The gene pool of the Belgorod oblast population: changes in the endogamy indices of district populations with time

Changes in the endogamy indices of district populations of the Central Chernozem region of Russia during the past 100 years were studied. The size of an elementary population in this region increased from that of a rural municipality in the mid-20th century to that of an administrative district in the late 20th century.     

Changes in the population of forest and dendrophilous birds of the clay semidesert in the Volga–Ural interfluve over sixty years

The modern situation of the vertebrate population in the clay semidesert of the interfluve of the Volga and Ural rivers differs significantly from that observed 50–60 years ago. This is due to the fact that reduction of ravine forests and steppe shrubs (which began in the 18th century) has extremely affected the forest and dendrophilous animals. The artificial afforestation, especially intense since the middle of the 20th century, provided surrogate “forest” sites in the region by the end of the 1970s. This helped to restore the missing species and raise the abundance and dispersal of forest and dendrophilous animals. By the beginning of the 21st century, afforestation had stopped in the region and the plantation areas had begun to shrink. Some trends in the populations of mammals and birds can be already noticed.     

The long-term development of urban vegetation in Helsinki, Finland: A pollen diagram from Töölönlahti

A core from Töölönlahti, a bay close to the central business district of Helsinki, the capital of Finland, was analysed for its pollen stratigraphy. The extrapolated age-depth curve based on¹³⁷Cs dating, sphaeroidal carbonaceous particle analysis and historical data suggests that the core goes back to the 17th or early 18th century. Four local pollen assemblage zones (LPAZ) were identified. Detrended correspondence analysis was used to detect the main phases of change represented by these zones. The basal LPAZ indicates that the vegetation was characterized by forest dominated byPinus sylvestris andPicea abies during the early history of the city of Helsinki and that human impact remained relatively minor until the end of the 19th century. A drastic change in vegetation took place at the turn of the 19/20th century when bothPinus andPicea declined rapidly while pollen values of several anthropogenic indicators rose. These changes were synchronous with the rapid expansion of population and urban area in Helsinki. Rarefaction analysis shows that palynological richness was highest during the early phase of increased human impact but then started to fall. During the 20th century the main vegetational trend has been the proliferation of introduced park trees. Palynological richness has decreased.     

Recent environmental change in North African wetland lakes: diatom and other stratigraphic evidence from nine sites in the CASSARINA Project

All nine wetland lakes in the CASSARINA North African suite of sample sites have been disturbed strongly by human activity during the 20th century. Dated lake sediment core were used to provide evidence of the extent of recent environmental change at each site. Sedimentary diatoms at seven sites were useful for inferring salinity change trends during the last century. At two sites preservation problems severely degraded the sedimentary diatom record. Sediment core integrity was otherwise established.Lithostratigraphic measurements indicated some site specific changes in soil erosion and sediment composition but, for the Egyptian Delta lakes, no physical signal synchronous with Aswan High Dam construction was found. Sedimentary diatom assemblages were generally site characteristic and halophilous taxa were common. At two sites planktonic diatoms indicated some recent eutrophication but generally the assemblages were more indicative of salinity changes. Diatom-inferred salinity trends for the seven sites typically indicated that reductions in water salinity occurred sometime during the early or mid 20th century.Rather than climate, hydrological modification of water resources is implicated as the primary driver of salinity changes during most of the 20th century. In the western North African region these modifications were mainly local land drainage and water diversion programmes to alleviate winter flooding and/or promote summer water availability. In the Delta region, the Nile has been intensively exploited since antiquity and intensively so from the late 19th century to release more fresh water for agriculture. Here, diatom records indicate that freshening began well before the Aswan High Dam but salinity fluctuations have tended to diminish during the latter part of the 20th century. A small reversal in the water freshening trend in the 1980/90s was possibly a response to land subsidence/sea-level change or to reduced freshwater supply.Freshwater supply to the sites is generally diminishing as former freshwater surpluses switch to deficit. One site (Merja Bokka, Morocco) became completely dry in 1998 as agriculture encroached and Megene Chitane, the only acid lake in Tunisia, is currently affected by excessive inflow abstraction. At the beginning of the 21st century, eight of the nine CASSARINA sites persist as viable but modified aquatic ecosystems. They nevertheless continue to support valuable aquatic biodiversity, especially in the Delta sites and in Chitane. The modern diatom communities are clearly tolerant of considerable environmental change but the remaining sites are increasingly threatened by major hydrological disturbance. Base-line floristic data for the late 20th century are given but continuous biomonitoring combined with effective management is needed urgently to help conserve North Africa's diminishing natural wetland lake resources.     

Rivers Through Time: Historical Changes in the Riparian Vegetation of the Semi-Arid,Winter Rainfall Region of South Africa in Response to Climate and Land Use

This paper examines how the riparian vegetation of perennial and ephemeral rivers systems in the semi-arid, winter rainfall region of South Africa has changed over time. Using an environmental history approach we assess the extent of change in plant cover at 32 sites using repeat photographs that cover a time span of 36–113 years. The results indicate that in the majority of sites there has been a significant increase in cover of riparian vegetation in both the channel beds and adjacent floodplain environments. The most important species to have increased in cover across the region is Acacia karroo. We interpret the findings in the context of historical changes in climate and land use practices. Damage to riparian vegetation caused by mega-herbivores probably ceased sometime during the early 19th century as did scouring events related to large floods that occurred at regular intervals from the 15th to early 20th centuries. Extensive cutting of riparian vegetation for charcoal and firewood has also declined over the last 150 years. Changes in the grazing history as well as increased abstraction and dam building along perennial rivers in the region also account for some of the changes observed in riparian vegetation during the second half of the 20th century. Predictions of climate change related to global warming anticipate increased drought events with the subsequent loss of species and habitats in the study area. The evidence presented here suggests that an awareness of the region’s historical ecology should be considered more carefully in the modelling and formulation of future climate change predictions as well as in the understanding of climate change impacts over time frames of decades and centuries.     

Latest developments of dendro-archaeology in the French Alps: Assessing changes in mountain forests exploitation over the last millennium

Dendrochronological studies are carried out on rural buildings in the French Alps for twenty years. In this contribution, we examine an extensive dataset of larch timbers (n = 1294) that were dendrochronologicaly dated at 139 buildings. This material yielded felling dates spanning the 11th century to the 20th century and contributed to improve our knowledge of human occupation and exploitation of mountain forests during the second millennium CE. From the 11th to the 14th century, rural populations increasingly exploited older forests. The crises of the 14th century led to a significant decrease in construction and by extension in tree cutting. The beginning of the 15th century marks a resumption of construction and felling which is continuous until the beginning of the 20th century. There is a relationship between the age of harvested trees, the number of dates and population fluctuations, which corroborates findings at the European scale. Regional trade probably influenced the stem diameters used in constructions in the immediate vicinity of the forests. Logging regulations can be perceived through variations in the age of harvested trees. The 14th century gap in felling dates would also mark a transition period in the exploitation of mountain forests and by extension a transformation of the economy.     

The history of bronchial asthma from the Renaissance till the beginning of the twentieth century

The aim of the paper is to give an overview of the history of knowledge on asthma from the Renaissance till the beginning of the 20th century. During this period the clinical picture of bronchial asthma and some etiological factors--like familiarity of the disease, the role of the pollen, psychological factors were cleared. The disease was relatively rare in these periods--the epidemiological explosion came only in the second half of the 20th century. Data on pediatric asthma, before all in Hungary are demonstrated mostly based on the works of Schoepf and Bókai senior in the first half of the 19th century.     

Observations on the history of Dutch physical stature from the late-Middle Ages to the present

In the late-Middle Ages and at the onset of the early modern period, the Dutch population was taller than in the first half of the 19th century. This inference is partially based on skeletal evidence, mainly collected by the Dutch physical anthropologist George Maat and his co-workers. A spectacular increase in Dutch heights began in the second half of the 19th century and accelerated in the second half of the 20th century. At the end of the 20th century, the Dutch became tallest in the world.     

On the natural polymorphism of pollen grains of Acer tataricum L.

To study natural polymorphism, pollen grains should be collected from ecologically clean sites. Taking the ecological conditions at the end of the 19th century and at the beginning of the 20th century as more favorable than the modern state, herbarium material (LE) was examined. In addition to typical (normally developed) pollen grains, we found two more morphological types within the range of natural polymorphism of pollen grains of Acer tataricum L. that were produced at the end of the 19th century and at the beginning of the 20th century.     

The Not-so-Dark Ages: ecology for human growth in medieval and early twentieth century Portugal as inferred from skeletal growth profiles

This study attempts to address the issue of relative living standards in Portuguese medieval and early 20th century periods. Since the growth of children provides a good measure of environmental quality for the overall population, the skeletal growth profiles of medieval Leiria and early 20th century Lisbon were compared. Results show that growth in femur length of medieval children did not differ significantly from that of early 20th century children, but after puberty medieval adolescents seem to have recovered, as they have significantly longer femora as adults. This is suggestive of greater potential for catch-up growth in medieval adolescents. We suggest that this results from distinct child labor practices, which impact differentially on the growth of Leiria and Lisbon adolescents. Work for medieval children and adolescents were related to family activities, and care and attention were provided by family members. Conversely, in early 20th century Lisbon children were more often sent to factories at around 12 years of age as an extra source of family income, where they were exploited for their labor. Since medieval and early 20th century children were stunted at an early age, greater potential for catch-up growth in medieval adolescents results from exhausting work being added to modern adolescent's burdens of disease and poor diet, when they entered the labor market. Although early 20th century Lisbon did not differ in overall unfavorable living conditions from medieval Leiria, after puberty different child labor practices may have placed modern adolescents at greater risk of undernutrition and poor growth.     

Maximum June–July temperatures in the southwest Yukon over the last 300 years reconstructed from tree rings

A network of seven high-elevation white spruce tree-ring chronologies from the southwest Yukon is used to reconstruct June–July maximum temperatures (T_max) back to 1684 AD, explaining 46.6% of the climatic variation over the 1946–1995 calibration period. The chronologies are characterised by low interannual ring-width variability and display similar patterns of ring-width variation across the sample area over the last 300 years. The driving force of this common signal appears to be a tree growth response to summer temperatures across the region. The reconstruction compares well with regional records of temperature variability derived from annual ring-width and maximum density data. Periods of cooler temperatures correspond with solar minima and glacier advances, particularly during the early 18th and the early 19th centuries. The maximum reconstructed temperatures are in the 1940s with 20th century values averaging 0.46 °C higher than the 1684–1899 period. In contrast to several regional studies, there does not appear to be a reduction in the sensitivity of tree growth to temperature at these sites during the late 20th century. Instead, a slight increase in the strength of the temperature–tree growth relationship is observed during recent decades. A possible explanation for this difference is the absence of significant summer season warming in the southwest Yukon region in comparison to other areas that have demonstrated this response change. This research is part of an ongoing project aimed at assessing the spatial and temporal potential of dendroclimatic reconstructions from the Yukon Territory.     

History of aquatic invertebrate invasions in the Caspian Sea

Incorporation of the fossil record and molecular markers into studies of biological invasions provides new historical perspectives on the incidence of natural and human-mediated invasions of nonindigenous species (NIS). Palaeontological, phylogeographic, and molecular evidence suggests that the natural, multiple colonizations of the Caspian basin via transient connections with the Black Sea and other basins played an important role in shaping the diversity of Caspian fauna. Geographically isolated, conspecific Ponto-Caspian lineages that currently inhabit fragmented habitats in the Ponto-Caspian region show limited genetic divergence, implying geologically recent episodes of gene flow between populations during the Pliocene to Pleistocene. Several molluscan lineages in the Caspian Sea may have descended from Lake Pannon stock before the Late Miocene isolation of the Caspian depression, about 5.8 million years ago. Anthropogenic activities during the 20th century were responsible for a 1800-fold increase in the rate of establishment of new aquatic species in the Caspian Sea compared to the preceding two million years of natural colonization. The observed success of NIS invasions during the 20th century was due primarily to human-mediated transport mechanisms, which were dominated by shipping activities (44%). Human-mediated species transfer has been strongly asymmetrical, toward the Volga Delta and Caspian Sea from or through Black and Azov Seas. Global and regional trade, particularly that mediated by commercial ships, provides dispersal opportunities for nonindigenous invertebrates, indicating that future invasions in the Caspian Sea are anticipated.     

Adult male height in an American colony: Puerto Rico and the USA mainland compared, 1886–1955

The links between adult height and socioeconomic-political marginality are controversial. We test hypotheses by comparing secular trends between two groups of USA adult male citizens born during 1886-1930: (a) 9805 men surveyed in Puerto Rico during 1965 and (b) 3064 non-Hispanic Whites surveyed on the mainland during 1971-1975. Puerto Rico provides an apt case study because it is the oldest colony in the world and was the poorest region of the USA during the 20th century. During the period considered the average adult man in Puerto Rico was 164.8 cm tall, 8.3 cm shorter than the average adult man on the mainland (173.1cm). Both groups experienced secular improvements in height, with men on the mainland having higher rates than men in Puerto Rico. In neither case were results statistically significant. The modest changes in Puerto Rico likely reflect the offsetting role of improved health and a stagnant rural economy during the first half of the 20th century.     

Climate implications of biomass burning since the 19th century in eastern North America

Recent predictions that tropospheric aerosols have counterbalanced greenhouse warming assume aerosol emissions were low before ad 1850 and then increased dramatically with industrialization of the Northern Hemisphere and biomass burning in the Tropics. We assembled the lake sediment record of emissions across northeastern North America, where temperatures are predicted to have been substantially affected by industrial aerosols. Sediment evidence suggests a systematic shift in source and an overall decline in emissions since the 19th century. The geographical shift results from high presettlement emissions from wildfires in the Midwest that collapsed with tillage and fire suppression. Meanwhile, emissions were increasing in the North-east with European settlement. These regional changes produced a shift from the continental interior to the North-east. An overall decline results because decreases in the Midwest more than compensate for increases in the North-east. Results suggest the Central Plains as an important source of emissions in the recent past, consistent with pioneer accounts of dense smoke clouds emanating from prairie in the 19th century. Contrary to recent models that suggest increased 20th century combustion emissions could have offset warming effects of rising greenhouse gases, our data suggest that aerosols could have actually decreased over this interval. Although we cannot directly quantify aerosols from our methods, the emissions of large particles suggest assumptions of 20th century aerosol declines should be reconsidered.     

An attempt at the historical reconstruction of the genetic demographic structure of the Moscow population at the turn of the 20th century]

The genetic demographic structure of the Moscow population at the turn of the 20th century was studied based on the data from parish books and census records. The main sources of population gene pool replenishment were analyzed, and migration coefficients and the main parameters of the model of isolation by distance were estimated. Data on so-called quasigenetic markers (ethnicity and birthplace) were used to reveal intrapopulation heterogeneity, which facilitates the adaptation of migrants to a new ethnic and cultural environment. The spatial subdivision was analyzed with the use of GST statistics. Muscovites exhibited a considerable positive assortative mating with respect to birthplace. The results of this study provide the necessary historical perspective for predicting the current genetic demographic trends in the Moscow population. It was shown that the co-efficients of marriage migration were almost the same (0.7 < m < 0.8) in the late 19th and mid-20th centuries; however, these values were two times greater than in the late 20th century. This decrease in marriage migration was accompanied by a threefold increase in the radius of centripetal migration and a threefold decrease in the level of isolation by distance. It was determined that the increase in the ethnic and genetic diversity of the Moscow population in the 20th century had started in the 1860s.     

The main trends in the palaeodemography of the 7th-18th century population of Latvia

The study represents palaeodemographic research of osteological material of 3304 individuals from the funds of the Anthropological Laboratory of the Institute of History of the University of Latvia in Riga, dating from the 7th to the 18th century AD. Compensated life expectancy at birth is varying between 20.3 and 22.2 years during the research period. Crude mortality has changed between 49.3 and 45% per hundred. In the early period (7th-13th century) there is a significant male prevalence (2.2-1.4); female life expectancy at the age of 20 is on average 6.6 years less than for males. This difference decreases to 5.4 years in the 13th-18th century. According to historical demography, female life span exceeded male only in the 2nd half of 19th century. The palaeodemographic data indicate that in the 7th-18th century, women in Latvia gave birth to a mean of 4-5 children (the figure includes childless women), of whom half, at most 2-2.5, reached reproductive age, on account of high child mortality. The net reproductive rate R0 (the number of descendants per individual of the parents' generation) varies between 1 and 1.25 in the study period. Concerning the completely excavated cemeteries of Lejasbiteni (7th-10h century) and Daudziesi (16th-17th century), it was possible to calculate the size and structure of the populations that had used these cemeteries. They were similar, having 45.3-49.9% of children up to an age of 14 and 24-28% individuals over the age of 30. According to historical demography, radical improvement of the demographic situation in Latvia began in the second half of the 19th century, when the process of demographic transition in Latvia started.     

Theory and practice: the impact of Mendelism on agriculture

The purpose of this paper is a reexamination of the success story of how Mendelian genetics gave birth to a revolution in plant and animal breeding which produced the spectacular 20th century agricultural progress and made it possible to feed the exploding population of the Earth. Critics have pointed to the problematic social effect of the agricultural revolution, and they have doubted the importance of the new genetics, especially during the first three or four decades of the 20th century. This paper argues that the criticism has tended to take a narrow instrumental view of science underestimating the guiding role of theory in practical matters. Plant and animal breeding continued to depend mainly on the old 19th century techniques, hybridization, mass selection and individual selection. But they were combined and used in much more efficient ways than before. New theoretical knowledge, general theories as well as particular knowledge about species, strains and individuals, radically improved the planning and execution of breeding work.     

Past, current, and future of the central European corridor for aquatic invasions in Belarus

We analyzed the role of the waterways of Belarus in the spread of aquatic exotic invertebrates through the central European invasion corridor. Present day Belarus became critically important when in the end of the 18th—beginning of the 19th century three interbasin canals connecting rivers from the Black and Baltic seas basins were constructed for international trade. These canals became important pathways facilitating the spread of aquatic alien species. For more than a hundred years, only Ponto-Caspian species colonized Belarus using ships and especially timber in rafts exported by Russia into Western Europe. In the second half of the 20th century, new vectors of spread appeared in Belarus, such as stocking of economically important invertebrates and accidental introductions. This paper is the first comprehensive review of aquatic exotic invertebrates in Belarus. Currently, 19 exotic aquatic invertebrates are known in Belarus, including 14 species of Ponto-Caspian origin. The rate of spread of aquatic invasive species in the second half of the 20th century increased 7-fold compared to the 19th—beginning of the 20th century. We found a significant positive correlation between the time since initial invasion and number of waterbodies colonized. We predict a further increase in the rate of colonization of Belarus by exotic invertebrates as well as an increase in the diversity of vectors of spread and donor areas of alien species, especially when the ongoing reconstruction of the interbasin canals will be completed and the hydrological connection between Black Sea and Baltic Sea basins will be reestablished after an interruption that has lasted for almost a century.     

Dynamics of the genetic demographic structure of the Kursk province population: migration processes

Marriage records from parish books of the second half of the 19th century and marriage records of 1967-1970 and 1993-1995 obtained from registry offices were used to analyze the dynamics of genetically significant parameters of migration and marriage structure with respect to spouses' birthplaces in populations of different hierarchical levels in the Kursk oblast. It was found that, among the persons contracting marriage (both males and females), the proportions of those who were born in the same population and those who were born in any population of the Kursk oblast decreased by about one third and one fifth, respectively, for the 130-year period. In rural and small urban populations, the coefficients of marriage migration in the 19th century were an order of magnitude lower than in the 20th century. The immigration to urban populations was maximum in the late 1960s (m = 0.745 in small towns and m = 0.680 in Kursk), and that to rural populations, in the 1990s (m = 0.344). In both urban and rural populations, the mean distance between the spouses' birthplaces has increased by several times for the period studied. The endogamy level has decreased approximately twofold: from 0.797 to 0.380 in Kursk, from 0.897 to 0.419 in small towns, and from 0.958 to 0.440 in rural districts. The marriage assortativeness with respect to birthplace was maximum in the late 19th century (K = 0.393-0.491) and minimum in the 1960s (K = 0.155-0.246). The increase in genetic diversity of the urban population of the Kursk oblast due to migration has been slowing down since the late 20th century, whereas the outbreeding level is still increasing in rural populations.     

Man, vegetation and climate during the Holocene in the territory of Sagalassos, Western Taurus Mountains, SW Turkey

Past vegetation change and the influence of climate change and anthropogenic pressure during the Holocene is constructed from a series of palynological records sampled from three locations within the territory of the antique site of Sagalassos. The disappearance of the original deciduous oak woodlands and increases in anthropogenic indicator species around 5300 and 4300 b.c. correspond with an increase in settlements in the region. A period of drought following the deforestation may have hampered the recovery of deciduous oak. The timing of the onset of the Bey?ehir Occupation Phase (BO-Phase) in the territory differs between locations, estimates ranging from ca. 1000–800 b.c. to the start of the Hellenistic period (334 b.c.). The most intense period of arboriculture coincides with the Roman and late-Roman periods. Increases in human pressure on the landscape as reflected in the pollen record correspond with an increased rate of sedimentation and fire activity. The timing of the end of the BO-Phase again differs between locations. Estimates range from the 4th century a.d. to the mid 7th century a.d., when a region-wide shift to dry environmental conditions is observed. Numerical analyses show that post BO-Phase vegetation change is largely driven by climate and displays a succession of dry and wet periods that coincided with well-defined European climate shifts, including the Medieval Climate Anomaly and the Little Ice Age. Current agricultural activities in the region are of a very recent (20th century) origin.