Discussion:
Forensic Science and Allele Repeates
A group of 6 bodies is found buried in the woods, three adult males, one adult female, and two children. They are thought to include a missing family (2 parents and 2 children). DNA is extracted from the skeletal remains and analyzed for two STR markers using PCR. In the results below, the numbers indicate the number of tandem repeats in an allele (e.g., at STR 1 Child 1 has one allele with 7 repeats and one with 8).
STR1 STR2
Male 1 8/9 5/7
Male 2 6/8 5/5
Male 3 7/10 7/7
Female 8/8 3/5
Child 1 7/8 5/7
Child 2 8/8 3/7
A) Could the female have been the mother of both the children? Why or why not?
B) Which male, if any, is the father of Child 1?
C) Does Child 2 have the same father? Why or why not?