BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Talks.cam//talks.cam.ac.uk// X-WR-CALNAME:Talks.cam BEGIN:VEVENT SUMMARY:How should we interpret Y-chromosome evidence? - Bruce Weir (Unive rsity of Washington) DTSTART:20160901T103000Z DTEND:20160901T110000Z UID:TALK67149@talks.cam.ac.uk CONTACT:INI IT DESCRIPTION:Co-author: Taryn Hall (University of Washington)

Although the interpretation of DNA evidence has been discussed e xtensively\, there are still areas where there remains debate on the best methods. One area is for profiles on the Y chromosome\, where the lack o f recombination suggests the locus-specific profiles are not independent. Although an examination of published data demonstrates that many of the loci do have independent profiles\, there are sufficient dependencies tha t there seems little need to continue adding loci to increase discriminat ion: profiles matching at 30 loci are unlikely not to match at the 31st l ocus for example.

Purely statistical approaches break down in pra ctice because most evidential profiles are not represented in profile dat abases. Observed profile frequencies offer little guide to the evidential strength of a Y-chromosome match. We have used both published and simula ted data to evaluate various genetic models that serve as a basis for est imating match probabilities.

Y-chromosome lineages often cr oss geographic or ethnic population boundaries. Genetic models allow pred ictions of the probability that two men\, one of whom is unknown\, will s hare Y-chromosome profiles when they are members of the same or different populations. \; LOCATION:Seminar Room 1\, Newton Institute END:VEVENT END:VCALENDAR