Genetic studies in Ecuador: Acetylator phenotypes,red cell enzyme and serum protein polymorphisms of Shuara Indians

Population genetic studies of Shuara Indians in Ecuador are performed for GPT, AP, PGM₁, Ak, EsD, 6-PGD, Hp, Gc, C3, Bg, ChE, Tf, Pi, Bf phenotypes, IgG, IgA, IgM, C3, C3-proactivator, C4 levels and acetylator phenotypes. Some systems having a polymorphism in many other populations showed a lack of some of those alleles in the population under study (C3, ChE, Tf, AK and almost absent 6-PGD, Bg, Bf).     

Some observations about racial boundaries and the experiences of American Indians

The number of inter‐racial marriages has increased sharply in the last two decades. There are a number of factors that might account for this development ‐ for example, immigration, changing norms, and marriage market composition ‐ but one indisputable outcome has been a rise in the number of persons with multiracial backgrounds. This article argues that multiracial persons have a number of options about how they might identify their ancestry, and this is causing fluidity and instability in racial divisions that were once considered fixed and immutable. While this might be seen as a recent development, American Indians historically have had high rates of intermarriage with other racial groups. The experience of American Indians with regard to the dilemmas posed by shifting racial identities are discussed for the purpose of anticipating the experiences of other groups. In particular, these issues pose a number of challenges to public policies based on increasingly obsolete conceptions of race.     

Diabetes mellitus in the Pima Indians: genetic and evolutionary considerations

Non-insulin-dependent diabetes mellitus is a common disease in the Pima Indians. It is familial and strongly related to obesity. Neel (1962) suggested that the introduction of a steady food supply to people who have evolved a "thrifty genotype" leads to obesity, insulin resistance, and diabetes. Our findings in the Pimas of differences in insulin sensitivity in different metabolic pathways suggest that the thrifty genotype involves the ability of insulin to maintain fat stores despite resistance to glucose disposal. The recent increase in diabetes incidence following the availability of an abundant food supply suggests that the ability to store energy efficiently during cycles of feast and famine may now lead to obesity, insulin resistance, and diabetes.     

Avian rarity in ten cloud-forest communities in the Andes of Ecuador: implications for conservation

Avian rarity was investigated in ten high-altitude cloud forests in the Andes of Ecuador. Data on species compositions and abundances were obtained by a fully standardized method (standardization for area, altitude, habitat, effort and seasonality). The rare species were isolated from rank-abundance plots on the basis of the quartile definition of rarity. A positive correlation between mean abundances of species and number of sites occupied suggests that high-altitude bird species classified rare by abundance generally can also be classified rare by range. However, it is necessary to be cautious using this result in ranking conservation priorities since the generality is not obeyed by all species. Within the two abundance classes (contains one and two individuals, respectively) represented among the rare species, the one-individual class had significantly more species than the two-individual class. The quantitative rarity of taxa and ecological groupings produced similar results for all sites, while pairwise similarity of rare species between sites was very low. Together with the difficulty of identifying species that are truly rare by abundance, these results imply that sites selected for conservation preferably should be based upon a qualitative evaluation of lists of species referred to vulnerability categories such as endemic, restricted-range, CITES or IUCN threatened/near-threatened species. However, it is necessary also to incorporate other aspects of biodiversity to cover a full range of biotic diversity.     

Formation of the permanent dentition in Arikara Indians: timing differences that affect dental age assessments

This report concerns one problem encountered with application of American white dental formation standards to age assessment of sub-adults of archaeological context. Dental ages for eight mandibular permanent teeth and maxillary central and lateral incisors of Arikara Indian immature skeletons were determined according to degree of crown or root mineralization. Ages assigned to the various teeth of the same individual were compared. They showed similarities as well as patterned differences. First premolar, second premolar, and mandibular incisor ages closely approximated one another. In relation to this complex, dental ages for maxillary incisors and mandibular second molars were older by 0.5 to 1.1 years. Developmental ages assigned to individuals on the basis of third molars showed relative advancement by more than 2 years. The systematic occurrence of these observations reflects more than just individual variability; it shows the presence of population differences in tooth-formation timing. Timing differences complicate assessment of dental ages needed for growth or demographic studies.     

Patterns of dental wear in the Lengua Indians of Paraguay

Wear patterns were examined on dental casts of 202 living Lengua Indians from the Chaco area of Paraguay. Consideration was given to the development of the molar helicoidal plane, age-related changes in occlusal attrition, coalescence of dentine exposures, interproximal attrition, and erupted crown height. This study lends support to Osborn's theory of the helicoidal plane development by showing that attrition enhances rather than modifies posteruption molar occlusal planes. The rate of interproximal attrition was found to slow down with the eruption and functional initiation of the third molars. Sinuous and cavo-convex interproximal contact areas that are generated with age, however, appeared to be less abrasion resistant than straight surfaces, hence leading to an increase in interproximal attrition rates with advanced age. Maximum crown height reduction occurred between the ages of 20 and 40 years in central incisors, canines, and first molars. Kruskal-Wallis tests and log linera models failed to demonstrate significant sexually dimorphic or antimeric differences in wear patterns of Lengua teeth.     

Racism and the politics of signification: Israeli public discourse on racism towards Palestinian citizens

This paper explores the phenomenology of racism using the Israeli situation as a case study to examine if, when and how the concept of ‘racism’ is employed in local media discourse on policy towards Palestinian citizens.

Our central argument is that racism, as a signifier of policy, can be located in the dialectic between denial and affirmation of the category of race, while we link the scope and meanings of practices marked by the media as ‘racism’ to contingent cultural, social and historical conditions. The article proposes the periodization of the relevant discourse into three primary phases: from 1949 to the late 1970s, when the category of racism was ‘prohibited’ in Israeli discourse in the aftermath of the Holocaust; the mid-1980s, when this taboo was broken and the phenomena included in the category of racism expanded accordingly; and the 1990s to 2000, during which racism became an institutionalized, all-encompassing discursive term.     

Physical growth and development, neurological maturation and behavioral functioning in two Ecuadorian Andean communities in which goiter is endemic. I. Outline of the problem of endemic goiter and cretinism. Physical growth and neurological maturation in the adult population of La Esperanza

Animal experiments indicate that chronic dietary iodine deficiency can have a marked effect on neurological maturation and the consequent behavioral capacities of the individuals so affected. Goiter, enlargement of the thyroid gland, is hyperendemic throughout the Andean region of Ecuador and is associated with an insufficient dietary intake of iodine. In these populations there is also a strikingly high prevalence of gross mental and physical developmental retardation that has been classified under the rubric of “endemic cretinism.” Anthropometric measurements and Bender Gestalt productions were collected from 44 deaf-mute “cretin” and 344 “normal” adult individuals in the parroquia of La Esperanza. The anthropometric data were generally comparable to that of other Ecuadorian Andean populations which have been studied. The deaf-mute “cretin” group showed retardation in physical growth and marked retardation in visual motor maturation compared to the “normal” population. Seventeen percent of the “normal” population showed clear signs of neurological deficit in visual motor perception. The data suggest that in addition to the large number of grossly retarded “cretins” in these populations, many of the “normal” individuals show some degree of neurological deficit, thus forming a continuum from frankly retarded, through moderately and slightly affected, to normal individuals. The socio-cultural adaptations to the presence of a large number of retarded individuals in the community are discussed.     

Changes in osteoarthritis associated with the development of a maritime economy among southern California Indians

The severity of osteoarthritis was studied in human skeletal remains from archaeological sites in the Santa Barbara Channel area of southern California. These remains were analyzed to better understand changes in activity patterns associated with the economic shift from hunting and gathering to intensive fishing and craft specialization that occurred in this area. The joints of 967 burials from seven archaeological sites occupied between 3500 B.C. and the time of European contact were scored for osteoarthritis. These data show that the rate at which people developed osteoarthritis increased through time. This suggests that the adaptive shift toward more intensive exploitation of the marine environment resulted in an increase in the time people spent in strenuous physical activity. The increase in osteoarthritis affected males to a greater extent than females. One interpretation of this is that the work load of men increased with the economic importance of fishing.     

Small-scale Gold Mining in the Puyango River Basin,Southern Ecuador: A Study of Environmental Impacts andHuman Exposures

This study addresses the impact of small-scale gold mining on the environment and communities of the Puyango River basin in the southwest of Ecuador between 1999 and 2001. Our primary objectives were to measure mercury, manganese, and lead in the river, to identify pathways of population exposure, and biological indicators of human exposure. A multi-method design at the catchment scale was applied to the analysis of water, sediments, and particulate matter for mercury, lead, and manganese over two different seasons. A household survey was undertaken, and individuals were assessed for lead (blood samples), and for mercury (urine and hair samples). River water samples had high concentrations of particulate matter (700 mg/L). Mercury and lead levels in water at the gold processing plants were very high in both seasons (250 ng Hg/L and 160 μg Pb/L). Mercury and lead, there was a downstream gradient with the areas adjacent to the gold processing plants having the highest levels. In Portovelo, the Upper Basin city, 14% of the population reported occupational exposure to inorganic mercury. Although no one in Portovelo consumes water from the river, 10% of the population consume local fish. This contrasts the Lower Basin where 98% of the population consume fish, and 100% use river water for drinking and cooking. Lead blood levels over 20 μg/dl were found in 39.4% of the study population and blood mercury over 10 μg/L only in 10.0%. Urinary mercury over 4 μg/L was found in 66.5% of the examined persons. Hair methylmercury did not exceed the safe limit of 2 μg/g, the mean concentration was 1.2 μg/g. Mining activity and erosion contributes to heavy-metal contamination (mercury, lead, and manganese) throughout the Puyango Basin. The relation between environmental contamination is complex and further research is being conducted to understand these relations.     

Analysis of the region V mitochondrial marker in two Black communities of Ecuador,and in their parental populations

Data on the frequency of the mtDNA region V deletion were used to estimate the relative maternal contribution from the parental populations to the gene pools of the two Black communities of Rio Cayapas and Viche in northern Ecuador. Ethnohistorical records and nuclear DNA data indicate that these populations are hybrids of West African and Amerindian populations. The unique distribution of the DNA marker in these parental groups provided good admixture estimates. The fraction of mtDNA of Amerindian origin in the population of Rio Cayapas is quite small (8%±5%), whereas in the community of Viche the native Americans contributed the major portion of the gene pool (51%±15). The mtDNA estimate for Rio Cayapas is similar to that of some protein polymorphisms, which confirms the cultural and genetic isolation of this community from the neighboring native population. On the other hand, the admixture value obtained from nuclear genes in Viche is statistically different from the estimate obtained from mtDNA data. This supports the traditional belief, gathered from historical records and cultural data, that the contribution from Indian females was higher than that of Indian males, at least in the primary settlements of the African-American population of Esmeraldas.     

Diversity and distribution of type specimens deposited in the Invertebrate section of the Museum of Zoology QCAZ,Quito, Ecuador

The Invertebrate section of the Museum of Zoology QCAZ at the Pontifical Catholic University of Ecuador in Quito maintains nearly two million curated specimens, and comprises Ecuador’s largest collection of native taxa. We review 1902 type specimens from 6 subspecies and 320 species in 121 genera and 42 families, currently kept in the Museum. The list includes 116 holotypes, 10 allotypes, 1774 paratypes and 2 neoparatypes. The collection of type specimens is particularly strong in the Coleoptera (family Carabidae and Staphylinidae) and Hymenoptera. However, other insect orders such as Diptera and Lepidoptera and non-insect arthropods such as Acari, Aranea and Scorpiones, are moderately represented in the collection. This report provides original data from labels of every type specimen record. An analysis of the geographic distribution of type localities showed that collection sites are clustered geographically with most of them found towards the northern region of Ecuador, in Pichincha, Cotopaxi and Napo provinces. Sites are mainly located in highly accessible areas near highways and towns. Localities with a high number of type species include the cloud forest reserve Bosque Integral Otonga and Parque Nacional Yasuní in the Amazon rainforest near PUCE’s Yasuní Scientific Station. Type localities are not well represented in the Ecuadorian National System of Protected Areas. Future fieldwork should include localities in the southern region of Ecuador but also target less accessible areas not located near highways or towns. We discuss the value of the collection as a source of information for conservation and biodiversity policies in Ecuador.     

The effect of land-use on the local distribution of palm species in an Andean rain forest fragment in northwestern Ecuador

The northern Andes is extremely rich in plant species, but this diversity is threatened by extensive deforestation. This study reports on how five palm species respond to human disturbance in an area of montane forest in Ecuador. The abundance of each species was determined in 250 40 × 30m plots, established in disturbed and undisturbed forest within an area of 3 × 3km and altitudes spanning 1248–1938m. Aiphanes erinacea (H. Karst.) H. Wendl. and to a lesser degree Geonoma undata Klotzsch were negatively affected by even moderate human disturbance, while Chamaedorea linearis (Ruiz & Pav.) Mart. and C. pinnatifrons (Jacq.) Oerst. benefitted from such disturbance and Prestoea acuminata (Willd.) H.E. Moore was unaffected given time enough to replenish its population after disturbance. At the scale of the plots, species richness was maximized in undisturbed forest. Aiphanes erinacea is endemic to northern Ecuador and southern Colombia and must be considered threatened by the extensive deforestation here. If the behaviour of these palms is representative of Andean rain forest plans in general, the negative effect of moderate anthropogenic disturbance on plant biodiversity at scales of 1km2 might be negligible. Thus, biologically sustainable logging could be possible.     

Genetic variation of the mitochondrial DNA genome in American Indians is at mutation-drift equilibrium.

Several surveys have found evidence for founder effects in Amerindian mitochondrial DNA because of the existence of rare Asian morphs in high frequencies in some Amerindian populations and the occurrence of several new morphs not seen elsewhere in the world. These reports, however, do not address whether or not the present genetic variation in the mtDNA genome in Amerindians has reached the steady-state distribution predicted by the mutation-drift theory of population genetics. The present work suggests that in three Amerindian populations (Pima, Maya, and Ticuna) a steady state has apparently been reached, and hence the initial founder effect has probably dissipated during the evolution of Amerindians in the New World. This result is consistent with the genetic variation in nuclear genes in similar populations, shown through surveys of protein variation in earlier work and, more recently, in studies of restriction fragment length polymorphisms.     

The Common Property Regime of the Huaorani Indians of Ecuador: Implications and Challenges to Conservation

This paper shows that the Huaorani Indians of the Ecuadorian Amazon possess a long-standing common property management regime fostered by secure ownership status of the land, the small size and kinship ties of residence groups, the existence of mutual trust and reciprocity, and culturally sanctioned rules of behavior. This regime, however, was focused on maintaining harmonious relationships between residents of the nanicabo and not on resource conservation (although it may have fostered epiphenomenal conservation). It cannot be presumed that communal management of resources invariably leads to conservation; other factors need to be present, such as a perception of resource scarcity. The common property regime was designed for a situation of plentiful resources, low population density, clear membership, and behaviors held in check by respect for kin and the desire for good standing. It was a sufficient and simple system for delimiting common property resources from private property, based on implicit social boundaries and cultural understandings. Now, confronted by powerful external forces, population growth, and intermarriage with non-Huaorani, the system is faltering. Conservationist practices, however, can be encouraged by adapting the earlier system to reflect current conditions.     

The role of geography and ecology in shaping the phylogeography of the speckled hummingbird (Adelomyia melanogenys) in Ecuador

The Andes of South America contain one of the richest avifaunas in the world, but little is known about how this diversity arises and is maintained. Variation in mitochondrial DNA and morphology within the speckled hummingbird (Adelomyia melanogenys) was used to elucidate the phylogeographic pattern along an Ecuadorian elevational gradient, from the coastal cordillera to the inland Andean montane region. We examined sequence, climatic/remote sensing and morphological data to understand the effects of topography and ecology on patterns of variation. Populations on either side of the Andes are genetically divergent and were separated during a period that corresponds to the final stages of Andean uplift during the Pliocene. Despite isolation, these two populations were found to be morphologically similar suggesting a strong effect of stabilizing selection across ecologically similar Andean cloud forests, as assessed using climatic and remote sensing data. In contrast, little genetic divergence was found between coastal and west-Andean individuals, suggesting recent interruption of gene flow between these localities. However, coastal populations were found to inhabit different habitats compared to Andean populations as shown by climatic and remote sensing variables. Furthermore, coastal individuals had significantly longer bills compared to their montane relatives, indicative of differential directional selection and the influence of habitat differences in shaping phenotypic variation. Results highlight the role of both isolation and ecology in diversification in Ecuadorian montane regions, while suggesting the two may not always act in concert to produce divergence in adaptive traits.     

Tracing the native ancestors of the modern Theobroma cacao L. population in Ecuador

The native Theobroma cacao L. population from Ecuador, known as Nacional, is famous for its fine cocoa flavour. From the beginning of the twentieth century, however, it has been subjected to genetic erosion due principally to successive introductions of foreign germplasm whose hybrid descendants gradually replaced the native plantations, implying a decrease in cocoa quality. We attempted to trace this native cacao within a wide pool of modern Ecuadorian cacao population. Three hundred and twenty-two cacao accessions collected from different geographical areas along the pacific coast of Ecuador and maintained in two living collections were analysed using 40 simple-sequence repeat markers. Most of Ecuadorian cacao accessions displayed a high diversity and heterozygosity level. A factorial analysis of correspondence (FAC) showed a continuous variation among them, with a few ones, grouped at an extreme side of the FAC cloud, showing higher levels of homozygosity and lower introgression level by foreign cacaos. A paternity analysis revealed that these highly homozygous individuals are the most probable ancestors of the modern Nacional hybrid pool. These particular accessions studied could represent the native Nacional cacao present in Ecuador before the foreign introductions. Their identification will help to conserve valuable genetic material and to improve cocoa quality in new cacao varieties.     

HLA class II linkage disequilibrium and haplotype evolution in the Cayapa Indians of Ecuador.

DNA-based typing of the HLA class II loci in a sample of the Cayapa Indians of Ecuador reveals several lines of evidence that selection has operated to maintain and to diversify the existing level of polymorphism in the class II region. As has been noticed for other Native American groups, the overall level of polymorphism at the DRB1, DQA1, DQB1, and DPB1 loci is reduced relative to that found in other human populations. Nonetheless, the relative evenness in the distribution of allele frequencies at each of the four loci points to the role of balancing selection in the maintenance of the polymorphism. The DQA1 and DQB1 loci, in particular, have near-maximum departures from the neutrality model, which suggests that balancing selection has been especially strong in these cases. Several novel DQA1-DQB1 haplotypes and the discovery of a new DRB1 allele demonstrate an evolutionary tendency favoring the diversification of class II alleles and haplotypes. The recombination interval between the centromeric DPB1 locus and the other class II loci will, in the absence of other forces such as selection, reduce disequilibrium across this region. However, nearly all common alleles were found to be part of DR-DP haplotypes in strong disequilibrium, consistent with the recent action of selection acting on these haplotypes in the Cayapa.