Problems of Forensic Sciences 1999 Vol. 39 (XXXIX) 103-121
POPULATION DIFFERENTIATION AND THE VALUE OF DNA EVIDENCE
Paulina WOLAŃSKA-NOWAK
Institute of Forensic Research, Cracow
Streszczenie
The strength of any evidence can be assessed using a likelihood ratio (from Bayes' point of view). This is the ratio of the probabilities that the evidence would have been obtained given that the suspect is guilty and innocent, respectively. This, in turn, depends upon the probability that a match will be produced if the suspect is innocent. A key population genetics parameter is the " coancestry coefficient" , or q , or FST, which is the correlation between two genes sampled from distinct individuals within a subpopulation. In this paper q coefficients for Polish population were calculated in four loci. The results suggest that values of q appropriate to forensic applications are quite small in the Polish population, and the values of q = 0.01 and even more so q = 0.03 suggested by National Research Council are too conservative for the defendant.
Słowa kluczowe
DNA profiles; Identification; Statistics; Population genetics; Evidence value; Coancestry coefficient.