The emerging structure of the Extended Evolutionary Synthesis: where does Evo-Devo fit in?

The Extended Evolutionary Synthesis (EES) debate is gaining ground in contemporary evolutionary biology. In parallel, a number of philosophical standpoints have emerged in an attempt to clarify what exactly is represented by the EES. For Massimo Pigliucci, we are in the wake of the newest instantiation of a persisting Kuhnian paradigm; in contrast, Telmo Pievani has contended that the transition to an EES could be best represented as a progressive reformation of a prior Lakatosian scientific research program, with the extension of its Neo-Darwinian core and the addition of a brand-new protective belt of assumptions and auxiliary hypotheses. Here, we argue that those philosophical vantage points are not the only ways to interpret what current proposals to ‘extend’ the Modern Synthesis-derived ‘standard evolutionary theory’ (SET) entail in terms of theoretical change in evolutionary biology. We specifically propose the image of the emergent EES as a vast network of models and interweaved representations that, instantiated in diverse practices, are connected and related in multiple ways. Under that assumption, the EES could be articulated around a paraconsistent network of evolutionary theories (including some elements of the SET), as well as models, practices and representation systems of contemporary evolutionary biology, with edges and nodes that change their position and centrality as a consequence of the co-construction and stabilization of facts and historical discussions revolving around the epistemic goals of this area of the life sciences. We then critically examine the purported structure of the EES—published by Laland and collaborators in 2015—in light of our own network-based proposal. Finally, we consider which epistemic units of Evo-Devo are present or still missing from the EES, in preparation for further analyses of the topic of explanatory integration in this conceptual framework

The Allometry of Host-Pathogen Interactions

Understanding the mechanisms that control rates of disease progression in humans and other species is an important area of research relevant to epidemiology and to translating studies in small laboratory animals to humans. Body size and metabolic rate influence a great number of biological rates and times. We hypothesize that body size and metabolic rate affect rates of pathogenesis, specifically the times between infection and first symptoms or death.We conducted a literature search to find estimates of the time from infection to first symptoms (t(S)) and to death (t(D)) for five pathogens infecting a variety of bird and mammal hosts. A broad sampling of diseases (1 bacterial, 1 prion, 3 viruses) indicates that pathogenesis is controlled by the scaling of host metabolism. We find that the time for symptoms to appear is a constant fraction of time to death in all but one disease. Our findings also predict that many population-level attributes of disease dynamics are likely to be expressed as dimensionless quantities that are independent of host body size.Our results show that much variability in host pathogenesis can be described by simple power functions consistent with the scaling of host metabolic rate. Assessing how disease progression is controlled by geometric relationships will be important for future research. To our knowledge this is the first study to report the allometric scaling of host/pathogen interactions

Efeito do extrato aquoso da Hyptis pectinata na regeneração hepática após hepatectomia parcial em ratos

Objetivo: Este estudo foi realizado com o objetivo de verificar o efeito do extrato aquoso da Hyptis pectinata na regeneração hepática bem como nos níveis das enzimas séricas (AST, ALT e γ-GT) após hepatectomia parcial de 67% em ratos. Métodos: AST, ALT e γ-GT, foram determinadas pelo método cinético utilizando um espectrofotômetro (Modelo E2250- CELM). A regeneração hepática foi avaliada por imunohistoquímica (PCNA). Resultados: O pré-tratamento oral de 100 mg/ kg foi realizado durante 4 dias e causou aumento na regeneração hepática O pré-tratamento oral com 200 mg/kg diminuiu significativamente os níveis de AST quando comparado com o grupo submetido ao pré-tratamento com água destilada. As demais enzimas avaliadas não apresentaram diferenças quando comparadas entre os grupos estudados. Conclusão: O presente estudo mostra que o extrato aquoso da Hyptis pectinata, numa concentração de 100 mg/kg possui alguma atividade biológica estimulando a regeneração hepática e causando também um leve efeito hepatoprotetor numa concentração de 200 mg/kg. _________________________________________________________________________________________ ABSTRACT: Purpose: This study was carried out to assess the effects of the aqueous extract of Hyptis pectinata leaves on liver regeneration and on serum enzymes (AST, ALT and γ-GT) after 67% partial hepatectomy in rats. Methods: AST, ALT and γ-GT, were determined by conventional procedures using a spectrophotometer (Model E2250-CELM). Liver regeneration was evaluated by immunohistochemical staining for proliferating cell nuclear antigen (PCNA). Results:Oral pretreatment during 4 days at 100 mg/kg increased liver regeneration index. At 200 mg/kg, AST level was statistically decreased in comparison to the group submited to distilled water administration. The other enzymes assessed disclosed no difference when all groups were compared. Conclusion: The present study shows that the aqueous extract of Hyptis pectinata leaves contains some biological active principles that stimulate liver regeneration at 100 mg/kg and cause slight hepatic protection at 200 mg/kg

Genetic parameters for body weight, carcass chemical composition and yield in a broiler-layer cross developed for QTL mapping

The objective of this study was to estimate genetic and phenotypic correlations of body weight at 6 weeks of age (BW6), as well as final carcass yield, and moisture, protein, fat and ash contents, using data from 3,422 F2 chickens originated from reciprocal cross between a broiler and a layer line. Variance components were estimated by the REML method, using animal models for evaluating random additive genetic and fixed contemporary group (sex, hatch and genetic group) effects. The heritability estimates (h2) for BW6, carcass yield and percentage of carcass moisture were 0.31 ± 0.07, 0.20 ± 0.05 and 0.33 ± 0.07, respectively. The h2 for the percentages of protein, fat and ash on a dry matter basis were 0.48 ± 0.09, 0.55 ± 0.10 and 0.36 ± 0.08, respectively. BW6 had a positive genetic correlation with fat percentage in the carcass, but a negative one with protein and ash contents. Carcass yield, thus, appears to have only low genetic association with carcass composition traits. The genetic correlations observed between traits, measured on a dry matter basis, indicated that selection for carcass protein content may favor higher ash content and a lower percentage of carcass fat

Phenotypes of lung mononuclear phagocytes in HIV seronegative tuberculosis patients: evidence for new recruitment and cell activation

Mycobacterium tuberculosis preferentially resides in mononuclear phagocytes. The mechanisms by which mononuclear phagocytes keep M. tuberculosis in check or by which the microbe evades control to cause disease remain poorly understood. As an initial effort to delineate these mechanisms, we examined by immunostaining the phenotype of mononuclear phagocytes obtained from lungs of patients with active tuberculosis. From August 1994 to March 1995, consecutive patients who had an abnormal chest X-ray, no demostrable acid-fast bacilli in sputum specimens and required a diagnostic bronchoalveolar lavage (BAL) were enrolled. Of the 39 patients enrolled, 21 had microbiologically diagnosed tuberculosis. Thirteen of the 21 tuberculosis patients were either HIV seronegative (n = 12) or had no risk factor for HIV and constituted the tuberculosis group. For comparison, M. tuberculosis negative patients who had BAL samples taken during this time (n = 9) or normal healthy volunteers (n = 3) served as control group. Compared to the control group, the tuberculosis group had significantly higher proportion of cells expressing markers of young monocytes (UCHM1) and RFD7, a marker for phagocytic cells, and increased expression of HLA-DR, a marker of cell activation. In addition, tuberculosis group had significantly higher proportion of cells expressing dendritic cell marker (RFD1) and epithelioid cell marker (RFD9). These data suggest that despite recruitment of monocytes probably from the peripheral blood and local cell activation, host defense of the resident lung cells is insufficient to control M. tuberculosis

A FRUITFULL-like gene is associated with genetic variation for fruit flesh firmness in apple (Malus domestica Borkh.)

The FRUITFULL (FUL) and SHATTERPROOF (SHP) genes are involved in regulating fruit development and dehiscence in Arabidopsis. We tested the hypothesis that this class of genes are also involved in regulating the development of fleshy fruits, by exploring genetic and phenotypic variation within the apple (Malus domestica) gene pool. We isolated and characterised the genomic sequences of two candidate orthologous FUL-like genes, MdMADS2.1 and MdMADS2.2. These were mapped using the reference population ‘Prima x Fiesta’ to loci on Malus linkage groups LG14 and LG06, respectively. An additional MADS-box gene, MdMADS14, shares high amino acid identity with the Arabidopsis SHATTERPROOF1/2 genes and was mapped to Malus linkage group LG09. Association analysis between quantitative fruit flesh firmness estimates of ‘Prima x Fiesta’ progeny and the MdMADS2.1, MdMADS2.2 and MdMADS14 loci was carried out using a mixed model analysis of variance. This revealed a significant association (P < 0.01) between MdMADS2.1 and fruit flesh firmness. Further evidence for the association between MdMADS2.1 and fruit flesh firmness was obtained using a case–control population-based genetic association approach. For this, a polymorphic repeat, (AT)n, in the 3′ UTR of MdMADS2.1 was used as a locus-specific marker to screen 168 apple accessions for which historical assessments of fruit texture attributes were available. This analysis revealed a significant association between the MdMADS2.1 and fruit flesh firmness at both allelic (χ 2 = 34, df = 9, P < 0.001) and genotypic (χ 2 = 57, df = 32, P < 0.01) levels