A Sensory Ecology of Medicinal Plant Therapy in Two Amazonian Societies

Sensory anthropology has explored sensation as a fruitful but poorly examined domain of cross-cultural research. Curiously, sensory anthropologists have mostly ignored scientific research into sensation, even that which addresses cross-cultural variation. A comparative study in two Amazonian societies (Matsigenka, Yora [Nahua]) documented the role of the senses in medicinal plant therapy and benefited greatly from theoretical insights gleaned from sensory science. The study reveals a complex interweaving of cultural and ecological factors in medicinal plant selection, with sensation standing at the culture--nature nexus linking medical ideas with medical materials. By synthesizing (rather than antagonizing) scientific and anthropological insights, sensation can be understood as a biocultural phenomenon rooted in human physiology yet constructed through individual experience and culture. Overcoming the limitations of a narrowly defined sensory anthropology, sensory ecology is here proposed as a new theoretical perspective for addressing human--environment interactions mediated by the senses.     

Intraspecific DNA sequence variation of the mitochondrial control region of white sturgeon (Acipenser transmontanus)

Intraspecific sequence variation in the D-loop region of mtDNA in white sturgeon (Acipenser transmontanus), a relict North American fish species, was examined in 27 individuals from populations of the Columbia and Fraser rivers. Thirty-three varied nucleotide positions were present in a 462-nucleotide D-loop sequence, amplified using the polymerase chain reaction. Bootstrapped neighbor-joining and maximum- parsimony trees of sequences from 19 haplotypes suggest that the two populations have recently diverged. This is consistent with the hypothesis that the Columbia River, a Pleistocene refugium habitat, was the source of founders for the Fraser River after the last glacial recession. On the basis of a divergence time of 10-12 thousand years ago, the estimated substitution rate of the white sturgeon D-loop region is 1.1-1.3 x 10(-7) nucleotides/site/year, which is comparable to rates for hypervariable sequences in the human D-loop region. Furthermore, the ratio of mean percent nucleotide differences in the D- loop (2.27%) to that in whole mtDNA (0.54%, as estimated from restriction-enzyme data) is 4.3, which is similar to the fourfold-to- fivefold-higher substitution rate estimated for the human D-loop. The high nucleotide substitution rate of the hypervariable region indicates that the vertebrate D-loop has potential as a genetic marker in molecular population studies.      

Above-ground competition does not alter biomass allocated to roots in Abutilon theophrasti

We tested whether plants allocate proportionately less biomass to roots in response to above-ground competition as predicted by optimal partitioning theory. Two population densities of Abutilon theophrasti were achieved by planting one individual per pot and varying spacing among pots so that plants in the two densities experienced the same soil volume but different degrees of canopy overlap. Density did not affect root:shoot ratio, the partitioning of biomass between fine roots and storage roots, fine root length, or root specific length. Plants growing in high density exhibited typical above-ground responses to neighbours, having higher ratios of stem to leaf biomass and greater leaf specific area than those growing in low density. Total root biomass and shoot biomass were highly correlated. However, storage root biomass was more strongly correlated with shoot biomass than was fine-root biomass. Fine-root length was correlated with above-ground biomass only for the small subcanopy plants in crowded populations. Because leaf surface area increased with biomass, the ratio between absorptive root surface area and transpirational leaf surface area declined with plant size, a relationship that could make larger plants more susceptible to drought. We conclude that A. theophrasti does not reallocate biomass from roots to shoots in response to above-ground competition even though much root biomass is apparently involved in storage and not in resource acquisition.     

Population genetic variation in rare and endangered Iliamna (Malvaceae) in Virginia

Random amplified polymorphic DNA (RAPD) markers were used as input for an analysis of molecular variance (AMOVA), homogeneity of molecular variance analysis (HOMOVA), and cluster analysis to describe the population genetic structure of Iliamna corei, a federally endangered plant located only in Virginia, and I. remota , a rare plant in Virginia, Indiana, and Illinois. The analysis was performed to help clarify the taxonomic relationship between the two closely related species. We analysed four clones in the only known population of I. corei , breeding stock derived from seeds originating from the population site, and three I. remota populations in Virginia. Eighty-five percent of screened primers revealed DNA polymorphisms in Iliamna. Ninety-nine informative markers were generated using seven primers. No significant statistical differences (at P = 0.05) in RAPD variation was found between species (24% of variance) using the AMOVA procedure. However, within species/among populations (31 % of the variance) and within populations (45% of the variance) there were significant differences (P < 0.002). An unweighted paired group method using arithmetic averages (UPGMA) cluster analysis showed the federally endangered I. corei population to be genetically distinct from the apparently recently introduced (in Virginia: ∼ 100 ybp) I. remota. The lack of significant differences from the AMOVA and the high number shared bands between I. corei and I. remota suggest that I. corei may be more appropriately classified as a subspecies of I. remota. Iliamna corei plants in the natural population were genetically similar to one another while the I. corei breeding stock plants and I. remota plants were genetically relatively diverse.