The southern king crab Lithodes santolla is one of the most economically important fishery species in the southern waters of the Atlantic and Pacific Oceans. A combination of stomach content and ...stable isotope analyses was used to reveal the potential dietary characteristics, isotopic niche, overlap among maturity stages and sexes, and trophic relationships of an L. santolla population in the Nassau Bay, Cape Horn region. Stable isotope analyses indicated that L. santolla assimilated energy from a basal carbon source, the giant kelp Macrocystis pyrifera, forming the trophic baseline of the benthic food web. Moreover, the trophic position of L. santolla varied among late juveniles and adults, suggesting that the southern king crab does undergo an ontogenetic diet shift. L. santolla exhibited intraspecific isotopic niche variation, reflecting niche differentiation which allows the species to partition resources. The trophic relationships of L. santolla with the associated fauna suggested some potential interactions for food resources/habitat use when they are limited. This study is the first attempt to characterize the trophic dynamics of the southern king crab in the Cape Horn area and, by generating more data, contributes to the conservation of the king crab population and the long-term management of local fisheries that rely on this resource.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The rich fossil record of the family Equidae (Mammalia: Perissodactyla) over the past 55 MY has made it an icon for the patterns and processes of macroevolution. Despite this, many aspects of equid ...phylogenetic relationships and taxonomy remain unresolved. Recent genetic analyses of extinct equids have revealed unexpected evolutionary patterns and a need for major revisions at the generic, subgeneric, and species levels. To investigate this issue we examine 35 ancient equid specimens from four geographic regions (South America, Europe, Southwest Asia, and South Africa), of which 22 delivered 87-688 bp of reproducible aDNA mitochondrial sequence. Phylogenetic analyses support a major revision of the recent evolutionary history of equids and reveal two new species, a South American hippidion and a descendant of a basal lineage potentially related to Middle Pleistocene equids. Sequences from specimens assigned to the giant extinct Cape zebra, Equus capensis, formed a separate clade within the modern plain zebra species, a phenotypicically plastic group that also included the extinct quagga. In addition, we revise the currently recognized extinction times for two hemione-related equid groups. However, it is apparent that the current dataset cannot solve all of the taxonomic and phylogenetic questions relevant to the evolution of EQUUS: In light of these findings, we propose a rapid DNA barcoding approach to evaluate the taxonomic status of the many Late Pleistocene fossil Equidae species that have been described from purely morphological analyses.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
La restauración patrimonial de monumentos históricos presenta particulares desafíos de implementación. En este escenario el trabajo arqueológico es parte fundamental de aquel proceso constructivo, ...legal, de conservación y comunitario. Presentamos los resultados de la documentación y excavaciones arqueológicas realizadas bajo el piso de la centenaria Iglesia de San Juan (Dalcahue, Chiloé) y del sitio arqueológico San Juan 1, en el archipiélago patagónico occidental. Las inhumaciones históricas (ca. 280 a 140 años cal AP) y los diversos materiales arqueológicos recuperados desde matrices sedimentarias formadas por una sucesión de ocupaciones por parte de cazadores recolectores marinos (desde ca. 6.000 AP), constituyen un conjunto de información que nutre la secuencia cultural del área. Así, los análisis bioantropológicos, cerámicos, líticos, arqueofaunísticos e históricos realizados nos informan sobre la subsistencia de los grupos humanos y parte de los conjuntos tecnológicos utilizados y descartados tanto en tiempos prehispánicos como históricos en la isla de Chiloé. Se espera que la implementación de este trabajo contribuya con estrategias futuras de restauración y puesta en valor que respeten los usos históricos y contemporáneos de diversas localidades patrimoniales.
Mechanisms that reliably and efficiently guide practitioners to find relevant evidence are urgent for conservation decision‐making in Chilean Patagonia. The objective of this study was to ...systematically collect, characterize, and synthesize the extensive evidence about conservation knowledge in Chilean Patagonia focusing on the impacts of global change drivers on ecosystems and human–nature relationships, identifying knowledge gaps, and providing policy recommendations. The quality of the evidence was assessed through a predefined level‐of‐evidence hierarchy scale, applied to a sample of the studies reviewed. We compiled ~1000 studies documenting that evidence focusing on terrestrial and marine ecosystems has grown exponentially. For terrestrial ecosystems, most studies have addressed climate change, habitat change, and invasive species; while for marine ecosystems, studies have focused on pollution, invasive species, and habitat change. We identified that an important gap is the study of the social dimensions of conservation, and future efforts should focus on incorporating traditional and local knowledge as this can help point the way to ecosystem conservation. The appraisal of the quality of the evidence showed that ~80% of the sample represented reliable evidence with underlying data and an experimental design. Enhanced efforts to deliver this evidence to decision‐makers in a user‐friendly format for evidence uptake in conservation policy are urgent. In this review, we provide a tool that can help practitioners to find evidence reliably to improve decision‐making for the conservation of ecosystems in Chilean Patagonia.
Mechanisms that guide practitioners to find the evidence reliably and efficiently are urgent for conservation decision making in Chilean Patagonia that has more than half of its territory remaining and protected. The evidence about conservation knowledge was systematically characterized and synthesized in Chilean Patagonia, identifying knowledge gaps and providing policy recommendations.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
A new Late glacial-Holocene palaeoenvironmental record from near Lago Lynch (53°54′S, 69°26′W), Tierra del Fuego is presented. The record was sampled from a mire located within the deciduous ...Nothofagus forest-steppe ecotone and pollen and spore analysis suggest a high degree of vulnerability of past vegetation to changes in effective moisture. AMS radiocarbon dating supplemented by the application of tephrochronology including the geochemical fingerprinting of six visible and cryptotephra layers provides robust age constraint. The Lago Lynch record commences at c.15.6 ka. The sequence of vegetation changes between c.15.6 and 14.4 ka reflect a gradual increase in temperature and humidity followed by a colder interval between c.14.4 and 13.3 ka, which is broadly coeval with the Antarctic Cold Reversal. After c.13.3 ka patches of Nothofagus forest appeared, suggesting more mesic-temperate conditions leading gradually to the establishment of an open-canopy Nothofagus forest by c.12.5 ka which marks the start of the Holocene. Moderate to strong effective moisture levels dominated during the early Holocene until c.11.0 ka, followed by a sustained period (c.11.0–6.5 ka) of drier climatic conditions, particularly two arid phases at c.10.5–10.0 ka and 8.5–6.5 ka. An eastwards expansion of the forest margin after c.6.5 ka at the site suggests a return to more humid conditions during the late Holocene. We argue that the periods of increased moisture and aridity inferred from Lago Lynch closely reflect the extent to which the southern westerly winds (SWWs) push eastwards to the drier regions of Fuego-Patagonia during the Holocene. The longitudinal variations in moisture are driven by the nature and timing of latitudinal shifts in the SWWs. More significantly the vulnerability of the forest-steppe ecotone to moisture changes amplifies the ecological impact of relatively small-scale shifts in the SWWs.
•Late glacial-Holocene palaeoenvironmental record from central Tierra del Fuego.•The early spread of Nothofagus forest during the ACR constrained by humidity.•Forest-steppe ecotone vulnerable to shifts in the southern westerly winds.•Intense arid phases during the Holocene at c.10.5–10.0 ka and c.8.5–6.5 ka•Identification of cryptotephras extend the application of tephrochronology.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
7.
Early human dispersals within the Americas Moreno-Mayar, J Víctor; Vinner, Lasse; de Barros Damgaard, Peter ...
Science (American Association for the Advancement of Science),
12/2018, Volume:
362, Issue:
6419
Journal Article
Peer reviewed
Open access
Studies of the peopling of the Americas have focused on the timing and number of initial migrations. Less attention has been paid to the subsequent spread of people within the Americas. We sequenced ...15 ancient human genomes spanning from Alaska to Patagonia; six are ≥10,000 years old (up to ~18× coverage). All are most closely related to Native Americans, including those from an Ancient Beringian individual and two morphologically distinct "Paleoamericans." We found evidence of rapid dispersal and early diversification that included previously unknown groups as people moved south. This resulted in multiple independent, geographically uneven migrations, including one that provides clues of a Late Pleistocene Australasian genetic signal, as well as a later Mesoamerican-related expansion. These led to complex and dynamic population histories from North to South America.
This paper focuses on the late Holocene occupation of hunter‐gatherers at the Marazzi 2 site located on the northwestern steppe of Tierra del Fuego, Chile. Our aim is to understand stratigraphy, ...formation processes, and pedogenesis with respect to human occupation over the last 3000 years. Based on archaeological excavations on a fluvial terrace of the Torcido River, we integrate soil micromorphology, mineralogy, geochemistry, magnetic susceptibility, and geomorphology, as well as the micro‐ and macrofrequency distributions of archaeological material. A micro‐taphonomical perspective is also applied to anthropogenic components recorded in sedimentary thin sections. We discuss various events in the interplay between soil development and human occupation through time. Marazzi 2 was witness to aggradation and pedogenesis with an episode of surface stability coincident with a phase of more intense human occupation at about 860 BC. Taphonomic analysis suggests that there are multiple occupation events mixed together, probably by biomechanical processes, resulting in a palimpsest with poor temporal resolution.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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