Immunoglobulin haplotypes: markers of reproductive success?

Immunoglobulin haplotypes are highly polymorphic and are useful for analyses of both macro- and microdifferentiation of populations. The origins of this diversity are not known, but recent reports suggest strong selection at this locus. Increased rates of first-trimester spontaneous abortions have been reported when parents share GM phenotypes. Reduced fertility has been observed in mixed European descent white and Hutterite populations when both parents share immunoglobulin haplotypes. Population samples with completed family information and GM haplotype data are rare; the objective here is to provide this information on another sample. A sample of 242 Mennonite couples with mothers older than 40 years was divided into 3 groups of matings based on how many haplotypes were shared: 0, 1, or 2. The distribution of mean completed family sizes for the three groups were 3.35 +/- 1.85 (n = 23), 3.47 +/- 1.69 (n = 128), and 3.37 +/- 1.60 (n = 91), respectively; these values were not significantly different (F = 0.145, p = 0.865). The log-rank test was used to compare the time-to-next-birth curves. The intervals between first and later births (2-4 births) were not significantly different for the three subgroups either. There is also only limited evidence for segregation distortion in another sample of 923 offspring (in which at least one parent is heterozygous.     

Antibacterial discovery and development--the failure of success?

A combination of approaches and compounds-many of which failed to yield immediate results in the past-will ultimately prove invaluable to the drug industry in the ongoing battle against infectious disease.     

What controls liana success in Neotropical forests?

Aim   We seek to determine the factors which control the success of lianas across macroecological gradients. Lianas have a strong impact on the growth, mortality and biomass of tropical trees, and are reported to be increasing in dominance, so understanding their behaviour is important from the perspectives of both ecological and global change.
Location   Lowland and montane Neotropical forests.
Methods   Using 65 standardized samples of lianas (≥ 2.5 cm diameter) from across the Neotropics, we attempted to account for characteristics of both the environment and the forest in explaining macroecological variation in liana success in Neotropical forests, using regression analyses and structural equation modelling.
Results   We found that both liana density and basal area were unrelated to mean annual precipitation, dry season length or soil variables, except for a weak effect of mean annual precipitation on liana basal area. Structural characteristics of the forest explained more of the variation in liana density and basal area than the physical environment. More disturbed forests generally tended to have a higher liana density. Liana basal area, however, was highest in undisturbed forests.
Main conclusions   The availability of host trees and their characteristics may be more important than the direct effects of the physical environment in controlling the success of lianas in Neotropical forests. Changes to the tropical climate in the coming century may not strongly affect lianas directly, but could have very substantial indirect effects via changes in tree community structure and dynamics.     

Treatment of melanoma; success or failure?

The treatment of melanoma should be by radical surgical excision of the primary lesion and dissection of the regional nodes. Where possible this should be done in anatomic continuity; otherwise in physical discontinuity but at the same time. If maximum salvage is to be achieved the nodal dissection must be effected before there is clinical evidence of involvement by metastasis. Amputation of extremities should be reserved for cases in which there is evident metastasis between the original focus and the regional lymph node areas.     

Are there any consistent predictors of invasion success?

This article summarises the results of 49 studies that together test the significance of 115 characteristics in 7 biological groups: birds, finfish, insects, mammals, plants, reptiles/amphibians and shellfish. Climate/habitat match, history of invasive success and number of arriving/released individuals are associated with establishment success in at least four independent data sets, both within and across biological groups, and none are contraindicated by other studies. In the introduced-invasive control group, two species level characteristics—taxon and geographic range size—were significantly associated with establishment success across two biological groups. These characteristics, however, were not supported by independent data sets, or were contraindicated by these data sets, within the biological groups examined here. In the introduced-native control group, three species level characteristics—geographic range size, leaf surface area and fertilisation system (monoecious, hermaphroditic or dioecious)—were consistently supported within plants but were either not supported by independent data sets or contraindicated by datasets within or across other biological groups. Climate/habitat match is the only characteristic that is consistently significantly associated with invasive behaviour (in this case exotic range size) across biological groups. This finding, however, is not supported by two or more independent data sets within any of the biological groups examined here. Within plants there are a suite of characteristics, predominately associated with reproduction, that are significantly associated with a range of invasion metrics, predominately abundance in the invaded range. None of these characteristics, however, are supported across any other biological groups. We note the confounding effects of phylogeny, residence time and propagule pressure and suggest that site- and taxa-specific analysis will provide further useful insights.     

Why do good hunters have higher reproductive success?

Anecdotal evidence from many hunter-gatherer societies suggests that successful hunters experience higher prestige and greater reproductive success. Detailed quantitative data on these patterns are now available for five widely dispersed cases (Ache, Hadza, !Kung, Lamalera, and Meriam) and indicate that better hunters exhibit higher age-corrected reproductive success than other men in their social group. Leading explanations to account for this pattern are: (1) direct provisioning of hunters’ wives and offspring, (2) dyadic reciprocity, (3) indirect reciprocity, (4) costly signaling, and (5) phenotypic correlation. I examine the qualitative and quantitative evidence bearing on these explanations and conclude that although none can be definitively rejected, extensive and apparently unconditional sharing of large game somewhat weakens the first three explanations. The costly signaling explanation has support in some cases, although the exact nature of the benefits gained from mating or allying with or deferring to better hunters needs further study. For comments on earlier drafts, I thank Monique Borgerhoff Mulder, Mike Gurven, Ray Hames, Kristen Hawkes, Kim Hill, Robert Kelly, Frank Marlowe, John Patton, and Polly Wiessner. Rebecca Bliege Bird and Douglas W. Bird invited me to collaborate in the Meriam research and (along with Del Passi of Mer) collected the data on Meriam demography. Geoff Kushnick and Matt Wimmer ably assisted with coding and statistical analysis of these data. Eric Alden Smith (PhD 1980, Cornell University) is a professor of anthropology at the University of Washington, Seattle. His research interests include the links between production and reproduction, the ecology and evolution of collective action, and politics in small-scale societies. He has conducted fieldwork among Inuit on Hudson Bay, Meriam in Torres Strait, and Mardu Aborigines in the Australian Western Desert.     

Is female attractiveness related to final reproductive success?

In order to test the assumption that female attractiveness relates to reproductive success, photographs of 47 rural Polish women taken in their youth were rated for attractiveness, and BMI at age 18 was recorded; these measures of attractiveness were then compared with their subsequent life histories. Facial attractiveness did not relate to number of children or grandchildren. It also did not relate to age of marriage or husband's education. It did relate to number of marriages and husband's height. BMI at age 18 did not relate significantly to any of the outcome variables. These results suggest that although more attractive women may have married higher quality (taller) husbands and may in ancestral population have achieved greater reproductive success this way, there is no evidence in a modern, European Catholic society for their having greater reproductive success.     

May random processes explain mating success in leks?

The object of this paper is to verify whether in specific cases the variance of mating success among lekking males may be due exclusively to a random mechanism, as opposed to the adaptive mechanisms of mate choice which are usually postulated in the literature in the framework of sexual selection theory. In fact, some studies attempted to compare observed distributions of male mating success with a Poisson ‘null’ distribution based on the conjecture of random mating; the conjecture is usually rejected. In this paper we construct a plausible model (the ‘null’ hypothesis) for a strictly random non-adaptive pattern of social behaviour of lekking males and females and we perform several simulations for reasonable choices of parameter values. It should be observed that some of the simulations based on our random model lead to a distribution of male mating success which is Poisson-like. However, contrary to predictions, in several simulations a random process of mate choice lead to non-Poissonian distributions. Accordingly, the fact that, when performing a statistical test on several sets of field data, we find both cases which are in agreement with Poisson distribution, or a normal one, and cases which are not, does not allow us to reject the assumption of random male reproductive success. Thus it is legitimate to conjecture that in many cases the inter-individual variability of male mating success might indeed be determined by random processes. If this conjecture were to be confirmed by further studies, the actual significance of sexual selection in the evolution of lekking species should be reassessed, and a novel approach in the analysis of field data would be called for.     

Could bacterial associations determine the success of weevil species?

The weevil superfamily Curculionoidea is the largest insect group and so the largest animal group on earth. This taxon includes species which represent an important threat to many economically important crops and, therefore, pose a risk to agriculture and food security. Insect–bacteria associations have been recognised to provide the insect host with many benefits, such as ensuring the acquisition of essential nutrients or protecting the host from natural enemies. The role of bacteria associations within the weevil superfamily remains nonetheless understudied in comparison with other insect taxa. This review draws together existing knowledge on the influence of bacteria associated with weevils known to be agricultural pest species. The implications of these weevil–bacterial associations in determining pest status and their relevance to targeted pest management interventions are discussed. Specific consideration is given to the role of bacteria in cuticle formation, flight activity, reproduction manipulation and adaptation to different environments and food sources.     

Is invasion success explained by the enemy release hypothesis?

A recent trend in invasion ecology relates the success of non‐indigenous species (NIS) to reduced control by enemies such as pathogens, parasites and predators (i.e. the enemy release hypothesis, ERH). Despite the demonstrated importance of enemies to host population dynamics, studies of the ERH are split – biogeographical analyses primarily show a reduction in the diversity of enemies in the introduced range compared with the native range, while community studies imply that NIS are no less affected by enemies than native species in the invaded community. A broad review of the invasion literature implies at least eight non‐exclusive explanations for this enigma. In addition, we argue that the ERH has often been accepted uncritically wherever (i) NIS often appear larger, more fecund, or somehow ‘better’ than either congeners in the introduced region, or conspecifics in the native range; and (ii) known enemies are conspicuously absent from the introduced range. However, all NIS, regardless of their abundance or impact, will lose natural enemies at a biogeographical scale. Given the complexity of processes that underlie biological invasions, we argue against a simple relationship between enemy ‘release’ and the vigour, abundance or impact of NIS.     

What would constitute success for UK biotechnology in 2005?

This paper presents the rationale and results of a scenario exercise concerning possible future developments in UK biotechnology. The final output of this exercise is a 'consensus' vision of what success might look like for the UK in biotechnology in 2005. The 'success scenario' was developed during a two-day workshop through structured discussions in a group of people active in biotechnology in industry, research agencies, consultancies or academe.     

Genomics: success or failure to deliver drug targets?

For decades, the entire pharmaceutical industry has focused on a limited number of drug targets. Owing to advances in molecular biology and genome technology at the beginning of the 1990s, discovery and isolation of a large number of genes from the human genome became feasible. This triggered a multi billion US dollars investment by both biotechnology and pharmaceutical companies to gain access to and patent as many potential drug targets as possible. Although the combined effort of publicly funded projects and private investments resulted in rapid identification of essentially all genes of the human genome, harnessing this information to enable drug discovery has turned out to be more challenging and time consuming than initially anticipated.     

A program for successful muskellunge management—A Minnesota success story

Minnesota has established a successful muskellunge, Esox masquinongy, stocking program as a result of a series of research studies that enabled area fisheries managers to make informed management decisions. The previous propagation and stocking program (pre-1982) reared muskellunge progeny from Shoepack Lake near the Minnesota–Ontario border, but these fish were not attaining trophy size. Protein electrophoresis showed there were two different muskellunge strains in the state. A controlled study was conducted on progeny from natural muskellunge populations from Leech and Shoepack lakes. Fish from these populations, together, were used to stock two other Minnesota lakes, and their growth rates, age of maturity, and maximum size attained were compared. Leech Lake muskellunge grew faster and attained a larger maximum size than the Shoepack Lake strain. As a result, a new stocking program based on the Leech Lake strain was developed. Because it was difficult to collect Leech Lake gametes, the Minnesota Department of Natural Resources created seven brood stock lakes using Leech Lake progeny. As a result of combining genetic considerations, new research on spawning sites, more restrictive harvest regulations, and catch-and-release fishing, anglers’ catch of trophy-sized muskellunge in Minnesota has increased.     

Does restoration work? It depends on how we measure success

The restoration of 4 partial stream barriers was evaluated in watersheds of Terra Nova National Park, Newfoundland, Canada from 2009 to 2011. Brook trout (n = 462) were tagged and tracked moving through our study sites using passive‐integrated transponder telemetry and the restoration actions were assessed using 3 different measures: passage success rates; the range of passable flows; and the availability of passable flows. We considered the observed results within a before‐after‐control‐impact (BACI) design that included reference reaches and pre‐restoration observations. The conclusions of BACI analyses were also contrasted with those that would have been obtained from commonly used before‐after (B‐A) or control‐impact (C‐I) study designs. While the restoration actions changed hydrological conditions in a way that should facilitate fish passage, our biological measures indicated that success was variable across culverts and within culverts depending on the measure evaluated. Furthermore, the natural temporal and spatial variability of fish movements often resulted in different conclusions between the more robust BACI design and the more commonly used B‐A and C‐I designs. Our results demonstrate that restoration of partial barriers may not always yield dramatic improvements. Furthermore, without suitable controls, the chances of drawing false conclusions regarding restorations in temporally and spatially dynamic systems are substantial.