Recently, the debate on the origins of the major European Y chromosome haplogroup R1b1b2-M269 has reignited, and opinion has moved away from Palaeolithic origins to the notion of a younger Neolithic spread of these chromosomes from the Near East. Here, we address this debate by investigating frequency patterns and diversity in the largest collection of R1b1b2-M269 chromosomes yet assembled. Our analysis reveals no geographical trends in diversity, in contradiction to expectation under the Neolithic hypothesis, and suggests an alternative explanation for the apparent cline in diversity recently described. We further investigate the young, STR-based time to the most recent common ancestor estimates proposed so far for R-M269-related lineages and find evidence for an appreciable effect of microsatellite choice on age estimates. As a consequence, the existing data and tools are insufficient to make credible estimates for the age of this haplogroup, and conclusions about the timing of its origin and dispersal should be viewed with a large degree of caution.

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The role of DNA damage in PCR processivity/fidelity is a relevant topic in molecular investigation of aged/forensic samples. In order to reproduce one of the most common lesions occurring in postmortem tissues, a new protocol based on aqueous hydrolysis of the DNA was developed in vitro. Twenty-five forensic laboratories were then provided with 3.0 μg of a trial sample (TS) exhibiting, in mean, the loss of 1 base of 20, and a molecular weight below 300 bp. Each participating laboratory could freely choose any combination of methods, leading to the quantification and to the definition of the STR profile of the TS, through the documentation of each step of the analytical approaches selected. The results of the TS quantification by qPCR showed significant differences in the amount of DNA recorded by the participating laboratories using different commercial kits. These data show that only DNA quantification "relative" to the used kit (probe) is possible, being the "absolute" amount of DNA inversely related to the length of the target region (r(2) = 0.891). In addition, our results indicate that the absence of a shared stable and certified reference quantitative standard is also likely involved. STR profiling was carried out selecting five different commercial kits and amplifying the TS for a total number of 212 multiplex PCRs, thus representing an interesting overview of the different analytical protocols used by the participating laboratories. Nine laboratories decided to characterize the TS using a single kit, with a number of amplifications varying from 2 to 12, obtaining only partial STR profiles. Most of the participants determined partial or full profiles using a combination of two or more kits, and a number of amplifications varying from 2 to 27. The performance of each laboratory was described in terms of number of correctly characterized loci, dropped-out markers, unreliable genotypes, and incorrect results. The incidence of unreliable and incorrect genotypes was found to be higher for participants carrying out a limited number of amplifications, insufficient to define the correct genotypes from damaged DNA samples such as the TS. Finally, from a dataset containing about 4500 amplicons, the frequency of PCR artifacts (allele dropout, allele drop-in, and allelic imbalance) was calculated for each kit showing that the new chemistry of the kits is not able to overcome the concern of template-related factors. The results of this collaborative exercise emphasize the advantages of using a standardized degraded DNA sample in the definition of which analytical parameters are critical for the outcome of the STR profiles.

In cases of rape, obtaining enough biologic material for DNA identification of the attacker is often difficult because the methods for distinguishing and separating sperm cells from vaginal cells are not sufficiently efficacious. This article describes a new, innovative method for spermatic DNA extraction from the vaginal washing fluid by means of flow cytometry. The high specificity and sensitivity of the flow-cytometric sorting method provides enough sperm cells for DNA typing. The ease of execution of this method, involving vaginal washing with physiologic solution and flow-cytometric reading of the fresh sample, substantially increases its cost-benefit ratio.

In forensic entomology, insects are used mainly to obtain information about the time since death. This information is obtained studying the developmental rate of the first colonizers, principally species in the families Calliphoridae, Sarcophagidae, Muscidae, Stratiomyidae and Phoridae. However, species belonging to other families can provide information about body transfer or the season of the death. Among them Milichiidae are flies rarely reported from human cases despite the larvae of some species are known as saprophagous feeding on plant and animal decomposing matter. A potential cause of the lack of records of these species from forensic cases can be related with the paucity of descriptions and illustrations of the immature stages. In this article, the entomological samples collected from a human body found inside an apartment in a Maghreb country, in Northern Africa, is reported and Leptometopa latipes (Diptera: Milichiidae) is described in detail. Molecular analysis is also reported to confirm the morphological analysis. ARTICLE HISTORY

The present study examines a case in which signs of incised wounds were found on skeletal remains of a murder victim. The authors have studied the skeletal remains and the dynamics of the murder in order to reconstruct the kind of weapon utilized. The bones examined belonged to a woman that had disappeared from almost 10 years and where recovered from the garden of the house belonging to her former partner. The main feature of these remains was the discovery of a damage of a thoracic vertebra (T1). Our examination has the objective to enhance the macroscopic analysis of the skeletal remains in order to deduce information about the classification of specific damages and the dynamics that have caused them and the identification of the weapon that had been used. Highly decomposed bodies, as in skeletal remains, having poor or absent biological tissue on it, challenge the operator to classify the exact nature of the damage, and in some cases, it does not allow achieving a significant level of certainty. In order to solve this critical situation, Forensic Anthropology may contribute greatly by supplying a great amount of information that would not be deciphered otherwise. The bone, main study object of the Forensic Anthropology, may also register, as the soft tissues, the features of the damaging pattern. The opportunity to extrapolate this kind of data, allows analysing the dynamics and the nature of the kind of weapon used. In certain cases the incised bone present also features that allow to identify the exact structure of the weapon: of course, not every wound damages the bone, but when this actually happens, the morphological appearance of the instrument utilized remains crystallized in time, excluding of course the cases in which the bones are destroyed. Many other studies, concerning the characterization of lesions due to sharp objects, have been done and a review of related literature has been included in this article. The major goal of the authors is to highlight the importance of the information that can be extrapolated: the usefulness of the classification of the weapons used to provoke the lesion, could reach a more accurate evaluation in order to significantly help in case of forensic assessment.

Today DNA analyses represent a method of exceptional importance for the resolution of judicial cases. On the one hand, they allow courts to secure criminal convictions, while on the other hand they can help exonerate innocent suspects. Unfortunately, DNA analyses are often considered an unbeatable and infallible method to discover the truth, with the consequence that judges feel forced either to “bow to science” or to totally refuse the genetic evidence when it is considered too complex. On the contrary, genetic investigations have limits that must always be considered and properly explained to the fact-finder by the forensic geneticist. Courts need to know what results were observed and how likely it is to observe such results under both the prosecution and defense hypotheses. This may be particularly challenging for low quantity, degraded or mixed genetic material, and is further complicated by the need to take into account the potential of (laboratory) error. Despite such circumstances, the evidence can still be informative although its probative value may be reduced. The murder of British student Meredith Kercher in Perugia (Italy) in 2007 and the case that ensued have highlighted the limits of genetic analyses. Throughout Italy, this case has caused an intense scientific and (through the media) popular debate on the correct application of internationally recommended protocols and procedures as a preliminary quality and reliability guarantee for results presented in court

Blood samples were obtained from selected and unrelated individuals. DNA was extracted with the standard Chelex® 100 (BioRad, Hercules, CA) extraction procedure (1); DNA samples were amplified in a DNA Gene Amp 9700 (Applied Biosystems, Foster City, CA) using 10 ng of template DNA. The amplified products were detected using the Abi Prism 310 Genetic Analyzer (Applied Biosystems, Foster City, CA).