Stable population structure in Europe since the Iron Age, despite high mobility

Ancient DNA research in the past decade has revealed that European population structure changed dramatically in the prehistoric period (14,000–3000 years before present, YBP), reflecting the widespread introduction of Neolithic farmer and Bronze Age Steppe ancestries. However, little is known about how population structure changed from the historical period onward (3000 YBP - present). To address this, we collected whole genomes from 204 individuals from Europe and the Mediterranean, many of which are the first historical period genomes from their region (e.g. Armenia and France). We found that most regions show remarkable inter-individual heterogeneity. At least 7% of historical individuals carry ancestry uncommon in the region where they were sampled, some indicating cross-Mediterranean contacts. Despite this high level of mobility, overall population structure across western Eurasia is relatively stable through the historical period up to the present, mirroring geography. We show that, under standard population genetics models with local panmixia, the observed level of dispersal would lead to a collapse of population structure. Persistent population structure thus suggests a lower effective migration rate than indicated by the observed dispersal. We hypothesize that this phenomenon can be explained by extensive transient dispersal arising from drastically improved transportation networks and the Roman Empire’s mobilization of people for trade, labor, and military. This work highlights the utility of ancient DNA in elucidating finer scale human population dynamics in recent history

The bony pelvis

Die Theorie hinter der Entstehung und Manifestierung der sogenannten „Scars of Parturition“ und ihre Verwendbarkeit um die Anzahl der Geburten einer Frau zu bestimmen, ist immer noch ein viel diskutiertes Thema unter AnthropologInnen. Aufgrund inkonsistenter Ergebnisse bisheriger Studien konnte der wahre Zusammenhang zwischen den Beckenmerkmalen, die als Indikatoren für Schwangerschaft und Geburt gelten, und Gravidität und Partus noch nicht gezeigt werden. Skelettsammlungen mit bekannter Geburtsgeschichte der weiblichen Individuen sind rar. Deshalb ist eine Untersuchung anderer potentieller Faktoren, welche die Entstehung und Manifestierung der Beckenmerkmale beeinflussen könnten, die beste Herangehensweise um diese spezifischen Merkmale zu analysieren. Das Ziel dieser Studie war es, die Morphologie und die Häufigkeit der Beckenmerkmale, nämlich die dorsalen Schamgruben, das Tuberculum pubicum und der Sulcus praeauricularis, an einer Skelettsammlung der Universität Vilnius von 300 Individuen (170 Männer und 130 Frauen) zu untersuchen. Zudem wurde nach standardisierten Methoden Beckendimensionen gemessen und das Körpergewicht ermittelt. Die Beckenmerkmale, die Beckendimensionen und das Körpergewicht wurden entsprechend dem Geschlecht und dem Alter der Individuen verglichen. Weiters wurde der Zusammenhang zwischen den Beckenmerkmalen und den Beckendimensionen, sowie dem Körpergewicht untersucht. Die statistische Analyse zeigte, dass die Beckenmerkmale sowohl bei Frauen, als auch Männern vorkommen. Der Ausprägungsgrad und das Vorkommen waren jedoch stärker im weiblichen Geschlecht anzutreffen. Die Merkmale wurden in allen Altersgruppen gefunden, allerdings erhöhte sich bzw. blieb die Häufigkeit und die Manifestierung konstant bei steigendem Alter. Die Korrelation zwischen den Beckenmerkmalen und den Beckendimensionen zeigte einen signifikant positiven Zusammenhang, sowohl zwischen der Pubislänge und dem Durchmesser des Tuberculum pubicums, als auch zwischen der Distantia interspinosa und der Tuberculumhöhe bei den Frauen. Weiters wurde ein signifikant negativer Zusammenhang zwischen dem Abstand der Spinae ischiadicae und der Extension des Tuberculum pubicums, sowie zwischen der Pubislänge und der Breite des Sulcus praeauricularis im weiblichen Geschlecht gefunden. Das Körpergewicht korrelierte negativ mit der Höhe des Tuberculums und der Sulcuslänge und Sulcusbreite bei Frauen. In der jüngsten Altersgruppe zeigte sich ein positiver Zusammenhang zwischen dem Körpergewicht und der Länge der Schamgruben, während bei den mittleren Adulten das Körpergewicht negativ mit der Sulcuslänge und Sulcusbreite korrelierte. Die Ergebnisse legen nahe, dass Schwangerschaft und Geburt nicht primär für die Entstehung der spezifischen Beckenmerkmale verantwortlich sind. Das Körpergewicht beeinflusste ihre Formation ebenfalls nicht wesentlich. Stattdessen könnte die Architektur und die gewichtstragende Funktion des knöchernen Beckens in erster Linie zur Entstehung und Manifestierung der Beckenmerkmale beigetragen haben. Der flexible Beckengürtel bei Frauen führt zu einer erhöhten Bewegungsfreiheit. Dadurch werden die Ligamente des Beckens stärker belastet und somit führt dies zur Entstehung dieser spezifischen Beckenmerkmale.The theory behind the formation and manifestation of the so-called „scars of parturition“ and particularly their possible use in determining parity history is still a debated issue among anthropologists. In spite of large amounts of studies, the results are in part contradictory and hence, a true relationship between the pelvic scars and pregnancy and childbirth could not be conclusively shown yet. Since skeletal collections with information about the parity history of female individuals are rare, the best approach is to investigate the relationship of scarring with other potential factors influencing its formation and manifestation. The aim of the present study was to measure and observe the variability of morphology and frequency of the parturition scars, namely the dorsal pubic pits, the pubic tubercle, and the preauricular sulcus, in a Lithuanian skeletal collection provided by the University of Vilnius comprising 170 males and 130 females. The body mass was estimated and measurements of the pelvic girdle were taken. The pelvic scars, pelvic dimensions, and body mass estimates were compared according to sex and age at death. Further, the relationship between scarring, pelvic measurements, and body mass was examined. The statistical analysis showed that pelvic scarring was present in both sexes, however, the degree and frequency was significantly greater in females. The scar features were also found among all age groups, whereby the incidence and manifestation of the imprints either increased or remained unchanged with advancing age. The correlation test revealed a significant positive relationship between pubic length and pubic tubercle diameter and the anterior upper spinal breadth and the tubercle height in females. A significant negative association was found between the distance of the ischial spines and the extension of the pubic tubercle and the pubic length and sulcus width in women. Body mass correlated significantly negatively with the tubercle height, sulcus length and sulcus width in the female sample. In the youngest age group, the body mass estimate showed a positive relationship with pit length, whereas in middle-aged adults it was negatively correlated with the preauricular sulcus length and width. The results indicate that pregnancy and childbirth cannot be the primary factors that cause pelvic scarring. Also, body mass does not affect scar formation substantially. Instead, pelvic architecture and the weight-bearing function of the pelvis might contribute primarily to its formation. Females exhibit a more flexible pelvic girdle with greater mobility, which increases the strain acting on the pelvic ligaments and hence, causes scar formation

Metric and morphological analysis of pelvic scars in a historical sample from Lithuania: associations with sex, age, body size and pelvic dimensions

The theory behind the formation and manifestation of pelvic scars, sometimes called “scars of parturition”, and particularly their potential use in determining parity history has been a debated issue among anthropologists for nearly 50 years. To date, the association between parity and scar formation still remains unclear. The present study tests the effects of sex, age, body size and pelvic dimensions on the morphological and metric features of dorsal pits, pubic tubercle and preauricular sulcus. 296 skeletons (167 males, 129 females) from historical samples in Lithuania were examined. Beyond assessing the above traits of these pelvic scars, we determined sex, age at death and pelvis dimensions. Moreover, we reconstructed body height and body mass. A marked sexual dimorphism was recorded. Scar formation was significantly more common among females. With increasing age, scar formation increased or remain unchanged. Pelvic dimensions, body height and body mass showed a weak association with pelvic scars. Sex seems to be independently associated with scar formation. Our results suggest that although sex plays a dominant role in scar formation, caution should be exercised in interpreting scars as being due solely to parity alone. The term “scars of parturition” should be avoided

Stable population structure in Europe since the Iron Age, despite high mobility

Ancient DNA research in the past decade has revealed that European population structure changed dramatically in the prehistoric period (14,000-3000 years before present, YBP), reflecting the widespread introduction of Neolithic farmer and Bronze Age Steppe ancestries. However, little is known about how population structure changed from the historical period onward (3000 YBP - present). To address this, we collected whole genomes from 204 individuals from Europe and the Mediterranean, many of which are the first historical period genomes from their region (e.g. Armenia and France). We found that most regions show remarkable inter-individual heterogeneity. At least 7% of historical individuals carry ancestry uncommon in the region where they were sampled, some indicating cross-Mediterranean contacts. Despite this high level of mobility, overall population structure across western Eurasia is relatively stable through the historical period up to the present, mirroring geography. We show that, under standard population genetics models with local panmixia, the observed level of dispersal would lead to a collapse of population structure. Persistent population structure thus suggests a lower effective migration rate than indicated by the observed dispersal. We hypothesize that this phenomenon can be explained by extensive transient dispersal arising from drastically improved transportation networks and the Roman Empire's mobilization of people for trade, labor, and military. This work highlights the utility of ancient DNA in elucidating finer scale human population dynamics in recent history

Low digit ratio (2D:4D) is associated with early natural menopause

Objectives: Intrauterine environmental conditions may affect the number of primordial follicles and in this way the timing of menopause. The aim of the present study was to investigate association patterns between right hand digit ratio, that is, 2D:4D - as an indicator of prenatal androgen and estrogen expo- sure, and age at menopause. Methods: One hundred sixty-nine women, who had experienced natural menopause, were enrolled in the study. Length of second and fourth finger were measured directly from the palmar side and digit ratios of both hands were calculated. For further analyses the digit ratio of the right hand was used only. Additionally, smoking habits, body weight and body height, body mass index and the number of children were determined. Multiple regression ana- lyses were used to test association patterns between digit ratio and age at men- opause, body height, BMI, nicotine consumption as well as number of births and age at menopause. Results: Age at menopause correlated significantly positively with the digit ratio. A more feminine digit ratio is associated with a higher age at meno- pause, while a low digit ratio, interpreted as a hint of a higher androgen expo- sure during prenatal phase was associated with a lower age at menopause. Conclusions: Low digit ratio is associated with an earlier onset of natural menopause.© 2019 The Author

Stable population structure in Europe since the Iron Age, despite high mobility

International audienceAncient DNA research in the past decade has revealed that European populationstructure changed dramatically in the prehistoric period (14,000–3000 years before present, YBP),reflecting the widespread introduction of Neolithic farmer and Bronze Age Steppe ancestries.However, little is known about how population structure changed from the historical period onward(3000 YBP - present). To address this, we collected whole genomes from 204 individuals fromEurope and the Mediterranean, many of which are the first historical period genomes from theirregion (e.g. Armenia and France). We found that most regions show remarkable inter-individualheterogeneity. At least 7% of historical individuals carry ancestry uncommon in the region wherethey were sampled, some indicating cross-Mediterranean contacts. Despite this high level ofmobility, overall population structure across western Eurasia is relatively stable through the historicalperiod up to the present, mirroring geography. We show that, under standard population geneticsmodels with local panmixia, the observed level of dispersal would lead to a collapse of populationstructure. Persistent population structure thus suggests a lower effective migration rate than indi-cated by the observed dispersal. We hypothesize that this phenomenon can be explained by exten-sive transient dispersal arising from drastically improved transportation networks and the RomanEmpire’s mobilization of people for trade, labor, and military. This work highlights the utility ofancient DNA in elucidating finer scale human population dynamics in recent history