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1.
Surplus production is a hallmark of Alaska's prehistoric coastal societies. Over the millennia, foragers procured greater quantities of resources with increasing efficiency, developing economies dependent upon storage and institutionalized exchange. In the central Gulf of Alaska, notable evidence of surplus production comes from the late phase of the Kachemak tradition. Since de Laguna's pioneering studies, archaeologists have noted that intensified fishing, storage, and exchange typify this tradition. However, few have investigated the roots of these behaviors. When, how, and why did foragers begin producing well beyond immediate needs? This paper explores archaeological evidence for surplus production in the Kodiak Archipelago, focusing on patterns in land use, technology, and exchange preserved in Ocean Bay II and Early Kachemak assemblages from the Chiniak Bay region. It suggests that surplus production for the purposes of seasonal food storage began in the Early Kachemak, and accelerated in the Late Kachemak as population levels climbed.  相似文献   

2.
The sediment stratigraphy of a medium-sized mixotrophic lake (Ruila) situated below the highest shoreline of the Baltic Ice Lake in the West-Estonian Lowland is described. The lake is without natural inlets our outlets. The reconstruction of vegetation and land-use history based on pollen data, combined with available archaeological data and detailed 14C dating allows us to give a provisional reconstruction of the temporal and spatial pattern of natural and human induced environmental changes in north-west Estonia during the Holocene. Both radiocarbon dates derived from terrestrial macrofossil dating by accelerator mass spectrometry (AMS) and conventional dating of bulk lake sediment are discussed. The isolation of the lake basin from the Yoldia Sea took place ca. 9700 cal B. C. The Ancylus Lake transgression at ca. 8400 cal B. C. did not reach the basin, but caused a ground water rise, seen in the sediment stratigraphy of the lake. The first signs of human impact on the pollen record appear ca. 5400 cal B. C. (Late Mesolithic). The history of arable farming has been divided into three periods: 1) introduction of crop cultivation and animal husbandry (1500 cal B. C. – A. D. 500); 2) establishment of animal husbandry A. D. 500–1000) and 3) establishment of crop cultivation and intensive cattle breeding (A. D. 1000–today). Due to unfavourable eda-phic conditions the introduction of arable farming was delayed for more than 1000 years compared with elsewhere on the north coast of Esotnia, and intensity of land-use never reached the same proportion as in these areas. Received August 15, 2001 / Accepted August 5, 2002 Correspondence to: Leili Saarse  相似文献   

3.
The effects of agricultural intensification on health are examined in prehistoric populations of the Valley of Oaxaca, Mexico. Agriculture was practiced in the Valley of Oaxaca by the beginning of the Early Formative period (ca. 1400 B.C.), and had intensified by the Late Formative (ca. 500 B.C.). Skeletal remains from 14 archaeological sites in the Valley are pooled by temporal affiliation into a nonintensive agriculture group (1400-500 B.C.) and an intensive agriculture group (500 B.C.-1400 A.D.). The health effects of agricultural intensification are assessed by comparing the frequency of periosteal reactions, cribra orbitalia, and enamel hypoplasia between the intensive and nonintensive agricultural groups. Overall, no significant differences (alpha = 0.05) are found between the nonintensive and intensive groups. Power analyses of the chi-square tests indicate that the tests have a high probability of rejecting a false null hypothesis. The intensification of agriculture does not appear to have had a deleterious effect on the health of the prehistoric population of the Valley. The differences between this study and previous studies of health and agricultural development may be explained by differences between the processes of intensification and development or by differences between primary and secondary centers of agricultural development.  相似文献   

4.
Pollen analysis was carried out on gyttja from the small lake Femtingagölen in the Småland Uplands, southern Sweden. The interpretation of the pollen diagram focused on land-use history and comparisons were made to archaeological and historical information from the area. An absolute chronology, based on AMS dates from terrestrial plant macrofossils, was complemented by inferred dates. The pollen analytical data suggest interference with the woodland cover from ca. 1700 B.C. onwards. Intensified grazing and forest clearances resulted in semi-open pastures between ca. A.D. 400–600 which was followed by forest regeneration (chronology based on AMS 14C dates and cross-correlation with other well dated profiles). The landscape became more open again between A.D. 800 and 1400. Animal husbandry was complemented by small-scale shifting cultivation during the Iron Age. Permanent arable fields were probably not introduced until the Late Iron Age or the Middle Ages. Hordeum and Triticum were grown during the Iron Age, Hordeum, Triticum, Secale and Cannabis sativa during the Middle Ages and early Modern time, and Hordeum and Avena in the recent past. Sandy and silty soils, where stone clearance was not necessary, have probably been used for cereal growing in prehistoric and historic time.  相似文献   

5.
《Plains anthropologist》2013,58(78):59-82
Abstract

Chronology has long been a major concern of researchers in the Middle Missouri Subarea. However, the paucity of radiocarbon dates, as well as the general lack of multiple dates for many components, has hampered comprehensive assessment and interpretation of culture-historical sequences. A large number of radiocarbon dates pertaining to the Middle Missouri Tradition has become available over the last several years, and presently at least 124 dates are available from both published and unpublished sources for 36 components of the tradition. Dates for each radiocarbon-dated Middle Missouri Tradition component in the Big Bend, Bad-Cheyenne, Cannonball, and Knife-Heart Regions – a total of 111 dates for 33 components – are assessed and averaged according to techniques recently advanced by Bruce Rippeteau and Austin Long. Tentative occupational sequences for each of these regions are offered and problems with specific date series are discussed. Dates for components in the Grand-Moreau Region and the James River valley are also discussed, but are not fitted into sequence. Lehmer’s earlier postulation of a gap in the Bad-Cheyenne sequence at about A.D. 1300 is supported by this analysis, and the presence of a similar hiatus is suggested for the Cannonball Region.  相似文献   

6.
Radiocarbon dates from the terrestrial Weichselian standard profile of Oerel are presented. The end of the Early Weichselian (WE IV, corresponding to isotopic stage 5a) is dated by two independent analyses to around 61 000 years B.P. The two subsequent interstadials, Oerel and Glinde, which have been described from this locality in an earlier publication, are dated to ca. 58 000 - 54 000 B.P. and 51 000- 48 000 B.P., respectively. The dates of both interstadials are in good agreement with the chronology available from the deep sea record. The chronology of the younger part of the Pleni-Weichselian is briefly reviewed.  相似文献   

7.
Brooke, R.K., Allan, D.G., Cooper, J., Cyrus, D.P., Dean, W.R.J., Dyer, B.M., Martin, A.P. & Taylor, R.H. 1999. Breeding distribution, population size and conservation of the Greyheaded Gull Larus cirrocephalus in southern Africa. Ostrich 70 (3&4): 157–163.

The Greyheaded Gull Larus cirrocephalus occurs throughout southern Africa, both coastally and inland, and has bred at one time or another at 67 known localities since the 1860s. Most of these sites have been occupied by small numbers of birds, even single pairs, and for only one or a few years. The two principal breeding areas are the East Rand in Gauteng and Lake St Lucia in KwaZulu-Natal, both in South Africa. The next most important sites are Walvis Bay, Namibia and Lake Ngami, Botswana. The total southern African breeding population is estimated as about 2000 pairs. The Greyheaded Gull is not a threatened species in southern Africa, with 27 breeding sites supporting more than half the breeding population within formally conserved areas.  相似文献   

8.
Effect of cyanobacterial blooms on thermal stratification   总被引:2,自引:0,他引:2  
Enclosure experiments were performed at Akanoi Bay, Lake Biwa, in 1995 to determine whether the blooms of cyanobacterial algae changed thermal stratification in the lake. We used four rectangular enclosures, each 10 m × 10 m, with a volume of 200 m3, which were open to the sediments. Two enclosures, A and B, were mixed artificially by aquatic pumps from 1000 to 1400 every day, and the other two enclosures, C and D, were controls with no mixing. The experiment was conducted during late summer from August 3 to September 27. Chlorophyll a concentrations were highest in enclosure D, followed by enclosure C, both of which were controls without mixing. Enclosure A had lower concentrations than enclosures C and D, and enclosure B had the lowest concentrations. No large cyanobacterial algae blooms of Anabaena sp. and Microcystis sp. were seen in the mixed enclosures A and B. In enclosures C and D, blooms of Anabaena sp. occurred in the middle of August, and Microcystis sp. later became dominant in enclosure D at the end of August. In enclosure D, the water temperature changed over the diel cycle before August 17, with thermal stratification during the day and complete mixing at night. After August 17, as Anabaena sp. and Microcystis sp. became dominant, the temperature at the bottom of the enclosure did not change clearly over the 24-h cycle. The APE (available potential energy) density (a measure of water column stability) in the enclosures increased by almost 100% when the biovolume of Anabaena sp. + Microcystis sp. exceeded 20 mm3 l−1. These results indicate that blooms of Anabaena sp. and Microcystis sp. can increase the available potential energy in the water column and create more stable stratification for their growth. Received: September 25, 1999 / Accepted: January 6, 2000  相似文献   

9.
《Plains anthropologist》2013,58(73):181-186
Abstract

A unique rockshelter burial in southwestern Texas contained a 35 year old male placed in asitting position in a pit lined with matting. Remains of a woven stick and grass structure were over the burial pit. Affiliation is late Archaic and dates ca. 200 B.C.-A.D. 200.  相似文献   

10.
The anterior half of the mitochondrial DNA control region (mtCR) sequence (ca. 400 base pairs) was compared between two color morphotypes (A, B) of Parapercis sexfasciata from Tosa Bay, southern Japan, using 16 and 21 specimens, respectively. Intramorphotypic mtCR divergences were only 0.0–0.5% and 1.0–2.5% for morphotypes A and B, respectively. In contrast, intermorphotypic mtCR divergence was much greater, 12.7–14.0%. Furthermore, phylogenetic analysis using a neighbor-joining algorithm, with P. multifasciata as an outgroup, showed that each morphotype was reciprocally monophyletic. These results and the distinct coloration and overlapping distribution indicate that the two color morphotypes of P. sexfasciata represent two distinct species. Mismatch distribution analysis suggested that both morphotypes had undergone population expansion; however, estimates of initial population sizes and mutational timescales suggested that morphotype B comprises historically larger and older populations than morphotype A.  相似文献   

11.
We examined genetic differences of four Vitis vinifera populations (A, B, C, D) including local Kabarcik cultivar grown along an altitude gradient of 800, 900, 1000, and 1150 m above sea level in the Coruh Valley (800 m: A population; 900 m: B population; 1000 m: C population; 1150 m: D population). Leaf samples were used for both RAPD and fatty acid analysis. A total of 60 individuals with 15 individuals per population were included in this study. RAPD analyses showed various band sizes, which ranged from 250 to 3000 bp. Mean polymorphic locus ratios were determined as 96.29% considering four populations. The highest percentage of polymorphic loci (97.8%) was produced by the highest altitude. Thirty-two different fatty acids were found; linoleic acid was the most common in all four populations. According to the dendograms obtained from statistical analyses of RAPD and fatty acid profiles the populations that were close to each other in terms of geographical distance also were similar genetically.  相似文献   

12.
Relatively little is known about the genetic control of agronomic traits in common wheat (Triticum aestivum L.) compared with traits that follow Mendelian segregation patterns. A doubled-haploid population was generated from the cross RL4452x'AC Domain' to study the inheritance of the agronomic traits: plant height, time to maturity, lodging, grain yield, test weight, and 1000-grain weight. This cross includes the genetics of 2 western Canadian wheat marketing classes. Composite interval mapping was conducted with a microsatellite linkage map, incorporating 369 loci, and phenotypic data from multiple Manitoba environments. The plant height quantitative trait loci (QTLs), QHt.crc-4B and QHt.crc-4D, mapped to the expected locations of Rht-B1 and Rht-D1. These QTLs were responsible for most of the variation in plant height and were associated with other agronomic traits. An additional 25 agronomic QTLs were detected in the RL4452x'AC Domain' population beyond those associated with QHt.crc-4B and QHt.crc-4D. 'AC Domain' contributed 4 alleles for early maturity, including a major time to maturity QTL on 7D. RL4452 contributed 2 major alleles for increased grain yield at QYld.crc-2B and QYld.crc-4A, which are potential targets for marker-assisted selection. A key test weight QTL was detected on 3B and prominent 1000-grain weight QTLs were identified on 3D and 4A.  相似文献   

13.
High resolution pollen data from two mires in the Rukiga Highlands, southwest Uganda (Ahakagyezi Swamp and Muchoya Swamp) provide detailed evidence of the environmetal history of the region since ca. 42 000 yr B.P. According to these data, there a was period pre ca. 42 000 yr B.P.>. when climatic conditions were similar to the present. Conditions considerably colder and drier than the present occurred during two periods in the past (pre ca. 42 000 yr B.P. to ca. 32 000 yr B.P., and ca. 21 000 yr B.P. to ca. 12 000 yr B.P.). The most recent period of climatic improvement began ca. 14 000 yr B.P. Moist lower montane forest colonised the Muchoya catchment by ca. 11 100 yr B.P. and the Ahakagyezi catchment by ca. 10 600 yr B.P. indicating the establishment there of climatic conditions broadly similar to the present.

Pollen data from both mires reveal forest disturbances beginning ca. 2200 yr B.P. This disturbances is likely to have been human-induced.  相似文献   


14.
胶州湾西部海域大型底栖动物次级生产力初步研究   总被引:12,自引:2,他引:12  
2003年9月—2004年9月隔月在胶州湾西部的5个站位进行了7个航次的大型底栖动物调查取样.利用Brey经验公式对大型底栖动物的丰度、生物量、次级生产力和P/B值进行研究.结果表明,该海域大型底栖生物年次级生产力平均值为47.34 g·m-2·a-1.平均P/B值为0.58.相关分析表明,叶绿素a是影响次级生产力的重要因子,与南黄海鳀鱼产卵场、渤海及国外相关海域的结果进行比较表明,在局域尺度上叶绿素a是最重要的影响因子,但在区域尺度上次级生产力随水深增加而降低.分析对次级生产力影响最大的菲律宾蛤仔种群的年龄组成发现,该种群主要是由不足1龄、1龄和2龄个体组成.  相似文献   

15.
Vegetation history for the study region is reconstructed on the basis of pollen, charcoal and AMS14C investigations of lake sediments from Lago del Segrino (calcareous bedrock) and Lago di Muzzano (siliceous bedrock). Late-glacial forests were characterised byBetula andPinus sylvestris. At the beginning of the Holocene they were replaced by temperate continental forest and shrub communities. A special type of temperate lowland forest, withAbies alba as the most important tree, was present in the period 8300 to 4500 B.P. Subsequently,Fagus, Quercus andAlnus glutinosa were the main forest components andA. alba ceased to be of importance.Castanea sativa andJuglans regia were probably introduced after forest clearance by fire during the first century A.D. On soils derived from siliceous bedrock,C. sativa was already dominant at ca. A.D. 200 (A.D. dates are in calendar years). In limestone areas, however,C. sativa failed to achieve a dominant role. After the introduction ofC. sativa, the main trees were initially oak (Quercus spp.) and later the walnut (Juglans regia). Ostrya carpinifolia became the dominant tree around Lago del Segrino only in the last 100–200 years though it had spread into the area at ca. 5000 cal. B.C. This recent expansion ofOstrya is confirmed at other sites and appears to be controlled by human disturbances involving especially clearance. It is argued that these forests should not be regarded as climax communities. It is suggested that under undisturbed succession they would develop into mixed deciduous forests consisting ofFraxinus excelsior, Tilia, Ulmus, Quercus andAcer.  相似文献   

16.
A pollen diagram from the Ahlequellmoor in the Solling area shows the history of vegetation and settlement over the last 7,800 years. In the early Atlantic period mixed deciduous forest with mainly Tilia together with Ulmus and Quercus grew in the area. In the late Atlantic period Quercus became most abundant. Fagus spread in the Sub-boreal period at about 2700 B.C. Since ca. 900 B.C. the Solling was covered by beech forests with some oak. In prehistoric times woodland grazing is indicated. Only in Medieval times are two settlements in the vicinity of the Ahlequellmoor reflected in the pollen diagram. The earlier one is dated to about A.D. 750–1020, and may be connected with the former Monastery of Hethis, which is thought to have existed close to the fen from A.D. 815 to 822. The second Medieval settlement dates to the 11th–12th century. The large-scale woodland destruction of late Medieval and modern times is not clearly visible. The silvicultural measures of the last 200 years are reflected by increasing values of spruce and grassland taxa.  相似文献   

17.
In the Lourdes Basin, pollen analytical results and 41 14C dates from three sites (four profiles, 538 spectra) have enabled a coherent biostratigraphy to be established from the last Pleniglacial to the present. The end of the Würm Pleniglacial is characterised by a long phase dominated by Poaceae that extended from ca. 20 000 to ca. 15 000 B.P. Another phase with Poaceae, in the context of a treeless environment, is recorded during the late-glacial between the Juniperus optimum (ca. 13 000 B.P.) and the Betula optimum (after ca. 12 500 B.P.). A marked decline in Betula and a rise in Artemisia values suggest a significant cooling of the climate during the Younger Dryas, an event which is now clearly recorded at several sites in southern Europe. The beginning of the Holocene is characterized by the minor role of Pinus and the early arrival of Quercus which achieves an absolute maximum before the arrival of Ulmus and Corylus. A critical assessment of previously published data is made in the light of these new results.  相似文献   

18.
19.
The mtDNA variation of 198 Aleuts, as well as North American and Asian populations drawn from the literature, were analyzed to reconstruct the Aleuts' genetic prehistory and to investigate their role in the peopling of the Circumarctic region. From median-joining network analysis, three star-like clusters were identified in the Aleuts within the following subhaplogroups: A3, A7 (an Aleut-specific subclade of A3), and D2. Mismatch analyses, neutrality test scores, and coalescent time estimates for these three components provided evidence of two expansion events, one occurring at approximately 19,900 B.P. and the other at 5,400 B.P. Based on these findings and evidence from the archaeological data, four general models for the genetic prehistory of the Aleutian Island chain are proposed: 1) biological continuity involving a kin-structured peopling of the archipelago; 2) intrusion and expansion of a non-native biface-producing population dominated by subhaplogroup D2; 3) amalgamation of Arctic Small Tool tradition peoples characterized by D2 with an older Anangula substratum; and 4) biological continuity with significant gene flow from neighboring populations of the Alaskan mainland and Kodiak Island. The Aleut mtDNAs are consistent with the Circumarctic pattern by the fixation of A3 and D2, and the exhibition of depressed diversity levels relative to Amerind and Siberian groups. The results of this study indicate a broad postglacial reexpansion of Na-Dene and Esko-Aleuts from reduced populations within northern North America, with D2 representing a later infusion of Siberian mtDNAs into the Beringian gene pool.  相似文献   

20.
The results of examining mtDNA variability in populations of chum salmon Oncorhynchus keta from the rivers of the basins of the seas of Japan and Okhotsk and in the chum salmon seasonal races of the Amur River are presented. A significant level of polymorphism between the majority of the populations studied was detected. The groups of chum salmon from the seas of Japan and Okhotsk displayed the most pronounced differences. Analysis of genetic variability demonstrated that periodic paleontologic and climatic changes in the past of this region were the most probable factor that caused the divergence of these populations. The advances and retreats of glaciers and the accompanying regressions and transgressions of the ocean level caused isolation of chum salmon in the refugia belonging hypothetically to the paleo-Shuifen and paleo-Amur regions. These population groups diverged presumably 350–450 thousand years ago. Differences between the seasonal races of the Amur chum salmon are insignificant, and their emergence dates back to the period of the last Wisconsinian glaciation. Probably, the main isolation factor now is the genetically determined time of spawning.  相似文献   

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