efficacy and optimization of molecular techniques for sexing skeletonized human remains
abstract
forensic anthropologists and bioarchaeologists are often confronted with the problem of
sex determination in poorly preserved, skeletonized, adult, human remains. this thesis
tests the ability o f newly developed dna methods to address this problem. using a blind
research design, four molecular dna techniques - amelogenin, alphoid repeats, sry (sex
determining region o f the y-chromosome) and y-strs (short tandem repeats) - are
assessed for their ability to determine the sex o f 19 skeletons with known morphological
and/or documented sex. the skeletons represent both historic and ancient human
remains. the latter are from a roman cemetery in the dakhleh oasis, egypt (n=13),
while the former are from historic 19^'’ century cemeteries in london, ontario (n=4) and
thunder bay, ontario (n=l); as well as, an unidentified skeleton fi*om a forensic cold
case (cfs file # a-475-95).
it was hypothesized that the alphoid repeat technique should yield the best results
due to their position near the chromosomal ends and the nature o f dna degradation. the
results show that although the alphoid repeats typed for all but one sample, the
amelogenin had a superior performance, especially for the historic samples. the sry
method was very poor, appearing for only two samples, and the y-str method did not
yield amplification at all. the latter was unexpected and disappointing, because it ystrs
have the potential to aid in male individuation in addition to its inherent ability to
identify sex. the implications for both forensic and bioarchaeological research are far
reaching.
based on the data from this thesis, two important conclusions emerge. the first is
that the results of the amelogenin locus on 100-year-old samples are encouraging. this shows that even in samples with relatively high degradation, the sex o f an individual is
still ascertainable and this is important for forensics, especially where cold cases are
concerned. the second conclusion is that more research is definitely required given the
poor performance o f the alphoid repeat and y-str methods. these include studies to
determine more stringent contamination checks, such as mtdna sequencing o f all
samples yielding results for ancient dna (adna).
collections
- retrospective theses [1604]