Maxillary first premolar angular differences between North American Indians and non-North American Indians

A quantitative technique for obtaining angular data on human maxillary first premolar teeth is presented. Measurement indicates that North American Indian buccal cusps are either buccolingually compressed mesially, or expanded distally, or both, when compared with non-Indian teeth. Surprisingly, data on Chinese and Eskimo samples are similar to non-Indian teeth rather than Indian teeth. Similar techniques may be applied to the more complex multicusped molar teeth in order to extract quantitative data from them.     

Lectotypifications of ten names of North American taxa in Clusiaceae, Elatinaceae, Ericaceae, Primulaceae, and Violaceae

Lectotypes are selected for 10 names inHypericum (Clusiaceae),Elatine (Elatinaceae),Arctostaphylos andVaccinium (Ericaceae),Androsace (Primulaceae), andViola (Violaceae).     

北美法医昆虫学年会及其论文简介

北美法医昆虫学第1,2届年会于2003年8月7～9日和2004年7月21～24日分别在美国内华达州拉斯维加斯和加利福尼亚州戴维斯召开,大会论文涉及到了案例分析、分类鉴定、教学、死后间隔时间推断和死亡原因查找等诸多方面。文章介绍了北美法医昆虫学年会,并对北美法医昆虫学第1,2届年会论文的相关内容进行总结分析。     

Acylated anthocyanins in flowers of Moricandia DC. (Brassicaceae)

New anthocyanin (MAA-3) in the flowers of Moricandia arvensis.

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Two new species of Sisymbrium (Brassicaceae) from coastal Peru

Two new species ofSisymbrium are described from the Department of Arequipa in south-western Peru. Both are annuals from the loma vegetation.Sisymbrium lactucoides has glabrous leaves with clasping bases and is very distinct.Sisymbrium ferreyrae is probably closest toS. llatasii, but it is a much smaller plant with petals and sepals of subequal length (vs. petals longer than sepals inS. llatasii).     

Lectotypifications and new combinations for Flora Nordica Vol. 1 (Lycopodiaceae–Papaveraceae)

Names of 34 taxa based on Nordic or Arctic material are lecto- or, in a few cases, neo-typified, published as new combinations or, discussed because of a change of basionym or other reasons.–Flora Nordica note No. 18.     

Mechanisms of synchrony in the North American fireflyPhotinus carolinus (Coleoptera: Lampyridae)

Photometric recordings combined with computer stimulation, acquisition and analysis were used to study synchrony in the North American fireflyPhotinus carolinus. A computer-generated burst of simulatedP. carolinus flashes was used to trigger a firefly flash burst. We found that the first triggered firefly flashes occurred after the second or third flashes in the stimulus burst, that there were fewer flashes in a triggered burst than a spontaneous burst, and that extending the stimulus flashes into the firefly's interburst interval inhibited firefly flashing. When the stimulus flash interval (389–560 ms) was changed, no change was seen in the interflash interval. When the stimulus flash interval was changed, the average time between stimulus flash and firefly flash (flash delay) changed as if the firefly interflash interval was constant. Thus, interflash interval inP. carolinus does not change its length, making it similar to the Southeast Asian synchronizerPteroptyx cribellata and different fromPteroptyx malaccae, which can change its interval. We suspect that the time between bursts is functionally analogous to the time between flashes in Southeast Asian synchronizers.     

Ancient North American Art Surfaces in the Art World: A Review of Hero, Hawk, and Open Hand

Hero, Hawk, and Open Hand rated as a must-see for anyone with an interest in art of the ancient Americas or ancient art in general—an exhibition whose breadth and depth in terms of visual material would be difficult, if not impossible, to replicate. This review takes a look beyond the immediate frame of the exhibition at some additional context related to the appreciation of these objects as ancient art, including some reflection on the original objectives of the exhibition and what appeared, at least to this anthropologist, as palpably missing or unspoken.     

Identification of single copy nuclear DNA markers for North American pit vipers

We describe 18 single copy nuclear DNA loci (10 loci cloned from a Sistrurus catenatus catenatus genomic library and eight intron-based loci amplified using conserved primers) that detect sequence variation in species from all genera (Sistrurus, Agkistrodon and Crotalus) of North American pit viper snakes. These loci (mean size in bp ± SE: 433 ± 51) show large numbers of phylogenetically informative sites across species (mean + SE: 10.2 ± 1.5), but limited variation within subspecies suggesting that they will be most useful for multilocus species-level phylogenetic analyses in these snakes.     

Chirognathia dracula gen. et spec. nov. (Gnathostomulida) from the west coast of North America

A new gnathostomulid genus and species, Chirognathia dracula gen. et spec. nov., is described from intertidal surf grass (Phyllospadix) rhizomes on high-energy coasts of Vancouver Island (Canada) and Bodega Bay (California). The characteristics of the reproductive system place the new genus in Bursovaginoidea-Scleroperalia and features of the mouth parts (except for the absence of a jugum) assign it to the family Gnathostomulidae. Chirognathia nov. gen. is characterized by a delicate, transverse shield-shaped basal plate and by jaws with three tooth rows, of which the median appears as a bundle.     

Revisiting projected shifts in the climate envelopes of North American trees using updated general circulation models

Global climate models are constantly being upgraded, but it is often not clear what these changes have on climate change impact projections. We used difference maps to directly compare downscaled projections of temperature and precipitation across North America for two versions (or generations) of three different Atmospheric‐Ocean General Circulation Models (AOGCM)s. We found that AOGCM versions differed in their projections for the end of the current century by up to 4 °C for annual mean temperature and 60% for annual precipitation. To place these changes in an ecological context, we reanalyzed our work on shifts in tree climate envelopes (CEs) using the newer‐generation AOGCM projections. Based on the updated AOGCMs, by the 2071–2100 period, tree CEs shifted up to 2.4 degrees further north or 2.6 degrees further south (depending on the AOGCM) and were about 10% larger in size. Despite considerable differences between versions of a given AOGCM, projections made by the newer version of each AOGCM were in general agreement, suggesting convergence across the three models studied here. Assessing the AOGCM outputs in this way provides insight into the magnitude and importance of change associated with AOGCM upgrades as they continue to evolve through time.     

狭义小奥德蘑属(膨瑚菌科,蘑菇目)的一个新系统

本文对狭义小奥德蘑属Oudemansiella s. str.的概念做了修订,在修订后的属中,狭义干蘑属Xerula s. str.的物种不纳入其中。在狭义小奥德蘑属下,提出了一个包含4个组O. sect. Oudemansiella、Mucidula、Dactylosporina 和 Radicatae的新系统。小奥德蘑组sect. Oudemansiella包括热带至南温带的一些物种,如新热带小奥德蘑O. platensis、澳洲小奥德蘑O. australis、旧热带小奥德蘑O. canarii和宽褶小奥德蘑O. crassifolia,这些物种的菌盖表皮为粘栅栏型,由菌丝组成,但其中常夹杂有链状排列的膨大细胞。粘蘑组sect. Mucidula包含北半球温带至亚热带的一些物种,如粘小奥德蘑O. mucida、网褶小奥德蘑O. venosolamellata和近粘小奥德蘑O. submucida,其菌盖表皮为粘子实层-栅栏型,由近棒状的顶端膨大细胞组成。小奥德蘑组和粘蘑组的物种,在外形和小生境上有相似之处,其担子果皆生于地表外的腐木上,菌柄上有或无菌环。刺孢组sect. Dactylosporina包含中南美洲那些孢子表面有指状凸起的物种。长根组sect. Radicatae由长根小奥德蘑O. radicata及其近缘种为代表,是该属中最大的组,包括该属其他三组之外的所有种。北美的O. americana、欧洲的O. caussei 和东亚的O. hongoi曾被置于小奥德蘑属中的白毛组O. sect. Albotomentosae或干蘑属的亮毛组X. sect. Hyalosetae,在本系统中它们没有纳入小奥德蘑属,因为它们可能代表一个单独的属。本文还提出了1新等级、32个新组合和1个新名称。     

Population density of North American elk: effects on plant diversity

Large, herbivorous mammals have profound effects on ecosystem structure and function and often act as keystone species in ecosystems they inhabit. Density-dependent processes associated with population structure of large mammals may interact with ecosystem functioning to increase or decrease biodiversity, depending on the relationship of herbivore populations relative to the carrying capacity (K) of the ecosystem. We tested for indirect effects of population density of large herbivores on plant species richness and diversity in a montane ecosystem, where increased net aboveground primary productivity (NAPP) in response to low levels of herbivory has been reported. We documented a positive, linear relationship between plant-species diversity and richness with NAPP. Structural equation modeling revealed significant indirect relationships between population density of herbivores, NAPP, and species diversity. We observed an indirect effect of density-dependent processes in large, herbivorous mammals and species diversity of plants through changes in NAPP in this montane ecosystem. Changes in species diversity of plants in response to herbivory may be more indirect in ecosystems with long histories of herbivory. Those subtle or indirect effects of herbivory may have strong effects on ecosystem functioning, but may be overlooked in plant communities that are relatively resilient to herbivory.     

12种十字花科植物花粉形态研究

采用扫描电子显微镜对十字花科8属12种植物的花粉形态特征进行了观察分析.其中8种为首次报道.观察结果表明:4族8属12种十字花科植物花粉形态的一般特征为:花粉粒长球形至超长球形;极面观三裂圆形,少数四裂圆形;外壁纹饰为网状或细网状纹饰;三沟,偶四沟.12种植物的花粉可划分为5种类型:(1)花粉粒长球形,网状纹饰,三沟;(2)花粉粒超长球形,网状纹饰,三沟;(3)花粉粒长球形,细网状纹饰,三沟;(4)花粉粒超长球形,细网状纹饰,三沟;(5)花粉粒长球形,三或四沟,网状纹饰.十字花科花粉形态特征在不同族间、不同属间以及同属不同种间均没有明显规律,在十字花科分类过程中,不宜单独以花粉形态特征作为依据.     

Neutral Evolution of Synonymous Base Composition in the Brassicaceae

The GC content of synonymous sites is elevated in genes from both Brassica oleraceae and Arabidopsis lyrata compared with Arabidopsis thaliana. However, this shift in base composition is independent of gene expression level, and there is no evidence for a similar difference in the frequency of codons preferred by translational selection. The results suggest that composition evolution is caused by a change in mutation bias or biased gene conversion, rather than by a reduction in the efficacy of natural selection in selfing Arabidopsis. [Reviewing Editor: Dr. Magrus Nordborg]     

Brassicaceae: Species checklist and database on CD-Rom

A species checklist has been prepared for the Brassicaceae (Cruciferae) family, providing the first updated list in over 70 years. The family, currently, includes 338 genera and 3709 species. The database contains approximately 14,000 taxonomic names (records). Taxon status and synonymy, taxon name, scientific authority, literature source and source verification, and the basionym are provided for each record. Electronic supplementary material to this article is available at and is accessible for authorized users.     

Multiple hybrid formation in natural populations: concerted evolution of the internal transcribed spacer of nuclear ribosomal DNA (ITS) in North American Arabis divaricarpa (Brassicaceae)

DNA sequence variation of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA from Arabis holboellii, A. drummondii, and its putative hybrid A. divaricarpa was analyzed to study hybrid speciation in a species system geographically covering nearly the entire North American continent. Based on molecular systematics the investigated species are better combined under the genus Boechera. Multiple intraindividual ITS copies were detected in numerous accessions of A. divaricarpa, and, to a minor extent, in the parental taxa. Comparative phylogenetic analysis demonstrates that reticulate evolution is common. Consequently, concerted evolution of ITS regions resulted in different types of ITS fragments not only in hybrid populations but also in one of the parental taxa, A. holboellii. Hybrid formation often occurred independently at different sites and at different times, which is reflected by ITS copies resampling the original parental sequence variation in different ways. Some biogeographic structuring of genetic diversity is apparent and mirrors postglacial migration routes. Hybridization, reticulation, and apomixis are assumed to be the major forces driving speciation processes in this species complex. Analysis of conserved regions and secondary structures of the ITS region provided no evidence that, in this system, hybrid ITS evolution is predominantly driven in a particular direction. However, two regions in the ITS1 and ITS2, respectively, show higher mutation rates than expected from outgroup comparisons. Strong evidence for the occurrence of apomixis in A. holboellii and A. divaricarpa has come from pollen size measurements and estimations of pollen quality, which favor the hypothesis that A. drummondii served as paternal hybridization partner more frequently than A. holboellii.