Reverse Genetics in Ecological Research

By precisely manipulating the expression of individual genetic elements thought to be important for ecological performance, reverse genetics has the potential to revolutionize plant ecology. However, untested concerns about possible side-effects of the transformation technique, caused by Agrobacterium infection and tissue culture, on plant performance have stymied research by requiring onerous sample sizes. We compare 5 independently transformed Nicotiana attenuata lines harboring empty vector control (EVC) T-DNA lacking silencing information with isogenic wild types (WT), and measured a battery of ecologically relevant traits, known to be important in plant-herbivore interactions: phytohormones, secondary metabolites, growth and fitness parameters under stringent competitive conditions, and transcriptional regulation with microarrays. As a positive control, we included a line silenced in trypsin proteinase inhibitor gene (TPI) expression, a potent anti-herbivore defense known to exact fitness costs in its expression, in the analysis. The experiment was conducted twice, with 10 and 20 biological replicates per genotype. For all parameters, we detected no difference between any EVC and WT lines, but could readily detect a fitness benefit of silencing TPI production. A statistical power analyses revealed that the minimum sample sizes required for detecting significant fitness differences between EVC and WT was 2–3 orders of magnitude larger than the 10 replicates required to detect a fitness effect of TPI silencing. We conclude that possible side-effects of transformation are far too low to obfuscate the study of ecologically relevant phenotypes

Local feeding specialization by badgers (Meles meles) in a mediterranean environment

A case of local feeding specialization in the European badger (Meles meles), a carnivore species with morphological, physiological and behavioural traits pro­ per to a trophic generalist, is described. For the first time, we report a mammalian species, the European rab­ bit (Oryctolagus cuniculus), as the preferred prey of bad­ gers. Secondary prey are consumed according to their availability, compensating for temporal fluctuations in the abundance of rabbit kittens. We discuss how both predator (little ability to hunt) and prey (profitability and predictability) features, may favour the observed special­ ization, as predicted by foraging theory. Badgers show a trend to specialize on different prey in different areas throughout the species range. It is suggested that changes in prey features can reverse the badger feeding strategy at the population level. Such dynamic behavioural re­ sponses make difficult to label badgers as generalists or specialists at the species levelPeer reviewe

Crônica de uma praga anunciada epidemias agrícolas e história ambiental do café nas Américas Chronicle of a plague foretold crop epidemics and the environmental history of coffee in the Americas

As epidemias agrícolas fornecem um ponto de vista privilegiado para a história ambiental global e transnacional de commodities. A epidemia da ferrugem, causada pelo fungo Hemileia nastatrix, é uma das mais sérias doenças que têm atingido a indústria global de café. No século XIX, ela devastou as plantações de café no Velho Mundo. Também reduziu agudamente a produção de café do tipo arábica na África, Ásia e no Pacífico. Esse foi um dos fatores que permitiu aos países da Américas dominarem a produção global no século XX. Essa epidemia foi detectada nas Américas pela primeira vez na década de 1970. A sua história nas Américas, e as tentativas de seu controle lançam luzes sobre dois paradigmas maiores que moldaram a história ambiental do café no final do século XX. São eles: o paradigma tecnicista, dominante entre meados do século XX até o início dos anos 1990; e o paradigma da sustentabilidade, cujo domínio emergiu em meados dos anos 1980 e se mantém até o presente.<br>Crop epidemics provide a portal into the global and transnational environmental history of commodities. The coffee rust epidemic, caused by the fungus Hemileia vastatrix, is one of the most serious diseases to have afflicted the global coffee industry. In the nineteenth century, it devastated the coffee plantations in the Old World. It sharply curtailed arabica coffee production in Africa, Asia, and the Pacific. This was one of the factors that allowed the Americas do dominate global coffee production in the twentieth century. The coffee rust epidemic was first detected in the Americas in the 1970s. The history of the rust epidemic in the Americas, and attempts to control it, shed light on two major paradigms that shaped the environmental history of coffee in the late twentieth century. The paradigm of technification, which dominated from the mid-20th century to the early 1990s; and the paradigm of sustainability, which dominated emerged in the mid-1980s and continues to the present