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Coastal Desert (coastal + desert)
Selected AbstractsKaryotype analysis and polyploidy in Palaua and a comparison with its sister group Fuertesimalva (Malvaceae)JOURNAL OF SYSTEMATICS EVOLUTION, Issue 3 2010Julio V SCHNEIDER Abstract,Palaua (Malveae, Malvaceae) comprises 15 species endemic to the hyperarid coastal desert of Chile and Peru. So far, chromosome counts have been known for two diploid species (2n= 2x= 10) only. Here we report new chromosome numbers for 12 species of Palaua and four of its sister group Fuertesimalva. Karyotypes including 4,,6,-diamidino-2-phenylindole dihydrochloride (DAPI)/chromomycin (CMA3) fluorescent banding are presented for selected species representative of each of the main clades of Palaua. An important finding is the discovery of polyploids in one exclusively tetraploid species (P. trisepala) and four species with mixed diploid and tetraploid cytotypes (P. dissecta, P. mollendoensis, P. moschata, and P. tomentosa). The diploid and tetraploid karyotypes are all unimodal, symmetrical and show one or two pairs of satellite chromosomes with their associated CMA+/DAPI, band depending on the cytotype. For some of the tetraploids an autopolyploid origin is suggested. [source] The usefulness of caries frequency, depth, and location in determining cariogenicity and past subsistence: A test on early and later agriculturalists from the Peruvian coastAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010Luis Pezo Lanfranco Abstract Dental markers have been used to unravel particularities of paleodiet, subsistence, social structure, and health. This article aims to compare oral pathology among four pre-Columbian groups with different degrees of agricultural and socio-cultural development but comparable ecological conditions who lived on the coastal desert of Peru. Three of these groups are assigned to distinct phases of the Formative Period (2500,1 BC), a time critical for our understanding of the development of agriculture and social complexity. The fourth group corresponds to the Late Intermediate Period (1000,1470 AD), when agriculture had its apogee and society was highly stratified. In this study we test whether there is an increase (1) in the frequency of carious lesions and (2) in caries depth, and (3) if there is a shift from occlusal to extra-occlusal caries locations with the development of agriculture. Therefore, we analyze the frequencies of carious lesions and antemortem tooth loss (AMTL), the caries distributions by age, sex, and type of tooth, as well as the tissues affected by, and the location of the carious lesions. Since there are no significant differences in the frequencies of carious lesions and AMTL between the groups, we reject hypothesis 1. In contrast, caries depth does increase, and caries location changes from occlusal to extra-occlusal sites with agricultural development. However, we can only corroborate hypothesis 2 and 3 when taking into consideration dental wear. Thus, we recommend that caries depth and locations should be used with evaluations of dental wear to reconstruct subsistence in ancient populations. Am J Phys Anthropol 143:75,91, 2010. © 2010 Wiley-Liss, Inc. [source] Cybrids and tetrad sterility for developing true potato seed hybridsANNALS OF APPLIED BIOLOGY, Issue 2 2003ALI M GOLMIRZAIE Summary Potato cybrids result from the fusion between cytoplasm and nuclear gene donors. Such genetic materials are an alternative means to broaden the breeding pool by non-sexual gene transfer. Tetrad pollen sterility provides also another source of male sterility with some potential for true potato seed breeding. The objective of this research was to investigate cybrid-derived offspring for both agronomic and reproductive characteristics in two contrasting Peruvian locations, and to examine new exotic germplasm for tetrad sterility, with the aim of broadening the breeding pool available at the Centro Internacional de la Papa (CIP). The cybrids were derived from fusions between Y-245.7, a clone with tetrad sterility, and Atzimba. These cybrids were crossed with selected male parents from the CIP breeding population, and their hybrid offspring were tested in La Molina (coastal desert) and Huancayo (cool highlands). In addition, other clones with tetrad sterility were also crossed with selected testers to determine their breeding value. There were significant differences for tuber yield, style length, and berry number among the hybrid offspring, and the genotype by environment interaction was significant for tuber yield and berry number. The top 25% highest yielding cybrid-derived offspring across both locations showed the same tuber yield although they were significantly different for some of the reproductive characteristics. With the exception of one cybrid, the others did not exhibit segregation for tetrad sterility in their hybrid offspring, which were male fertile. However, the offspring derived from crosses between other sources of tetrad sterility and the same testers all showed tetrad sterility, and some of them had outstanding tuber yield at La Molina. The lack of segregation for tetrad sterility in these new crosses suggests that the non-cybrid, male sterile, female parents are triplex or quadriplex for the Tr nuclear locus, which interacts with a sensitive cytoplasm (e.g. Trs from S. verrucosum or S. stoloniferum) to produce tetrad sterility in potato. [source] Why is there discordant diversity in sengi (Mammalia: Afrotheria: Macroscelidea) taxonomy and ecology?AFRICAN JOURNAL OF ECOLOGY, Issue 1 2009Galen B. Rathbun Abstract The seventeen species of sengis or elephant-shrews form a well-defined clade of mammals endemic to Africa that occupy the extremes of terrestrial habitats, from coastal deserts to montane forests. Because of their isolation on Africa soon after the break-up of Gondwanaland, theoretically sengis initially evolved with little competition from other placental radiations. Their life history features include myrmecophagy, saltatorial gaits, no or limited use of nests, social monogamy, small litters of precocial young and absentee maternal care of neonates. These traits together are unique to the Macroscelidea and represent a wedding of features usually associated with either small antelopes or anteaters. Combined, these features define an adaptive syndrome that presumably has been relatively immune to competition from contemporary mammals, partially due to phylogenetic inertia. Yet paradoxically, the syndrome is well suited to a wide range of terrestrial habitats, resulting in low taxonomic diversity. Because of their unusual phylogeny and low species diversity, conservation interest is high for those sengis with relatively low densities in fragmented forests. Résumé Les 17 espèces de sengis (musaraignes éléphants) forment un clade bien déterminé de mammifères endémiques d'Afrique, qui occupe des habitats terrestres extrêmes allant de déserts côtiers à des forêts de montagne. En raison de leur isolement sur le continent africain très vite après la scission du Gondwana, les sengis ont théoriquement évolué au départ sans qu'il existe beaucoup de compétition avec les radiations d'autres placentaires. Les caractéristiques de leur histoire incluent de la myrmécophagie, des déplacements par bonds, un usage de nids limité, voire inexistant, la monogamie sociale, de petites portées de jeunes précoces et l'inexistence de soins maternels pour les nouveau-nés. Toutes ces caractéristiques sont uniques pour les Macroscélidés et représentent un regroupement de caractéristiques d'habitude associées à de petites antilopes ou à des fourmiliers. Combinées, ces caractéristiques définissent un syndrome d'adaptation qui, sans doute, fut relativement protégé de toute compétition avec des mammifères contemporains, à cause, en partie, de l'inertie phylogénétique. Mais, paradoxalement, ce syndrome est bien adaptéà une vaste gamme d'habitats terrestres, ce qui n'entraîne donc qu'une faible diversité taxonomique. En raison de leur phylogenèse inhabituelle et de la faible diversité entre ces espèces, l'intérêt de la conservation est considérable pour ces sengis dont la densité, dans des forêts fragmentées, est relativement faible. [source] | ||||||||||