Mitochondrial phylogeography and population history of pine martens Martes martes compared with polecats Mustela putorius

The flora and fauna of Europe are linked by a common biogeographic history, most recently the Pleistocene glaciations that restricted the range of most species to southern refugial populations. Changes in population size and migration, as well as selection, have all left a signature on the genetic differentiation. Thus, three paradigms of postglacial recolonization have been described, inferred from the patterns of DNA differentiation. Yet some species, especially wide-ranging carnivores, exhibit little population structuring between the proposed refugia, although relatively few have been studied due to the difficulty of obtaining samples. Therefore, we investigated mitochondrial variation in pine martens, Martes martes, in order to understand the extent to which they were affected by glacial cycles, and compared the results with an analysis of sequences from polecats, Mustela putorius. A general lack of ancient lineages, and a mismatch distribution that is consistent with an expanding population, is evidence that the present-day M. martes and Mu. putorius in central and northern Europe colonized from a single European refugium following a recent glaciation. There has also been interspecific mitochondrial introgression between M. martes and the sable M. zibellina in Fennoscandia.     

山东莒南发现的石制品

本文报道的128件人工石制品分别采自山东莒南县的石莲子乡烟敦岭和扁山乡九顶莲花山两个地点。石制品常见类型有边刮器,端刮器和砍斫器等,另有少量的雕刻器和尖状器,内含典型细石器。就石制品的组合及工艺水平而言,其时代可能属于旧石器时代末期。     

Lithic microwear analysis in archeology

Stone tools are the most durable and ubiquitous residue of prehistoric hominid activity. For this reason, archeologists attempt to learn as much as possible about hominid behavior from the analysis of lithic artifacts. Lithic microwear analysis reconstructs aspects of stone-tool use from patterned variation in the traces of microscopic wear on those tools. The analysis of lithic microwear traces has increased our understanding of how stone tools were used in contexts ranging from the early Pleistocene to the ethnographic present.     

A link between maze learning and hippocampal expression of neuroleukin and its receptor gp78

Neuroleukin (NLK) is a multifunctional protein involved in neuronal growth and survival, cell motility and differentiation, and glucose metabolism. We report herein that hippocampal expression of NLK and its receptor gp78 is associated with maze learning in rats. First, mRNA levels of NLK and gp78 were significantly increased in hippocampi of male Fischer-344 rats following training in the Stone T-maze and the Morris water maze. Second, a parallel increase was found in hippocampal NLK and gp78 proteins after maze learning. Third, NLK and gp78 mRNA and protein expression in hippocampus was reduced in a group of aged rats that showed more errors during the acquisition of the Stone maze task as compared with young rats. Finally, application of recombinant NLK to hippocampal neurons significantly enhanced glutamate-induced ion currents, functional molecular changes that have been correlated with learning in vivo. Taken together, our results identify a novel association of hippocampal expression of NLK and its receptor gp78 with rat maze learning. Interaction of NLK with gp78 and subsequent signaling may strengthen synaptic mechanisms underlying learning and memory formation.     

Human remains from Blombos Cave, South Africa: (1997-1998 excavations)

The Middle Stone Age (MSA) layers at Blombos Cave contain abundant bifacial Still Bay points, formal and ad hoc bone artefacts, and an intentionally incised bone piece. These artefacts add weight to arguments that some aspects of modern human behavior developed earlier in sub-Saharan Africa than elsewhere. Four human teeth were recovered from the MSA strata at Blombos during the 1997-1998 excavations. Two are heavily worn deciduous teeth, and two are incomplete permanent premolar crowns. The Blombos di(1)is comparatively large in relation to modern African homologues, falling within the lower part of the observed Neandertal range. The dm(1)and P(3)are comparable to modern teeth and smaller than most Neandertal crowns. The premolars preserve horizontal circum-cervical striae that suggest palliative toothpick use. The di(1)evinces labial scratches that resemble neither the "cutmarks" that have been observed on Neandertal incisors, nor the striae that have been recorded on modern human teeth.     

Avian top predator and the landscape of fear: responses of mammalian mesopredators to risk imposed by the golden eagle

Top predators may induce extensive cascading effects on lower trophic levels, for example, through intraguild predation (IGP). The impacts of both mammalian and avian top predators on species of the same class have been extensively studied, but the effects of the latter upon mammalian mesopredators are not yet as well known. We examined the impact of the predation risk imposed by a large avian predator, the golden eagle (Aquila chrysaetos, L.), on its potential mammalian mesopredator prey, the red fox (Vulpes vulpes, L.), and the pine marten (Martes martes, L.). The study combined 23 years of countrywide data from nesting records of eagles and wildlife track counts of mesopredators in Finland, northern Europe. The predation risk of the golden eagle was modeled as a function of territory density, density of fledglings produced, and distance to nearest active eagle territory, with the expectation that a high predation risk would reduce the abundances of smaller sized pine martens in particular. Red foxes appeared not to suffer from eagle predation, being in fact most numerous close to eagle nests and in areas with more eagle territories. This is likely due to similar prey preferences of the two predators and the larger size of foxes enabling them to escape eagle predation risk. Somewhat contrary to our prediction, the abundance of pine martens increased from low to intermediate territory density and at close proximity to eagle nests, possibly because of similar habitat preferences of martens and eagles. We found a slightly decreasing trend of marten abundance at high territory density, which could indicate that the response in marten populations is dependent on eagle density. However, more research is needed to better establish whether mesopredators are intimidated or predated by golden eagles, and whether such effects could in turn cascade to lower trophic levels, benefitting herbivorous species.     

基于花粉形态数量分类的核果类系统关系研究

运用扫描电子显微镜(SEM)观察了李属、杏属、樱桃属和桃属的花粉形态,观察结果表明:核果类果树的花粉均为近扁球形,等极,辐射对称,极面观为三角形或钝三角形,赤面观均为椭圆形,花粉粒大小在各属间差异明显。核果类果树花粉属N3P4C5类型,3条孔沟沿极轴方向在赤道面上等间距环状分布,内孔位于沟的中央,完全独立于外壁,孔盖覆不规则的拟网状或脑纹状纹饰。供试核果类果树花粉的表面纹饰由平行条纹或不规则条脊及散落于条脊间的穿孔组成,各属间条脊的排列方式、宽窄、脊洼深浅及穿孔有无等性状上存在明显差异。根据花粉大小、表面纹饰及覆盖层穿孔等的一般演化规律,推测核果类果树由低到高的演化顺序为李属→杏属→樱桃属→桃属,并在聚类分析的基础上对属间亲缘关系进行了探讨,旨在为核果类系统关系的研究提供孢粉证据。     

Stone artifacts and hominins in island Southeast Asia: new insights from Flores, eastern Indonesia

This study reexamines the current understanding of Pleistocene stone-artifact assemblages in island Southeast Asia. A differentiation has long been made between assemblages of large-sized "core tools" and assemblages of small-sized "flake tools." "Core tool" assemblages are often argued to be the handiwork of early hominin species such as Homo erectus, while small-sized "flake tool" assemblages have been attributed to Homo sapiens. We argue that this traditional Southeast Asian perspective on stone tools assumes that the artifacts recovered from a site reflect a complete technological sequence. Our analyses of Pleistocene-age artifact assemblages from Flores, Indonesia, demonstrate that large pebble-based cores and small flake-based cores are aspects of one reduction sequence. We propose that the Flores pattern applies across island Southeast Asia: large-sized "core tool" assemblages are in fact a missing element of the small-sized flake-based reduction sequences found in many Pleistocene caves and rock-shelters. We conclude by discussing the implications of this for associating stone-artifact assemblages with hominin species in island Southeast Asia.     

Announcing a Still Bay industry at Sibudu Cave, South Africa

Sibudu Cave in KwaZulu-Natal, South Africa, has a long Middle Stone Age (MSA) sequence with good organic preservation. The uppermost MSA sequence includes industries attributed to the final and late MSA and the Howiesons Poort. Below the Howiesons Poort are two layers containing some thin, bifacial lanceolate points, mostly in the form of distal and proximal fragments. These double-pointed foliates are the fossile directeur of the Still Bay Industry, and importantly, this Sibudu industry provides confirmation that the Still Bay predates the Howiesons Poort Industry. Technologically, the points from Sibudu are comparable to those from other South African sites with Still Bay occurrences (e.g., Blombos Cave and Hollow Rock Shelter). Although dating of the Sibudu Still Bay is preliminary, its age falls within the range of that at Blombos. For the past two decades, archaeologists have rejected the idea of a Still Bay Industry occurring outside of the Western Cape, but the Still Bay at Sibudu shows that this industry was, indeed, geographically widespread.     

Fur snagging as a method of evaluating the presence and abundance of a small carnivore, the pine marten (Martes martes)

The pine marten Martes martes was once considered one of Ireland's rarest carnivores, but is now recolonizing many of the areas where it was once extirpated. It is important to monitor its population expansion so that conservation management decisions can be made regarding the status of this species. In this study, we investigate the use of fur snagging devices as a method of estimating pine marten presence and abundance in lowland and upland broadleaf woodland. We investigated whether these devices reliably detected presence, and how quickly. It was found that hair traps functioned very well in detecting pine martens on all survey transects and was essential in their detection in the most isolated site. A survey length of 6 days was sufficient to detect pine marten in all survey sites, with most detections occurring within the first 4 days. The hair traps functioned equally well as scat location for detecting pine marten and had the added advantage of there being no confusion as to the origin of the sample. Live trapping was used to verify the estimates of relative abundance from hair traps. There was a trend for the number of hair samples per site and the number of times animals were trapped per site to be positively correlated, although this was not significant. Hair traps do provide a real alternative for the monitoring of pine martens in both lowland and upland broadleaf woodlands, overcoming many of the disadvantages associated with scat location.