Skin colorimetry in Belize. II. Inter- and intra-population variation

Skin colorimetry readings taken in Belize, Central America (formerly British Honduras) with the two most commonly used portable reflectometers reveal significant differences in mean reflectance between Garifuna (Black Caribs) and Creoles, and between Garifuna in two settlements. These differences are related to variation in African, Indian, and European admixture, as estimated from serological markers. Sex differences are not evident in univariate comparisons, but females are significantly lighter than males in multivariate analyses of variance. Polynomial age trends exist in some groups for certain variables, but account for a very small amount of the variation in skin color within these groups.     

Analysis of HLA-DRB1 polymorphism in the Gidra of Papua New Guinea

The genetic structure of the Gidra-speaking population inhabiting 13 villages in Papua New Guinea was investigated, based on the analysis of HLA-DRB1 polymorphism. Nei's fixation indices (F(IS), F(IT), and F(ST)) showed that the Gidra villages were genetically differentiated. The genetic distances significantly correlated with the geographic distances among the 13 villages. Thus, it is likely that a low intervillage migration rate has been maintained since the Gidra community was established. Correspondence analysis revealed that the Gidra, who belong to non-Austronesian-speaking groups, are genetically located at the intermediate point between the Aboriginal Australian groups and the Austronesian-speaking groups. Moreover, the HLA-DRB1*0802 allele, which has been observed in only two Polynesian groups (Austronesian-speaking groups) of Oceanian populations, was also found in the Gidra. These results suggest that the admixture of Austronesian and indigenous non-Austronesian groups beyond the linguistic boundary occurred partly in Papua New Guinea before Austronesian groups spread to the Pacific.     

Inter- and intra-population differences in the effects of temperature on postdiapause development of Delia radicum

Canadian populations of D. radicum differ in their response to temperature during postdiapause development. Populations that are primarily of the early-emerging type ( ) (St-Jean, Quebec; London, Ontario) have high values for the parameters describing this response: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOuamaaBa% aaleaacaWGTbaabeaakiabg2da9aaa!38F2!$$R_m = $$ 12.7–13.3; 28.0–31.8 °C ; T = 10.3–14.2 ( , the maximum developmental rate at the temperature, [ °C ] where the developmental rate is highest, and T , the parameter which gives the shape of the truncated normal curve fitted to the data), a low degree-day requirement for emergence (160–232 ), and may lack a developmental delay at temperatures above ca. 21 °C . Populations of the late-emerging type (Kildare, Prince Edward Island) have low parameter values ( , °C ; T = 6.4), high degree-day requirements (530 ), and a developmental delay at high temperatures. The parameters for the early-emergers in the population from Winnipeg, Manitoba (74% early) were intermediate ( , °C , T = 10.7, ), but resembled the early rather than the late type. This population varied from 31 to 90% early type over a 10-year period and the rate of postdiapause development at 20 °C was directly related to the percentage early. In the year with the most rapid development (90% early), development was significantly slower than in the populations from other locations with predominantly early populations, and the year with the slowest development (31% early) showed significantly faster development than that from Kildare, Prince Edward Island (100% late). Therefore the parameters for early and late types of development will not be accurate for use in mixed populations, and the parameters in mixed populations will change among years. Populations of D. radicum in North America and Europe (67 locations by years) varied from 0–100% early. At Winnipeg, the percentage early was directly related to the annual temperature accumulation ( ) during the growing season. The calculation of developmental parameters for the early-emergers of mixed populations provides a more accurate basis for estimating the times of first emergence and the first peak of emergence than parameters based on the whole population. Since postdiapause developmental rates vary both among and annually within locations, developmental models should be designed to include such variations.     

Inter- and intra-population genetic divergence of East Asian cattle populations: focusing on Korean cattle

In order to facilitate the on-going cattle conservation and improvement programs in Korea, we examined genetic relationships among East Asian cattle, focusing on Korean native cattle, using complete mitochondrial DNA control region sequences. In total, 67 haplotypes were discriminated by 97 variable sites in East Asian cattle. Of the variable sites, 35 represented singleton variable sites and 62 were parsimony informative sites. For Korean cattle, 30 haplotypes were discriminated by 40 variable sites. The variable sites identified in this study correspond to transition or transversion point mutations. Inter-populations genetic distance varied from 0.004 to 0.052 for East Asian cattle populations. The genetic divergence observed between Korean Brown and Jeju Black (0.004) was among the lowest. The Mongolian cattle were slightly divergent from other East Asian cattle populations studied. The network analysis uncovered that Jeju Black and Yunbian samples represented the possible ancestral Haplotype within T3 Bos taurus main lineage. Thus, we hypothesized that the Jeju and Yunbian cattle may represent one of the original native North East Asian cattle in the region.     

Low rate of population increase of the Gidra Papuans in the past: a genealogical-demographic analysis

The population increase rate of the Gidra in lowland Papua in the past was estimated using the rate of intergenerational replacement of females based on genealogical records involving 889 women, alive or deceased, who completed reproduction. During the period from a century ago to the time of manifest influence of civilization several decades ago, the Gidra had a constant annual increase rate of about 0.2%. The discussion includes a historical assessment of this rate with reference to the local conditions and an ecological explanation for its microenvironmental variation and suggests a reassessment of the methodology for studying fertility and population growth in anthropological and prehistoric populations.     

Inter- and intra-population variations in diapause attribute of the two-spotted spider mite,Tetranychus urticae Koch,in Japan

Populations of the two-spotted spider mite, Tetranychus urticae Koch collected from various localities and from various host plants in Japan showed wide variations in diapause attribute. Diapause percentages at 18°C/9L15D varied from nearly 100% in the north to 0% in the south-west. At intermediate latitudes the mites showed wide inter-population variations. Populations on herbaceous hosts in vinyl- or glass-houses gave significantly lower incidence of diapause than those on roses and deciduous fruit trees. Presence of winter hosts and better host quality under protected environments seemed to favour non-diapausing mites. The temperature threshold for diapause expression also varied widely among local populations. Northern populations consistently had higher and less variable thresholds than populations at intermediate latitudes with thresholds between 15 and 18°C. Inbred lines derived from a population in Kyoto exhibited a wide variation in diapause percentage at 18°C. These results show that diapause in T. urticae is a quantitative threshold trait and that populations in central Japan consist of a variety of genotypes with different diapause traits. This might provide a genetic source for adaptation to local and temporal variations in environmental conditions.     

Sodium-rich tree ash as a native salt source in lowland Papua

The Gidra-speaking Papuans of the Oriomo Plateau, lowland Papua New Guinea, consume ash of two tree species (Melaleuca sp. andAcacia mangium) as a native salt. The ashes contain 100–200 mg sodium/g ash, which is very much higher than the sodium levels in native plant ashes (except for the swamp herbEriocaulon australe) collected in other regions of the world.     

Yams and megapode mounds in the lowland rain forest of Papua New Guinea

Kubo people of Papua New Guinea sometimes grew Dioscorea yams in mounds of forest litter that were made as egg-incubation sites by birds (Megapodiidae).' The small yam plots were included within larger banana gardens and, in the latter, it was yams, not bananas, that took precedence in the gardening decisions of people. The technique would be viable in the absence of a larger garden. It is interpreted as an expression of an ancient pattern of small-scale plant domestication.     

Annual movement and migration of adult pikeperch in a lowland river

The downstream migration of 46–66 cm radio-tagged adult pikeperch Stizostedion lucioperca , in the River Gudenaa, Denmark, from late September to late December, coincided with a reduction in the frequent occurrence of prey fish in the tagging area, and hence was interpreted as a feeding migration. The upstream migration from March to mid-April in spring took place prior to spawning which occurred from late April to June.     

Forest carbon in lowland Papua New Guinea: Local variation and the importance of small trees

Efforts to incentivize the reduction of carbon emissions from deforestation and forest degradation require accurate carbon accounting. The extensive tropical forest of Papua New Guinea (PNG) is a target for such efforts and yet local carbon estimates are few. Previous estimates, based on models of neotropical vegetation applied to PNG forest plots, did not consider such factors as the unique species composition of New Guinea vegetation, local variation in forest biomass, or the contribution of small trees. We analysed all trees >1 cm in diameter at breast height (DBH) in Melanesia's largest forest plot (Wanang) to assess local spatial variation and the role of small trees in carbon storage. Above‐ground living biomass (AGLB) of trees averaged 210.72 Mg ha^?1 at Wanang. Carbon storage at Wanang was somewhat lower than in other lowland tropical forests, whereas local variation among 1‐ha subplots and the contribution of small trees to total AGLB were substantially higher. We speculate that these differences may be attributed to the dynamics of Wanang forest where erosion of a recently uplifted and unstable terrain appears to be a major source of natural disturbance. These findings emphasize the need for locally calibrated forest carbon estimates if accurate landscape level valuation and monetization of carbon is to be achieved. Such estimates aim to situate PNG forests in the global carbon context and provide baseline information needed to improve the accuracy of PNG carbon monitoring schemes.     

Swidden cultivation in forest and savanna in lowland southwest Papua New Guinea

Ecological aspects of traditional swidden cultivation by Bine- speaking groups in wetland areas of lowland southwest Papua New Guinea are examined. A notable feature of the area is the coexistence of extensive, polycultural forest cultivation and more intensive, specialized savanna cultivation. Both agrosystems occur on soils of inherently similar properties. The savanna vegetation is secondary in character and, once established, is better suited to more intensive swidden cultivation based on taro (Colocasia esculenta). The agrosystems in question represent stages in the local development of agriculture, and, although multiple causes of intensification may be involved, the study confirms that lowland, as well as highland, areas of New Guinea have provided development opportunities for traditional cultivators.     

Predation on artificial and natural nests in the lowland rainforest of Papua New Guinea

Capsule: Although survival of nests was similar between forest fragments and continuous forest, the range of predators differed. Artificial nests provide an under-estimate of nest predation by snakes.

Aims: To estimate the natural nest predation rate in continuous primary forest, compare it with predation rates in forest fragments. To assess the reliability of nest survival rates determined by the use of artificial nests with clay eggs and identify the main nest predators.

Methods: We observed survival of natural nests during the incubation period in continuous primary forest in Papua New Guinea. Some nests were monitored with infrared cameras. We also used artificial nests deployed with clay eggs to identify predators.

Results: There was a predation rate of 50% for natural nests and snakes were major predators of nest contents. Clutch daily survival rates (DSRs) differed among nest types. The DSR of artificial nests (0.977) was not significantly different to that of natural cup nests (0.969). Survival rates of artificial nests were similar in forest fragments and continuous forest. Forest fragments had, however, a higher proportion of avian predators than continuous forest.

Conclusion: Although, we observed similar survival rates in artificial and natural nests, the composition of nest predators was different between natural and artificial nests. Artificial nests were not suitable for estimating the real predation caused by reptiles. Nevertheless, we find that participation of avian nest predators can be estimated correctly with the use of artificial nests.     

Body mass in lowland gorillas: a quantitative analysis

Body proportions and tissue composition (e.g., relative contributions of muscle, skin, bone, and adipose to total body mass) were determined through dissection of four adult captive lowland gorillas. The relative contribution of bone varies little among the four animals (10.2-13.4%) despite considerable range in body weights (99.5-211 kg). In tissue composition, three animals have on average 37.3% muscle relative to body mass. Maximum estimates of body fat range between 19.4-44%. Differences in age, sex, and life history events partially explain the observed variation in body proportions and tissue composition among the four animals. Although gorillas are considered extremely sexually dimorphic in body weight and canine size, differences in tissue are not as dramatic as body mass differences suggest. This study found sex differences mostly in the upper body; males have relatively heavier forelimbs, including heavier deltoid, trunk-binding, and deep back muscles compared to the younger female. The old, obese female had one half the muscle tissue of the other three animals (16% vs. 37.3%), and twice the body fat (44%); forelimbs and upper body musculature were relatively well-developed to compensate for the restricted hip-joint movement due to arthritis. Data on the variation in tissue composition and body proportions in gorillas provide a basis for comparison with other hominoids, including humans. For example, compared to highly dimorphic orangutans, gorillas have more muscle, less adipose tissue, lighter forelimbs and heavier hindlimbs. Such analyses complement studies of the skeleton and contribute to our understanding of human evolution and adaptation.     

A Holocene record of savanna vegetation dynamics in southern lowland Papua New Guinea

Vegetation History and Archaeobotany - The southern lowlands of Papua New Guinea (PNG) are biogeographically distinct. Vast tracts of savanna vegetation occur there and yet most palaeoecological...     

Inter and intra-population variability of Pongamia pinnata: a bioenergy legume tree

Pongamia pinnata is an oil-producing tree species with multiple uses and considerable potential as a bioenergy crop. This investigation was carried out to assess the extent of genetic structure in a representative set of 226 individuals of Pongamia pinnata encompassing seven populations as a prelude to utilization of promising and genetically divergent material in breeding programmes. Molecular polymorphism was 67.18% with ten inter simple sequence repeats (ISSR) between the individuals indicating modest levels of genetic variation in the Pongamia pinnata germplasm collected. The within-population variation based on ISSR polymorphism was 32.34% and polymorphism at the species level was 94.3%. Genetic differentiation between populations (GST = 0.61) was positively correlated with geographical distance. The data obtained indicate an immediate need to widen the genetic base of Pongamia pinnata germplasm for proper characterization, and for extensive plantations of elite varieties to meet the demands for biodiesel.     

Male social status and its predictors among Garisakang forager-horticulturalists of lowland Papua New Guinea

Social hierarchy exists in all human societies, yet the characteristics important for achieving high social status may differ cross-culturally. Studies among Western industrialized populations often use indices of socioeconomic status (SES) to determine individual social position. Conversely, studies among small-scale societies typically use locally relevant traits. Cross-cultural applicability and the relationships between these two strategies have rarely been investigated. Studies limited to industrialized societies demonstrate that low social status is associated with poor health and elevated levels of chronic stress. It remains unclear, however, if and to what extent this relationship is a recent phenomenon in industrialized Western society or a universal human characteristic that has likely been present throughout much of our recent evolutionary history. In this study, we investigate relationships between various SES and locally relevant measures of male social status, age, body-mass index (BMI), and levels of waking salivary cortisol among relatively egalitarian Garisakang forager-horticulturalists of lowland Papua New Guinea. We employ a photo-ranking method using 32 raters (16 women, 16 men) to evaluate 15 measures of social hierarchy in men (N = 32). These measures target locally relevant traits considered important for male social status (e.g., sociability, hunting skills, fighting ability, and community influence). Using principal component analysis (PCA), we extracted two components labeled as Dominance-Respect and Prosociality-Skills. Models investigating predictors of social status demonstrate that age was significantly and positively related to both Dominance-Respect and Prosociality-Skills while BMI was positively related to only Dominance-Respect. Neither Dominance-Respect nor Prosociality-Skills predicted salivary cortisol levels. However, the SES measure of Income was significantly and positively related to cortisol levels, suggesting that men with higher income experience higher levels of stress. This finding may be explained by increased psychological stress accompanying market integration among the Garisakang or, alternatively, by culturally specific expectations for resource sharing and fear of conflict. These findings emphasize the usefulness of diverse social status measures in anthropological research and stress the need for broadened perspectives regarding the causes and consequences of social status among small-scale populations.     

The vertical distribution of flying insects in lowland rain-forests of Panama, Papua New Guinea and Brunei

Ultra-violet light traps were hung at four vertical levels, to monitor the distribution of flying insects in the rain-forests in Panama, Papua New Guinea (PNG) and two sites in Brunei. Large insects were excluded. Ninety-eight thousand, five hundred and sixty-nine insects were trapped and the entire catch was analysed to order and in some cases to lower taxa. Clear vertical stratification was shown by most taxa and, in some cases, there was a marked concentration of numbers in the upper canopy at all four sites. In others there was no such concentration and considerable differences in vertical distribution were seen between the sites. These differences are discussed in relation to the forest structure at each site and in relation to the results obtained in Zaire. We conclude that flying insects in tropical rain-forests are not always concentrated in the upper canopy, although there is a tendency for this to occur where topography and forest structure are simple.     

Horizontal migration of zooplankton in a littoral zone of the lowland Sulejow Reservoir (Central Poland)

Horizontal migrations of zooplankton between macrophyte patches and open areas were investigated in the sparsely vegetated littoral zone of the Sulejow Reservoir in June-July 2000 and 2001, using one-litre plastic traps. Large-bodied zooplankton: daphnids and copepods generally swam towards the open water at dusk and towards submerged macrophytes at dawn. Small-bodied zooplankton (Bosmina sp., Chydorus sp.) did not show any pattern of horizontal movement. At the time of the research the phytoplankton community was dominated by eatable diatoms (Cyclotella sp.), whose biomass reached 14 mg l⁻¹. Thus, bottom-up forces (food scarcity) are not likely to be responsible for the observed zooplankton migrations. Analyses of fish stomach contents showed high contribution of large zooplankters to the food of juvenile roach (Rutilus rutilus) and perch (Perca fluviatilis) which densely inhabited the littoral zone of reservoir. High fish pressure in the littoral zone along with high density of the predatory cladoceran, Leptodora kindtii in the open water, suggest that top-down forces (predatory pressure) were responsible for the migration of large zooplankton. At dusk predatory pressure of fish fry exceeded that of L. kindtii, forcing endangered zooplankton to escape from macrophytes towards open water. The opposite situation occurred at dawn. The consequences of the relationships for both zooplankton and fish fry communities dynamics are discussed.