whether or not their children expressed the trait as well.

How it works:

Knowing that a person who expressed a recessive trait (rr) married someone who didn’t express that trait (R?) and had a child who also expressed the recessive trait (rr) you can figure out that the father must have been heterozygous (Rr) or their child could not have been homozygous recessive.
                                                                                                   What else do Pedigrees do?

            Using family pedigrees spouses can find the probabilities of their children getting a certain trait. A pedigree doubles as a family tree which is great for looking at one’s ancestry. A drawback to pedigrees is that it can be impossible to know a person’s genotype if there isn’t enough information to know for sure. Pedigrees do however give insight to whether or not a disorder is recessive or dominant based on the  inheritance patterns shown throughout a family's history.

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