Ecological and evolutionary consequences of selective interspecific information use

Recent work has shown that animals frequently use social information from individuals of their own species as well as from other species; however, the ecological and evolutionary consequences of this social information use remain poorly understood. Additionally, information users may be selective in their social information use, deciding from whom and how to use information, but this has been overlooked in an interspecific context. In particular, the intentional decision to reject a behaviour observed via social information has received less attention, although recent work has indicated its presence in various taxa. Based on existing literature, we explore in which circumstances selective interspecific information use may lead to different ecological and coevolutionary outcomes between two species, such as explaining observed co-occurrences of putative competitors. The initial ecological differences and the balance between the costs of competition and the benefits of social information use potentially determine whether selection may lead to trait divergence, convergence or coevolutionary arms race between two species. We propose that selective social information use, including adoption and rejection of behaviours, may have far-reaching fitness consequences, potentially leading to community-level eco-evolutionary outcomes. We argue that these consequences of selective interspecific information use may be much more widespread than has thus far been considered.     

Ethnicity and class identity: The case of French‐ and English‐speaking Canadians*

This study addresses the racial and religious contexts of identity formation among Lebanese immigrants to the United States of America and Somali immigrants to Canada. Each enters with a different racial status: Lebanese as white; Somalis as black/visible minority. Ethnographic interviews explore the strategies of adaptation and identity development within these groups. Specifically, we compare and contrast the Lebanese and Somali experience through an analysis of ethnic relations in the country of origin, the conditions of immigration, and through accounts of their encounters and identity negotiation with the host society. We demonstrate the strategies each group implements to negotiate both race and religion in identity development. Our findings reveal that each group attempts to make their religious identity evident, however, Somali immigrants must negotiate the effects of ‘othering’ processes with both race and religion, while Lebanese immigrants build a religious identity from privileges afforded to them by virtue of their white racial status.     

基于多基因序列分析对尖孢镰孢菌古巴专化型（香蕉枯萎病菌）生理小种的鉴定

由尖孢镰孢菌古巴专化型Fusarium oxysporum f. sp. cubense, Foc引起的香蕉枯萎病是香蕉生产上的毁灭性病害,自1996年以来已对我国华南地区香蕉生产造成了严重危害。传统上香蕉枯萎病菌生理小种的鉴定主要采用人工接种鉴别寄主尔后测定病菌致病性的方法,但实验周期长,且受季节影响。以来自澳大利亚的香蕉枯萎病菌生理小种1号（BW1）、2号（Race 2）、3号（Race 3）以及亚热带4号（BW4）为对照,对分离自我国华南地区主要香蕉产区（广东、广西、海南、福建等省区）的14株香蕉枯萎病菌的单孢菌株进行致病性测定,并结合热带4号小种（TR4）和亚热带4号小种（ST4）的分子特异检测方法,确定其生理小种类型;同时,利用ITS、TEF-1α、IGS、histone H3、β-tubulin等 5个主要用于镰孢菌系统发育学研究的基因,研究不同地区不同来源的Foc菌株之间的亲缘关系及其与非病原尖孢镰孢菌的关系,并评价这5个基因在香蕉枯萎病菌生理小种鉴定上的应用价值。研究结果表明：（1）来源于我国华南地区的4号小种主要为热带4号小种;（2）TEF-1α、IGS、histone H3等3个基因片段能够将Foc中不同生理小种的菌株划分成不同的系统发育谱系,与致病性测定的结果具有对应关系,也能较好地反映尖孢镰孢菌种内菌株的亲缘关系,可用于香蕉枯萎病菌生理小种鉴定;（3）我国Foc 1号生理小种的遗传多样性高于4号生理小种,Foc 1号生理小种的菌系与来自香蕉果实上的非病原尖孢镰孢菌的亲缘关系比其与Foc 4号生理小种的菌系的亲缘关系更近。     

Sensitivity of the invasive geophyte Oxalis pes-caprae to nutrient availability and competition

BACKGROUND AND AIMS: Invasion by alien plants may be partially related to disturbance-related increases in nutrient availability and decreases of competition with native species, and to superior competitive ability of the invader. Oxalis pes-caprae is an invasive winter geophyte in the Mediterranean Islands that reproduces vegetatively via bulbs. An investigation was made into the relative responses of O. pes-caprae and the native annual grass Lolium rigidum to nutrient availability and to competition with each other in order to understand patterns of invasion in the field. Because Oxalis accumulates oxalic acid in its leaves, which could ameliorate soil phosphorous availability, field observations were made to determine whether the presence of Oxalis alters soil P availability. METHODS: A full-factorial glasshouse experiment was conducted with nutrient availability (high and low) and competition (Lolium alone, Oxalis alone, and Lolium and Oxalis together). Plant performance was assessed by determining (1) above- and below-ground biomass at the time of Oxalis maximum biomass and (2) reproductive output of Oxalis and Lolium at the end of their respective growth cycles. Measurements were also taken for leaf N and P content. Soil samples were taken in the field from paired Oxalis-invaded and non-invaded plots located in Menorca (Balearic Islands) and available P was determined. KEY RESULTS: High nutrient availability increased Oxalis and Lolium vegetative biomass and reproductive output to a similar degree. Competition with Lolium had a much stronger negative effect on Oxalis bulb production than reduced nutrients. Lolium was a superior competitor than Oxalis; the latter did not affect Lolium maximum biomass and spike production. Significantly greater soil-P availability in Oxalis-invaded field soils relative to paired non-invaded soils suggest that Oxalis influences soil P cycling. CONCLUSIONS: Oxalis is a poor competitor. This is consistent with the preferential distribution of Oxalis in disturbed areas such as ruderal habitats, and might explain its low influence on the cover of native species in invaded sites. The results also suggest that certain disturbances (e.g. autumn ploughing) may greatly enhance Oxalis invasion.     

Chemical races in the red alga Laurencia nipponica (Rhodomelaceae, Ceramiales)

Genetic variation in the synthesis of halogenated secondary metabolites in the Japanese marine red alga Laurencia nipponica Yamada (Rhodomelaceae, Ceramiales) has been investigated in laboratory crossing experiments and chemical analyses, F₁ tetrasporophytes and F₁ gametophytes resulting from crosses within chemical races produced major metabolites characteristic of these races. F₁ tetrasporophytes derived from reciprocal interracial crosses produced: (i) both parental types of secondary metabolites; (ii) either of the parental types; or (iii) a further major compound in addition to both parental types or in addition to either of the parental types. The latter cases suggest that hybrid-specific products were formed by the combined enzymatic complements of the parents, as F₁ gametophytes derived from these interracial F₁ tetrasporophytes yielded one or other of their parental products in an approximate 1:1 ratio. The population structure was analyzed at localities in Hokkaido, where two of the chemical races occur sympatrically. At Usujiri (Minami-kayabe), where the prepacifenol race and the laureatin race were sym-patric, hybrid gametophytes (recombination type) were found in high frequency in addition to hybrid tetra sporophytes, which strongly suggests that a new, pre-pacifenol/laureatm race is beginning to be produced by natural hybridization and recombination. By contrast, at Oshoro Bay, where the laurencin race and the epi-lauraliene race grew together, the interracial hybrids were rare: only a few tetrasporophytes (probably F₁ generation) were found, suggesting that racial integrity may be retained by habitat segregation and/or the absence of recombination-type gametophytes.     

Uncloaking a Lost Cause: Decolonizing ancestry estimation in the United States

Since the professionalization of US-based forensic anthropology in the 1970s, ancestry estimation has been included as a standard part of the biological profile, because practitioners have assumed it necessary to achieve identifications in medicolegal contexts. Simultaneously, forensic anthropologists have not fully considered the racist context of the criminal justice system in the United States related to the treatment of Black, Indigenous, and People of Color; nor have we considered that ancestry estimation might actually hinder identification efforts because of entrenched racial biases. Despite ongoing criticisms from mainstream biological anthropology that ancestry estimation perpetuates race science, forensic anthropologists have continued the practice. Recent years have seen the prolific development of retooled typological approaches with 21st century statistical prowess to include methods for estimating ancestry from cranial morphoscopic traits, despite no evidence that these traits reflect microevolutionary processes or are suitable genetic proxies for population structure; and such approaches have failed to critically evaluate the societal consequences for perpetuating the biological race concept. Around the country, these methods are enculturated in every aspect of the discipline ranging from university classrooms, to the board-certification examination marking the culmination of training, to standard operating procedures adopted by forensic anthropology laboratories. Here, we use critical race theory to interrogate the approaches utilized to estimate ancestry to include a critique of the continued use of morphoscopic traits, and we assert that the practice of ancestry estimation contributes to white supremacy. Based on the lack of scientific support that these traits reflect evolutionary history, and the inability to disentangle skeletal-based ancestry estimates from supporting the biological validity of race, we urge all forensic anthropologists to abolish the practice of ancestry estimation.     

Study of resistance components of some promising wheat lines to yellow rust disease in the seedling stage

The most reliable method to control the wheat yellow rust disease is cultivation of resistance cultivars. To provide resistance, it is necessary to be aware of the amount and the quality of pathogenesis of disease factors and resistant specifications. In this study, 82 wheat promising lines with Bolani susceptible cultivar in randomised complete block design were tested in the seedling stage. This experiment was carried out in greenhouse condition, and it was assessed by two races: 166E254A+Yr27+ and 6E150A+, which were more and less pathogenic, respectively. The attributes of resistance were measured for infection type (IT), latent period (LP), pustule size (PS) and density. Results of variance analysis relating two races between wheat genotypes for these four attributes of resistance showed that there is a difference in the probability at 1% level. The statistical analyses for these components of resistance indicated that there is negative and high solidarity between IT and LP, and also among the number and density of pustules. The correlation between IT and LP and both races were -0.90 and -0.98, respectively. Cluster analysis of lines to each race was classified as resistant, semi-resistant and susceptible. The first group of the resistant lines were 27 lines in which their ITs of 0–2, mean LP of 18?days PS of 2.8 and pustule density of 1.1 were recorded.     

Races of Xanthomonas citri subsp. malvacearum,the causal organism of bacterial blight of cotton in northern Nigeria

Xanthomonas citri subsp. malvacearum (Xcm) causes severe qualitative and quantitative losses to farmers in cotton-growing areas of the world. Isolates of Xcm were extracted from cotton seeds obtained from five ginneries located in Funtua, Malumfashi, Gusau and Zaria and standardised to 10^?5?cfu/ml. One isolate per location was used to inoculate three sets of 10 cotton differential lines known to differentiate races of Xcm through possession of B-genes for resistance to bacterial blight. Each cotton differential line was inoculated with the isolates at the six-leaf stage and SDW was inoculated as control. One hundred and sixty pots used were arranged in completely randomised design on the screen house bench. Four different pathogenic races were identified namely race 1, race 12, race 13 and race 16. This confirms the existence of an evolution of the species across northern Nigeria.     

‘A genealogist's paradise’: France,Québec and the genealogics of race

Genealogy, or the study of one's ancestral patri-lineage, has a long and esteemed pedigree in French Canadian and Québécois history. From Cyprien Tanguay's late-nineteenth-century encyclopedias to René Jetté's updated versions more than a century later, genealogy has been an important component of French Canadian nationalisms. Tracing one's ancestry back to the early St. Lawrence settlement in the seventeenth century has provided Québécois subjects with opportune political and social capital with which to make territorial and national claims legitimate. Through a case study approach, I explain how genealogy provides the grounds upon which Québécois and French subjects remember a shared past. Specifically, I examine a variety of sites of memory in the French countryside, including a museum that relies on ‘genealogics’ to call the French Canadian Québécois back to its roots. As such, I demonstrate how the biological, read as a contemporary articulation of Balibar's notion of the racial supplément necessary to nation building, travels across the Atlantic.