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We report on the use of rare mutations to tackle biosocial questions such as kinship and differential burial practices from past human populations. To do this, we have inferred nucleotide position 73 of HVS-II in individuals classified as belonging to haplogroup H from 76 human dental samples from the necropolis of Aldaieta (Basque Country, Spain, 6th-7th century) by means of PCR and restriction enzyme tests. The same analysis has been performed for 146 extant individuals from the northern Iberian peninsula. A combination of haplotype H and 73G in HVS-II, rare in extant populations (0.5-3%), has been found at a frequency of 20% in the ancient population of Aldaieta. These data can be explained in terms of the existence of different burial practices associated with a variety of factors, mainly social status and kinship. This hypothesis is also supported by archeological data. These results indicate that caution should be taken when making phylogenetic inferences from extinct populations, because an uncharacterized kinship can significantly bias allele frequencies. [ABSTRACT FROM AUTHOR]

We report the results of Spanish and Portuguese working group (GEP) of International Society of Forensic Genetics (ISFG) Collaborative Exercise 2001–2002 on mitochondrial DNA (mtDNA) analysis. 64 laboratories from Spain, Portugal and several Latin-American countries participated in this quality control exercise. Five samples were sent to the participating laboratories, four blood stains (M1–M4) and a sample (M5) consisting of two hair shaft fragments. M4 was non-human (Felis catus) in origin; therefore, the capacity of the labs to identify the biological source of this sample was an integral part of the exercise. Some labs detected the non-human origin of M4 by carrying out immuno-diffussion techniques using antihuman serum, whereas others identified the specific animal origin by testing the sample against a set of animal antibodies or by means of the analysis of mtDNA regions (Cyt-b, 12S, and 16S genes). The results of the other three human blood stains (M1–M3) improved in relation to the last Collaborative Exercises but those related to hairs yielded a low rate of success which clearly contrasts with previous results. As a consequence of this, some labs performed additional analysis showing that the origin of this low efficiency was not the presence of inhibitors, but the low quantity of DNA present in these specific hair samples and the degradation.As a general conclusion the results emphasize the need of external proficiency testing as part of the accreditation procedure for the labs performing mtDNA analysis in forensic casework. [Copyright &y& Elsevier]