Immunoglobulin (GM and KM) allotypes and relation to population history in native peoples of British Columbia: Haida and Bella Coola

Differences in the frequencies of GM haplotypes among native peoples of the Americas support the hypothesis that there were three distinct waves of migration from northeast Asia into the Americas: Paleo-Indian, Na-Dene, and Inuit (Eskimo)-Aleut (Salzano and Steinberg: Am. J. Hum. Genet. 17:273-279, 1965; Sukernik and Osipova: Hum. Genet. 61:148-153, 1982; Williams et al.:Am. J. Phys. Anthropol. 66:1-19, 1985; Szathmary: In R Kirk and E Szathmary (eds): Out of Asia: Peopling of the Americas and the Pacific. Canberra: The Journal of Pacific History, Canberra Australian National University, pp. 79-104, 1985). We studied GM allotypes in two linguistically unique populations of Canadian west coast native peoples, the Haida and the Bella Coola, and compared them to GM frequencies in populations that are supposed descendants of the three migrations, in order to investigate the possible genetic relationships of these British Columbia (BC) groups to other native populations. We also estimated the amount of European admixture from the frequency of the Caucasian haplotype, Gm3;5. Results showed that the frequencies in both BC populations of the three common native haplotypes (Gm1,17;21, Gm1,2,17;21, and Gm1,17;15,16), were intermediate between the frequencies in supposed descendants of Paleo-Indian and Na-Dene. These genetic findings are consistent with the controversial hypothesis of archeologist C. Borden (Science 203:963-971, 1979) that, following deglaciation about 13,000 years ago, British Columbia was repopulated by peoples from the north (?Na-Dene) and by culturally distinct peoples from the south (?Paleo-Indian). Caucasian admixture estimates suggested that the Haida and Bella Coola have also experienced moderate amounts (12-20%) of genetic input from European-originating peoples.(ABSTRACT TRUNCATED AT 250 WORDS)     

Genetical and biochemical comparisons of alcohol dehydrogenase isozymes from Anastrepha fraterculus and A. obliqua (Diptera: Tephritidae): Evidence for gene duplication

The electrophoretic patterns of the enzyme alcohol dehydrogenase (ADH) from Anastrepha fraterculus and A. obliqua were studied. Two loci were found to code for the enzyme in A. fraterculus, and three in A. obliqua. In both species, all isozymes were active in third-instar larvae. A cationic isozyme (Adh-1) was active mainly in the visceral fat body of both species. In A. fraterculus, the locus had an anionic polymorphic isozyme (Adh-3) that was detected in the parietal fat body. In addition to these two loci, a third locus for an anionic isozyme (Adh-2), which was active in the digestive tube of larvae, was present in A. obliqua and probably resulted from gene duplication. For both species, multiple forms of the isozymes are formed by binding of an NAD-carbonyl compound, as in Drosophila melanogaster. Both larvae and early pupae of A. obliqua had almost twice the specific ADH activity as A. fraterculus. The ethanol content of the host fruit infested with A. obliqua (red mombim) was also higher than that of the host fruit infested with A. fraterculus (guava).This research was supported by grants from Conselho Nacional de Desenvolvimento Científico e Tecnologico (CNPq-PIG 40.2486/82).     

Dramatic founder effects in Amerindian mitochondrial DNAs

Southwestern American Indian (Amerindian) mitochondrial DNAs (mtDNAs) were analyzed with restriction endonucleases and found to contain Asian restriction fragment length polymorphisms (RFLPs) but at frequencies very different from those found in Asia. One rare Asian HincII RFLP was found in 40% of the Amerindians. Several mtDNAs were discovered which have not yet been observed on other continents and different tribes were found to have distinctive mtDNAs. Since the mtDNA is inherited exclusively through the maternal lineage, these results suggest that Amerindian tribes were founded by small numbers of female lineages and that new mutations have been fixed in these lineages since their separation from Asia.     

Effects of fire,topography and year-to-year climatic variation on species composition in tallgrass prairie

Native unploughed tallgrass prairie from Konza Prairie, Kansas, USA is described with respect to plant species compositional changes over a five year period in response to fire and topography. The principal gradient of variation in the vegetation is related to time since burning. Species show an individualistic response in terms of relative abundance to this gradient. Both the percentage of and cover of C₄ species and all grasses decrease as the prairie remains unburnt. Forb and woody plant species numbers and abundance increase along this gradient. A secondary gradient of variation reflects topography (i.e. upland versus lowland soils). Upland soils support a higher species richness and diversity. Upland and lowland plant assemblages are distinct except on annually burnt prairie. The interaction between burning regime, topography and year-to-year climatic variation affects the relative abundance of the plant species differentially. The most dominant species overall, Andropogon gerardii, was affected only by year-to-year variation (i.e. climate). Its position at the top of the species abundance hierarchy was unaffected by burning regime or soil type. The other dominant species showed a suite of varying responses to these factors.Deceased May, 1986.     

Temporal constancy in grasshopper assemblies (Orthoptera: Acrididae)

ABSTRACT.

• 1 Temporal constancy in the structure of grasshopper assemblies (about forty-five species each) from two types of North American grasslands was assessed; one site was followed 25 years and the other 7 years.
• 2 Densities and relative abundances varied but composition of assemblies based on ranks suggested significant structure when three or more species were included in the analysis.
• 3 Results compared favourably with other insect herbivore assemblies which have been examined; variability in population change was intermediate along the spectrum of organisms which have been studied.

     

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.     

Comparison of axonemal proteins from two kinds of Tetrahymena. I. Different characteristics of dyneins in heat stability

Tetrahymena thermophila could still swim after incubation of the cell body at 40°C for 30 min, whereas Tetrahymena pyriformis did not show any motility after the treatment. Turbidity measurements revealed that axonemes of T. pyriformis lost ATP-dependent sliding activity by the heat treatment, whereas those of T. thermophilia still had the activity under the same conditions. In connection with this difference in susceptibility to high temperature, the biochemical characteristics of dyneins were compared between the two species of Tetrahymena. Axonemal dyneins from the two species had significant vanadate-sensitive ATPase activity even after the heat treatment. Native gel electrophoresis and the following two-dimensional electrophoresis showed that the outer arm dynein of T. thermophilia is more stable in maintaining native configuration than that of T. pyriformis against the heat treatment, although both treated dyneins keep three (α, β and γ) subunits. Analysis by peptide mapping demonstrated that β- and γ-subunits of the outer arm dynein are considerably different in amino acid sequences between the two species. These results imply that dynein of T. thermophilia changed their amino acid sequences and biochemical characteristics to adapt to high temperature.     

Ernst Mayr as community architect: Launching the society for the study of evolution and the journalEvolution

Ernst Mayr's contributions to 20th century biology extend far beyond his defense of certain elements in evolutionary theory. At the center of mid-century efforts in American evolutionary studies to build large research communities, Mayr spearheaded campaigns to create a Society for the Study of Evolution and a dedicated journal,Evolution, in 1946. Begun to offset the prominence ofDrosophila biology and evolutionary genetics, these campaigns changed course repeatedly, as impediments appeared, tactics shifted, and compromises built a growing coalition of support. Preserved, however, were designs to balance the community and journal with careful equation of status and explicit partitioning of responsibilities within the working coalition. Choice terms such as cooperation and unity carried a strong political message. Mayr's editorship ofEvolution provides a superb example of these balancing efforts. The mid-century infrastructural activities described herein also represented aggressive attempts to leverage control across several layers of community. Leaders of these campaigns sought: (1) to promote evolutionary studies as a modernized research discipline and place it at the center of American biology, (2) to promote evolutionary studies within existing disciplines — e.g. systematics, genetics, and paleontology, (3) to foster certain research styles within evolutionary studies, and (4) to emphasize certain solutions to prominent research questions. Throughout, Mayr interjected his priorities, tactics and energy.     

Differences in physical growth of Aymara and Quechua children living at high altitude in Peru

Physical growth of Amerindian children living in two Aymara and three Quechua peasant communities in the Andean highlands of southern Peru (altitude 3,810–3,840 m) was studied, taking into account differences in the microclimate, agronomic situation, and sociodemographic variables. Anthropometric measurements were taken in 395 children aged under 14 years of age in a sample of 151 families in these communities, who were surveyed for sociodemographic variables as well. Data on the land system were available for 77 families. In comparison with reference populations from the United States (NCHS) and The Netherlands, stature, weight, head circumference, and midupper arm circumference (but not weight for stature) in the sample children were reduced. Growth retardation increased after the age of 1 year. Stature and weight in the present sample were very similar compared with previously published data on growth of rural Aymara children living near Lake Titicaca in Bolivia. Head circumference, midupper arm circumference, and weight for stature were significantly larger in Aymara children compared with Quechua children. Land was significantly more fragmented in Aymara compared with Quechua families, but amount of land owned was not different. Perinatal and infant mortality was elevated in Aymara vs. Quechua communities. Most families in Aymara communities used protected drinking water. One Quechua community had a severe microclimate, grim economic outlook, and weak social cohesion. Children in this community showed significant reductions in weight and midupper arm circumference compared with their peers in the other communities. We conclude that (presumably nutritionally mediated) intervillage and Aymara-Quechua differences in childhood physical growth existed in this rural high-altitude population in Peru and were associated with microclimate and the village economy, sociodemographic factors, and differences in the land system. © 1993 Wiley-Liss, Inc.