Chapter 23: Evaluation of the Strength of Forensic DNA Profiling Results

Mendelian Genetics Mendel’s First Principle- segregation of

alleles Mendel’s Second Principle- independent

assortment Meiosis- gametes formed▪ 46 23

Diploid: 22 pairs of autosomes and 2 sex chromosomes (XX & XY)

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Inheritance of genes measured using probabilities

Population Genetics: Studies the causes of the observed patterns of genetic variation Allele Frequency Genotype Frequency

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Hardy-Weinberg Principle 1900’s Allows predictions of the genotype

frequencies to be made from the allelic frequencies

Conditions: ▪ Population is large▪ Randomly mating▪ Absent from mutation, migration, and natural

selectionForensic Biology by Richard Li 4

Evaluate the strength of the matchTwo approaches:

Profile Probability

Likelihood Ratio

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