233 research outputs found
Timing the first human migration into eastern Asia
A recent report in BMC Biology indicates that modern humans first arrived in southern East Asia 60,000 years ago and settled the rest of East Asia from there. This early date and migration route has significant implications for our understanding of the origins of present-day human populations
On the edge of Bantu expansions: mtDNA, Y chromosome and lactase persistence genetic variation in southwestern Angola
Meta-Analysis of a New Georeferenced Database on Polycyclic Aromatic Hydrocarbons in Western and Central Mediterranean Seafood
The aim of this work was to collect and harmonize the results of several studies achieved
over the years, in order to obtain a database of georeferenced observations on polycyclic aromatic
hydrocarbons (PAHs) in Western and Central Mediterranean seafood. For each observation, some
information on the taxonomy and the ecology of the sampled species are reported, as well as details
on the investigated hydrocarbon, and spatial and temporal information on sampling. Moreover,
two health risk indexes were calculated for each record and included in the database. Through
several statistical methods, we conducted a meta‐analysis of the data on some of the species in this
database, identifying trends that could be related to the biology of the investigated organisms, as
well as to the physico‐chemical properties of each hydrocarbon and to the oceanographic
characteristic of this part of the Mediterranean. The analysis of the data showed that, at a
consumption rate like the one typical of the Italian population, seafood caught from the area
considered in the present work seems to pose a minimal risk to health. However, we also found
evidence of an increasing trend of PAH concentrations in Mediterranean mussels, pointing to the
need for constant monitoring
Mitochondrial DNA Diversity in South America and the Genetic History of Andean Highlanders
We analyzed mtDNA sequence variation in 590 individuals from 18 south Amerindian populations. The spatial pattern of mtDNA diversity in these populations fits well the model proposed on the basis of Y-chromosome data. We found evidence of a differential action of genetic drift and gene flow in western and eastern populations, which has led to genetic divergence in the latter but not in the former. Although it is not possible to identify a pattern of genetic variation common to all South America, when western and eastern populations are analyzed separately, the mtDNA diversity in both regions fits the isolation-by-distance model, suggesting independent evolutionary dynamics. Maximum-likelihood estimates of divergence times between central and south Amerindian populations fall between 13,000 and 19,000 years, which is consistent with a Pleistocenic peopling of South America. Moreover, comparison of among-population variability of mtDNA and Y-chromosome DNA seems to indicate that South America is the only continent where the levels of differentiation are similar for maternal and paternal lineages
The plague of 1630 in Modena (Italy) through the study of parish registers
The purpose of this paper is to study the impact this disease had on the community in Modena during the epidemic in 1630 and highlight the real course of the disease that brought Modena and whole Europe to its knees in the 17th century. The investigation was carried out by transcribing and studying the par-ish certificates of death for the period 1625-1635. This study confirmed that the plague epidemic in Modena began as early as 1629, and then exploded in the most virulent form since the beginning of summer 1630 and reached its peak in August of the same year, when it caused about seven hundred victim
On the Origins and Admixture of Malagasy: New Evidence from High-Resolution Analyses of Paternal and Maternal Lineages
The Malagasy have been shown to be a genetically admixed population combining parental lineages with African and South East Asian ancestry. In the present paper, we fit the Malagasy admixture history in a highly resolved phylogeographic framework by typing a large set of mitochondrial DNA and Y DNA markers in unrelated individuals from inland (Merina) and coastal (Antandroy, Antanosy, and Antaisaka) ethnic groups. This allowed performance of a multilevel analysis in which the diversity among main ethnic divisions, lineage ancestries, and modes of inheritance could be concurrently evaluated. Admixture was confirmed to result from the encounter of African and Southeast Asian people with minor recent male contributions from Europe. However, new scenarios are depicted about Malagasy admixture history. The distribution of ancestral components was ethnic and sex biased, with the Asian ancestry appearing more conserved in the female than in the male gene pool and in inland than in coastal groups. A statistic based on haplotype sharing (D(HS)), showing low sampling error and time linearity over the last 200 generations, was introduced here for the first time and helped to integrate our results with linguistic and archeological data. The focus about the origin of Malagasy lineages was enlarged in space and pushed back in time. Homelands could not be pinpointed but appeared to comprise two vast areas containing different populations from sub-Saharan Africa and South East Asia. The pattern of diffusion of uniparental lineages was compatible with at least two events: a primary admixture of proto-Malay people with Bantu speakers bearing a western-like pool of haplotypes, followed by a secondary flow of Southeastern Bantu speakers unpaired for gender (mainly male driven) and geography (mainly coastal)
A Mitochondrial Haplogroup is Associated with Decreased Longevity in a Historic New World Population
Interest in mitochondrial influences on extended longevity has been mounting, as demonstrated by a growing literature. Such work has demonstrated that some haplogroups are associated with increased longevity and that such associations are population-specific. Most previous work however, suffers from the methodological shortcoming that long-lived individuals are compared with “controls” who are born decades after the aged individuals were. The only true controls of the elderly are people who were born on the same time period, but who did not have extended longevity. Here we present results of a study in which we are able to test if longevity is independent of haplogroup type, controlling for time period, by using mitochondrial DNA genealogies. Since mtDNA does not recombine, we know the mtDNA haplogroup of the maternal ancestors of our living participants. Therefore, we compare the haplogroup of people with and without extended longevity, who were born during the same time period. Our sample is an admixed New World population which has haplogroups of Amerindian, European and African origin. We show that women who belong to Amerindian, European and African haplogroups do not differ in their mean longevity. Therefore, to the extent that ethnicity was tied in this population to mtDNA make up, such ethnicity did not impact longevity. In support of previous suggestions that the link between mtDNA haplogroups and longevity is specific to the population being studied, we found an association between haplogroup C and decreased longevity. Interestingly, the lifetime reproductive success and the number of grandchildren produced via a daughter of women with haplogroup C are not reduced. Our diachronic approach to the mtDNA and longevity link allowed us to determine that the same haplogroup is associated with decreased longevity during different time periods, and allowed us to compare the haplogroup of short and long-lived individuals born during the same time period. By controlling for time period, we minimize the effect of different cultural and ecological environments on differential longevity. With our diachronic approach, we investigate the mtDNA and longevity link with a biocultural perspective
Epigenetic Variability across Human Populations: A Focus on DNA Methylation Profiles of the KRTCAP3, MAD1L1 and BRSK2 Genes
Natural epigenetic diversity has been suggested as a key mechanism in microevolutionary processes due to its capability to create phenotypic variability within individuals and populations. It constitutes an important reservoir of variation potentially useful for rapid adaptation in response to environmental stimuli. The analysis of population epigenetic structure represents a possible tool to study human adaptation and to identify external factors that are able to naturally shape human DNA methylation variability. The aim of this study is to investigate the dynamics that create epigenetic diversity between and within different human groups. To this end, we first used publicly available epigenome-wide data to explore population-specific DNA methylation changes that occur at macro-geographic scales. Results from this analysis suggest that nutrients, UVA exposure and pathogens load might represent the main environmental factors able to shape DNA methylation profiles. Then, we evaluated DNA methylation of candidate genes (KRTCAP3, MAD1L1, and BRSK2), emerged from the previous analysis, in individuals belonging to different populations from Morocco, Nigeria, Philippines, China, and Italy, but living in the same Italian city. DNA methylation of the BRSK2 gene is significantly different between Moroccans and Nigerians (pairwise t-test: CpG 6 P-value = 5.2*10 (-) (3); CpG 9 P-value = 2.6*10 (-) (3); CpG 10 P-value = 3.1*10 (-) (3); CpG 11 P-value = 2.8*10 (-) (3)). Comprehensively, these results suggest that DNA methylation diversity is a source of variability in human groups at macro and microgeographical scales and that population demographic and adaptive histories, as well as the individual ancestry, actually influence DNA methylation profiles
Ethnicity and Biodemographic Structure in the Arbëreshe of the Province of Cosenza, Southern Italy, in the XIX Century
Cultural and environmental factors interact in determining the genetic structure of human populations. Bio-demographic
investigations of ethnic minorities are able to disentangle the influences that these two components have on the
evolution of the genetic structure of a population. The ethnic minority of the Arbëreshe of the province of Cosenza (Calabria,
southern Italy) is analyzed in this paper and its bio-demographic structure in the early 1800s is compared with that
of neighboring Italian populations. The data derive from surnames recorded in the birth registers of the 19 Arbëreshe
municipalities of the province of Cosenza and in 5 non-Arbëreshe municipalities of the same province. Isonymy and repeated
pairs of surnames are used to analyze the bio-demographic structure of these populations, while analysis of isonymic
relationships is used to investigate the variability between populations. Higher values of marital isonymy and subdivision
into subpopulations characterize the Arbëreshe populations with respect to their non-Arbëreshe neighbors. However,
the high range of variability of these parameters suggests a strong influence of geographic location on the marriage pattern
of each community. At the same time, cultural differences linked to group identity had a strong impact in limiting
marriage exchanges between the different ethnic groups living in the province of Cosenza in the early 1800s. In fact, the
analysis of isonymic relationships demonstrates that geographic location shaped kinship patterns among the Arbëreshe
communities, but it also shows that the non-Arbëreshe neighbors formed a clearly separate reproductive cluster
Paleopathological Approach to the Study of a Christian Relic: The Case of the Blessed Maria Lorenza Longo
The Blessed Maria Lorenza Longo, founder of the hospital of Santa Maria del Popolo degli Incurabili and the Order of the Capuchin Poor Clares in Naples, Italy, died on 21 October 1539 and was recently beatified on 9 October 2021. The relic, a fully skeletonized cranium, underwent visual and radiological inspection. The biological profile supports the at¬tribution of female sex of the relic, whereas the age at death is estimated to be younger than that reported by historians. A paleopathological survey was conducted to evaluate the historical reports of poisoning or rheumatoid arthritis affecting Maria Longo. Given the limited skeletal data, it was not possible to confirm the presence of these claims. No obvious in¬dicators of dietary deficiencies were observed, and the tertiary syphilis hypothesized by textual sources was excluded. Postmortem alterations of the relic were clearly visible on the superior aspect of the cranium and testified to the worship of the relic
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