Reproductive ecology of Naididae (Oligochaeta)

Asexual reproduction is employed by species of Naididae during favorable environmental conditions. In species characteristic of aquatic habitats subject to rapid fluctuations in water levels and temperatures most individuals in a population become sexually mature, and there is degeneration of the alimentary tract, a shortened breeding season, and aclitellar formation of cocoons. Cocoon deposition allows a population to survive periods of environmental stress. Sexual reproduction predominates near the edges of ranges where stress conditions are more prevalent. Species that reproduce sexually in spring are intolerant of summer conditions, while those that breed in autumn are intolerant of winter. Species typical of environmentally stable bodies of water usually have a minority of the population mature at any time, an extended breeding season, and the ability to continue feeding while mature; thus, adaptations for survival in unstable habitats are lacking.     

The dicey dinner dilemma: Asymmetry in predator–prey risk‐taking,a broadly applicable alternative to the life‐dinner principle

Forty years ago, the ‘life‐dinner principle’ was proposed as an example of an asymmetry that may lead prey species to experience stronger selection than their predators, thus accounting for the high frequency with which prey escape alive from interaction with a predator. This principle remains an influential concept in the scientific literature, despite several works suggesting that the concept relies on many under‐appreciated assumptions and does not apply as generally as was initially proposed. Here, we present a novel model describing a very different asymmetry to that proposed in the life‐dinner principle, but one that could apply broadly. We argue that asymmetries between the relative costs and benefits to predators and prey of selecting a risky behaviour during an extended predator–prey encounter could lead to an enhanced likelihood of escape for the prey. Any resulting advantage to prey depends upon there being a behaviour or choice that introduces some inherent danger to both predator and prey if they adopt it, but which if the prey adopts the predator must match in order to have a chance of successful predation. We suggest that the circumstances indicated by our model could apply broadly across diverse taxa, including both risky spatial or behavioural choices.     

Male phenotypes in a female framework: Evidence for degeneration in sperm produced by male snails from asexual lineages

How changes in selective regimes affect trait evolution is an important open biological question. We take advantage of naturally occurring and repeated transitions from sexual to asexual reproduction in a New Zealand freshwater snail species, Potamopyrgus antipodarum, to address how evolution in an asexual context—including the potential for relaxed selection on male‐specific traits—influences sperm morphology. The occasional production of male offspring by the otherwise all‐female asexual P. antipodarum lineages affords a unique and powerful opportunity to assess the fate of sperm traits in a context where males are exceedingly rare. These comparisons revealed that the sperm produced by ‘asexual’ males are markedly distinct from sexual counterparts. We also found that the asexual male sperm harboured markedly higher phenotypic variation and was much more likely to be morphologically abnormal. Together, these data suggest that transitions to asexual reproduction might be irreversible, at least in part because male function is likely to be compromised. These results are also consistent with a scenario where relaxed selection and/or mutation accumulation in the absence of sex translates into rapid trait degeneration.     

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.     

中国云南色串孢科的新种苍山长喙孢和新记录露

本研究对中国滇西北地区淡水木腐真菌进行了调查,在云南省的苍山、怒江和澜沧江采集到3个菌株。根据形态学特征和多基因系统发育分析（ITS、LSU、SSU、TEF1-α和RPB2）描述了新种——苍山长喙孢Rostriconidium cangshanense。苍山长喙孢的特征是菌体形态与营养菌丝不同,分生孢子梗单生或者松散成束,光滑或粗糙;产孢细胞多芽、深褐色、具有黑色驼峰状的分生孢子脱落痕;分生孢子梭形至倒棒状、长喙状,6-8个横隔,有明显油滴状细胞内含物,有时具顶端粘膜鞘。露兜长喙孢Rostriconidium pandanicola报道为世界淡水环境的新记录。     

Access to Music Education with Regard to Race in Two Urban Areas

This quantitative study examined access to school music instruction with regard to race in two urban areas: Detroit, Michigan, and Washington, DC, in 2009–2010. We found significant differences in the provision of music instruction between schools with high and low proportions of nonwhite enrollment, in categories including curricular offerings, extracurricular offerings, and resources. In the Detroit area, only 31 percent to 60 percent of schools with high percentages of nonwhite students offered any music instruction at all. We contrast our findings with those of a National Center for Educational Statistics report to demonstrate how regional and national averages can obscure information that should guide policy, such as the influence of location and racial demographics of schools on the provision of public school music instruction. The article concludes with a discussion of the implications of using flawed data in the creation of policy and suggestions for more comprehensive and accurate data collection and analysis.     

A Cross-Sectional Epidemiological Study of Prevalence and Severity of Bit-Induced Oral Trauma in Polo Ponies and Race Horses

Bit and bridle accessories improperly fitted in ridden horses can cause oral trauma such as bone spurs, commissure ulceration, and tongue lacerations. This study was used to identify, grade, and compare the types of oral traumas commonly found within polo ponies and race horses. Injuries were assessed visually and by palpation on the tongue, lips’ commissures, and interdental space. A total of 50 polo ponies and 50 race horses were sampled in the South of England. A Poisson model was successfully fitted to the data (p < .001), and the variables of discipline (p < .001), injury type (p < .001), and age (p < .001) were significant. Race horses with snaffle bits were predisposed to significantly higher severities and prevalence of oral trauma than were polo ponies in gag bits. Only polo ponies were observed with tongue trauma. Race horses had higher severities of injuries in the commissures and bone spurs. Positive correlations were found between age and/or time in sport and induced biting injuries. Polo ponies had been playing longer before the occurrence of injuries.     

Whiteness studies and laypeople's engagements with race and genetics

This paper proposes a research strategy for examining laypeople's thoughts and reflections on innovations in the science of race and genetics. While some sociologists have shown a reluctance to engage in such discussions, this paper argues that social scientists need to take such views seriously. To do this, the paper brings together an anthropological approach to the study of scientific literacy and recent scholarship in the field of Whiteness studies. The combining of these literatures raises a set of interesting and sometimes uncomfortable questions about the ways in which social scientists and research participants contribute to the reproduction of White power and dominance in Western societies.