Genetic control of geographic variation for cannibalism in the southwestern corn borer,Diatraea grandiosella

The southwestern corn borer,Diatraea grandiosella Dyar, is a subtropical insect whose range has expanded northward within this century. Geographic variation exists between populations at the extremes of the range for a suite of morphological and behavioral characters, including cannibalism. Laboratory colonies established from a Missouri population (37°N lat.) with a high cannibalism rate and a Mexican population (19° N lat.) with a low cannibalism rate were used to examine the genetic basis of cannibalism by means of a controlled breeding design. When larvae were held in pairs on artificial diet in 30 ml plastic cups at 30° C 16L:8D, the highest incidence of cannibalism in both Missouri and Mexican populations was found in larvae 15 to 18 days-of-age (5th and 6th instars). Under these conditions, cannibalism was expressed in 33% of the pairs formed from Missouri larvae and 11% of the pairs formed from Mexican larvae. First and second generation crosses between Missouri and Mexican populations showed an intermediate level of cannibalism, whereas backcrosses to the parental generations showed a regression to the parental phenotypes. These results indicate that cannibalism is under additive genetic control. Larvae from the Missouri parental population were more likely to consume their victim (i.e., cannibalize) once intraspecific killing had occurred than were larvae from the Mexican parental population or from any of the crosses, and female larvae were cannibals more often than were males. Under the conditions employed, no advantage was detected for cannibalism over instraspecific killing for larval weight gain or growth rate.     

Stature in an early mid-19th century poorhouse population: Highland Park, Rochester, New York

If the early 19th century United States was a developing country, then it may be expected that the lowest economic stratum would show some biological consequences of poverty. This report examines that question by estimating stature on 90 male and 64 female adult skeletons from an unmarked cemetery dating between 1826 and 1863. The Highland Park burial ground was adjacent to institutions which interned unfortunates of Rochester, Monroe County, in western New York. The best estimate of male stature (N = 84) is 172.6 cm. A review of other 18th and 19th century height data shows this value not to be relatively stunted, but rather exactly on the predicted mean of its time. If this was a poor population, stunting was not a consequence of poverty. Females (N = 59) showed a best height estimate of 160.0 cm. Less comparative data are available, but this too seems average for the time. A brief discussion of secular trends, changing income inequity and fluctuating stature from the 18th through 20th centuries puts this finding in context.     

The biological standard of living and mortality in Central Italy at the beginning of the 19th century

The biological standard of living in Central Italy at the beginning of the 19th century is analyzed using newly collected data on the height of recruits in the army of the Papal States. The results reveal a decline in height for the cohorts born under French rule (1796–1815). Although this trend was common to many parts of Europe, the estimated magnitude of the decline suggests a worsening of the biological standard of living of the working classes in the Papal States even relative to that of other countries. Despite the differences in the economic systems within the Papal States, no significant geographical variation in height has been found: even the most dynamic and advanced regions experienced a dramatic height decline. Mortality also increased during the period under consideration.     

Tree-ring growth shows that the significant population decline in Norway began decades before the Black Death

The Black Death (1349–1350 in Norway) is often cited as the cause of a severe population decline and building hiatus in the middle of the 14th century. This paper analyses this hypothesis by matching the Black Death with human and environmental impacts on tree-ring growth. The number of buildings dated by dendrochronology in Norway shows a dramatic decline several decades before the plague. In Norway, the building hiatus, which has parallels in several other places in Europe, dates from the late-13th century almost to the 16th century. The first dated houses built after the plague date from the 15th century and many of the logs have exceptionally wide tree rings compared to timber from other periods. Assuming the rapid growth was because of an open landscape, the trees are likely to have grown on infields of farms abandoned due to the 14th century population decline. Since many of these fast-growing trees germinated in the early-14th century and the number of dated buildings drops dramatically several decades before the plague, the Black Death can hardly be the only reason for the population decline in Norway and one plausible explanation is that some environmental impact occurred decades earlier. The dendroclimatological evidence of cold and wet summers in the years before the plague is suggestive, but historical sources also pinpoint famine due to crop failure. They also tell of farms being abandoned several decades before the plague and mention periods of heavy rainfall and famine in the early-14th century.     

The role of seabirds and seals in the survival of coastal plants: lessons from New Zealand Lepidium (Brassicaceae)

Six of the eight indigenous New Zealand Lepidium species are coastal, and have restricted or reduced distributions. One is extinct and the remainder are considered threatened with extinction. This limited distribution is in marked contrast to their apparent abundance in the eighteenth and early nineteenth centuries (1760s–1830s). Accounts from the voyages of Cook, Surville and d'Urville describe L. oleraceum as an abundant coastal plant which was collected extensively for use as an antiscorbutic. However, by the late 19th century, resident botanists were expressing concern about the marked decline in coastal species of Lepidium, a decline which has continued to the present. Ecologically, coastal species of Lepidium are similar, being restricted to open sites often close to the high tide mark. They are commonly associated with bird colonies, and occasionally with fur seal colonies. Traditionally their decline has been attributed to introduced herbivores. However, wild grazing animals were not common until the end of the 19th century, well after the initial decline had occurred. Other possible reasons for their decline include herbivory and predation by rats, and by fungal and invertebrate pests of cultivated Brassicaceae, overcollecting and coastal development. However, we suggest that a major factor in the decline of coastal Lepidium species was a decline in coastal seabirds through predation and seals through culling. Seabirds and seals are critical for the survival of Lepidium species by keeping sites open through disturbance, dispersing seed, and providing nutrient enrichment for plant growth, and their loss has resulted in decline of habitat for Lepidium.     

America's red gold: multiple lineages of cultivated cochineal in Mexico

Cultivated cochineal (Dactylopius coccus) produces carminic acid, a valuable red dye used to color textiles, cosmetics, and food. Extant native D. coccus is largely restricted to two populations in the Mexican and the Andean highlands, although the insect's ultimate center of domestication remains unclear. Moreover, due to Mexican D. coccus cultivation's near demise during the 19th century, the genetic diversity of current cochineal stock is unknown. Through genomic sequencing, we identified two divergent D. coccus populations in highland Mexico: one unique to Mexico and another that was more closely related to extant Andean cochineal. Relic diversity is preserved in the crops of small‐scale Mexican cochineal farmers. Conversely, larger‐scale commercial producers are cultivating the Andean‐like cochineal, which may reflect clandestine 20th century importation.     

Genetic diversity, population structure, effective population size and demographic history of the Finnish wolf population

The Finnish wolf population (Canis lupus) was sampled during three different periods (1996-1998, 1999-2001 and 2002-2004), and 118 individuals were genotyped with 10 microsatellite markers. Large genetic variation was found in the population despite a recent demographic bottleneck. No spatial population subdivision was found even though a significant negative relationship between genetic relatedness and geographic distance suggested isolation by distance. Very few individuals did not belong to the local wolf population as determined by assignment analyses, suggesting a low level of immigration in the population. We used the temporal approach and several statistical methods to estimate the variance effective size of the population. All methods gave similar estimates of effective population size, approximately 40 wolves. These estimates were slightly larger than the estimated census size of breeding individuals. A Bayesian model based on Markov chain Monte Carlo simulations indicated strong evidence for a long-term population decline. These results suggest that the contemporary wolf population size is roughly 8% of its historical size, and that the population decline dates back to late 19th century or early 20th century. Despite an increase of over 50% in the census size of the population during the whole study period, there was only weak evidence that the effective population size during the last period was higher than during the first. This may be caused by increased inbreeding, diminished dispersal within the population, and decreased immigration to the population during the last study period.     

The status of the Corncrake Crex crex in Britain in 1998

A census of Corncrakes throughout Britain was carried out in 1998. National Grid squares of 10 km in the Hebrides, Northern Isles and the mainland of Highland Scotland known to have held the species during the breeding season since 1988 were searched systematically by night for singing males. A sample of such squares elsewhere in Scotland was also searched. In addition, bird-watchers and the general public were encouraged by press publicity to contribute records of singing birds, which were checked for accuracy. A total of 589 singing males was counted in 93 10-km squares. Ninety percent of the population was in the Hebridean Islands. The total count was 23% larger than in the previous census in 1993 and 3% larger than in 1988. All surveys of distribution and censuses between the late 19th century and 1993 recorded a progressive decline in the national population and range. The average rate of population decline between 1988 and 1993 was 3.5% per year, but between 1993 and 1998 the population increased by an average of 4.2% per year. However, annual counts from 1993 to 1998 in core areas that held more than 90% of the population, showed that this overall increase resulted from four successive annual increases of 4–16% followed by a decline of 15% between 1997 and 1998. There was considerable variation among islands and areas in the rate of change of their Corncrake numbers.     

Low twinning rate and seasonal effects on twinning in a fertile population,the Hutterites

This paper analyzes from the mid 18th century to 1987 the birth records of the Dariusleut, one of the three subgroups of the Hutterite population. The aim of this study is to describe several aspects of the twinning rate in a fertile population. The overall rate of twinning was 0.90%:103 twins among all 11492 maternities. The rate peaked at the 7th birth order and at the maternal age of 40 years and over. Until the mid 19th century when the Hutterites lived in Russia, the twinning rate was higher (1.5%), and it decreased during the migration period in the second half of the 19th century (0.7%). After the group had settled in the USA and Canada, the population maintained a twinning rate of 1.0% until 1965. After 1965 the rate decreased to 0.7%, partly due to a decline in fertility among women aged 30 years and over. There was a significant seasonal variation: the twinning rate decreased to 0.5% in May–July compared to 1.2% for the other three seasons during the years up to 1965 (P<0.01), while more recent mothers did not show such a seasonal variation. The incidence of twin births in this population seems to have been influenced by environmental factors, which would change their effect seasonally and secularly.     

Secular trends of twinning rate in Sweden.

The change in parity and maternal age in Sweden accounts for the decline in the twinning rate from the 19th century to the middle of the 20th century. The later decline in twinning rate cannot be explained by changes in maternal age and parity. Fecundity appears to be higher in mothers of twins than in other mothers.     

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.     

Inferring species decline from collection records: roller dung beetles in Italy (Coleoptera, Scarabaeidae)

The decline of roller dung beetles (Coleoptera, Scarabaeidae) in Italy, at national and regional level, was described using a database of both literature and unpublished data, since the late of 19th century. The probability of finding roller species was assessed for each decade of the 20th century in order to detect changes in their distribution and status. An analysis of decline was performed using a complementary approach of different extinction indexes, according to IUCN criteria. During the 20th century, both the absolute number of records and the UTM cells where roller beetles were found increased clearly as a consequence of the escalation of entomological surveys. Nevertheless, comparing R species (rollers) with all the scarab dung beetles from the first to the last quarter of the 20th century, the relative frequency of roller records decreased by 31%, while the relative number of occupied UTM cells dropped by 23%. Six roller species showed a significant decline in Italy from the first to the second part of the 20th century, and nine in the last 30years. Other two species disappeared from the majority of the northern regions. Finally, the values of all the extinction indexes were strongly correlated and detected a high risk of extinction in Italy for six species. A gradual change in land use during the last three decades, consisting of a reduced extension of grasslands in favour of either intensive agriculture or reforestation after abandonment of livestock raising, was likely the main factor inducing decline and local extinction of roller species.     

Racial differences in body mass indices of men imprisoned in 19th Century Texas

A limited amount of research has been done on the body mass index values of 19th century Americans. This paper uses Texas prison records to demonstrate that, in contrast to today's distributions, most BMI values were in the normal range. Only 21.5% and 1.2% of the population was overweight or obese, while today comparable figures are 36% and 23%. There was also little change in BMI values between 1876 and 1919. Farmers were consistently heavier than non-farmers, while Southwestern men had lower BMI values than their counterparts from other regions of the US. BMI values indicate that 19th century African-Americans, and whites populations were well fed in spite of large expenditures on energy.     

Ancient-to-modern secular changes in Korean stature

Statural growth in human populations is a sensitive indicator of socio-economic well-being, and improvements in socio-economic status are reflected in secular increases in adult height. In the present study, we investigated the statures of historical Korean societies to show how stature changed over time. Applying Fujii's equation, derived from modern Japanese, to the measurement of femora removed from 15th- to 19th-century Joseon tombs, the average heights of Korean adults during the Joseon dynasty were estimated to be 161.1 ± 5.6 cm and 148.9 ± 4.6 cm for males and females, respectively. Plotting statures for successive historical societies against time revealed that Korean heights remained relatively unchanged through to the end of the 19th century, a pattern that differs from that seen in many Western countries in which stature transiently decreases after the Middle Ages. In contrast, a sharp increase in Korean stature was observed at the beginning of the 20th century, similar to trends seen in other nations (although exact timing varies in different countries). There were no accompanying changes of stature sexual dimorphism. The data reported in this study reflect the unique historical experience of Korea; the relative isolation of Joseon society, the late onset of modernization (at the end of the 19th century), and the later occurrence of industrialization (during the 1960s).     

Influences of infrequent fire, elevation and pre-fire vegetation on the persistence of quaking aspen (Populus tremuloides Michx.) in the Flat Tops area, Colorado, USA

Aim  The recent concern that quaking aspen ( Populus tremuloides Michx.) has been declining in parts of western North America due to fire suppression is largely based on trends during the latter part of the 20th century. The aim of the current study was to compare the extent of aspen in the modern landscape with its extent in the late 19th century prior to fire suppression, and to assess the effects of elevation, late-19th century fires, and pre-fire forest composition on the successional status of aspen.
Location  North-west Colorado, USA.
Methods  We used a georeferenced 1898 map and modern maps to examine trends in aspen dominance since the late 19th century in a 348,586 ha area of White River and Routt National Forests in north-western Colorado. Stand age and structure were sampled in 30 stands.
Results  We found no evidence of overall aspen decline over this period. In fact, aspen distribution has increased in parts of the study area following severe fires in the late 19th century in forests that were previously dominated by conifers. Aspen persistence and increase was especially pronounced at elevations below 3000 m a.s.l. Most 120-year-old post-fire stands that are presently being successionally replaced by conifers were dominated by conifers prior to the last severe fire.
Main conclusions  Human perceptions of ecosystems are often on time scales that are shorter than the cycles of natural variation within those ecosystems. This disparity may lead to an underestimation of the range of natural variability of ecosystem patterns and processes. The appropriate temporal scale of inquiry is necessary for the correct understanding of natural variation in ecosystems.     

History of anthropology

The author describes the history of biological anthropology with special reference to the period from 17th to 19th century. The most important anthropological theories and methodological developments of that time as well as their representatives are discussed in detail.     

Physical stature of men in eighteenth century Mexico: Evidence from Puebla

We present a first glimpse of the mean height of men in eighteenth century Mexico based on evidence from the Revillagigedo Census of 1791–1792. Mexican men were shorter than those of Europe and North America. For example, contemporary French men were about 165 cm and US men were about 174 cm; in contrast, Mexican men were about 162 cm. Men of higher income were taller than those in the middle and lower income strata. Mestizos (a mix of whites and Indians) were shorter than the rest of the recruits belonging to other ethnic categories.     

Conservation implications of a long-term decline in body condition of the Brothers Island tuatara (Sphenodon guntheri)

Understanding the factors that drive the dynamics of remnant populations of long-lived species presents a unique challenge for conservation management. The long-lived Brothers Island tuatara Sphenodon guntheri is represented by one natural, self-sustaining population on 4-ha North Brother Island, New Zealand, and two small, translocated populations. The North Brother Island population was almost driven to extinction by extreme habitat modification and collecting in the late 19th century. Analysis of a long-term (1957–2001) dataset, following the population's recovery, reveals a significant decline in tuatara body condition over time, which is more pronounced in females. Declining body condition, coupled with very low reproductive output, may be symptomatic of a density-dependent response to elevated population size exacerbated by resource limitation. Sex-specific effects that disadvantage females could compromise this small population, particularly as it exhibits a male-biased sex ratio. We recommend removal of infrequently used structures and habitat restoration to alleviate intense resource competition. Population-level manipulation should be considered if future monitoring indicates an increasingly male-biased sex ratio and continued decline of female body condition.     

贵州雷公山秃杉种群生活史特征与空间分布格局

秃杉是一种珍稀濒危植物,以斑块状分布于雷公山东南面斜坡海拔800-1300 m之间的沟谷两侧。从年龄结构、生命表特征、存活曲线以及种群不同龄级个体空间分布格局等方面研究了雷公山秃杉种群生活史特征与空间分布格局。研究结果表明:秃杉的种群结构存在波动性,成年阶段个体较丰富,幼苗与老龄数目相对较少,秃杉自身的生物学特性及环境因素是形成这种现象的主要原因;秃杉种群存活曲线趋于DeeveyⅡ型,出现2个死亡率高峰,一个出现在第6龄级阶段,另一个出现在第12龄级阶段,期望寿命单调下降;秃杉种群空间分布格局总体上为聚集分布,处于不同发育阶段的秃杉种群,其分布格局随时间而发生变化,从幼龄期到中龄期再到老龄期,种群分布格局由聚集分布逐渐变为随机分布,秃杉种群在不同发育阶段的空间分布格局差异与其生物学和生态学特性密切相关,同时受群落小环境的影响。