Immunological Change in a Parasite-Impoverished Environment: Divergent Signals from Four Island Taxa

Dramatic declines of native Hawaiian avifauna due to the human-mediated emergence of avian malaria and pox prompted an examination of whether island taxa share a common altered immunological signature, potentially driven by reduced genetic diversity and reduced exposure to parasites. We tested this hypothesis by characterizing parasite prevalence, genetic diversity and three measures of immune response in two recently-introduced species (Neochmia temporalis and Zosterops lateralis) and two island endemics (Acrocephalus aequinoctialis and A. rimitarae) and then comparing the results to those observed in closely-related mainland counterparts. The prevalence of blood parasites was significantly lower in 3 of 4 island taxa, due in part to the absence of certain parasite lineages represented in mainland populations. Indices of genetic diversity were unchanged in the island population of N. temporalis; however, allelic richness was significantly lower in the island population of Z. lateralis while both allelic richness and heterozygosity were significantly reduced in the two island-endemic species examined. Although parasite prevalence and genetic diversity generally conformed to expectations for an island system, we did not find evidence for a pattern of uniformly altered immune responses in island taxa, even amongst endemic taxa with the longest residence times. The island population of Z. lateralis exhibited a significantly reduced inflammatory cell-mediated response while levels of natural antibodies remained unchanged for this and the other recently introduced island taxon. In contrast, the island endemic A. rimitarae exhibited a significantly increased inflammatory response as well as higher levels of natural antibodies and complement. These measures were unchanged or lower in A. aequinoctialis. We suggest that small differences in the pathogenic landscape and the stochastic history of mutation and genetic drift are likely to be important in shaping the unique immunological profiles of small isolated populations. Consequently, predicting the impact of introduced disease on the many other endemic faunas of the remote Pacific will remain a challenge

What Policies Address Both the Coronavirus Crisis and the Climate Crisis?

The coronavirus pandemic has led many countries to initiate unprecedented economic recovery packages. Policymakers tackling the coronavirus crisis have also been encouraged to prioritize policies which help mitigate a second, looming crisis: climate change. We identify and analyze policies that combat both the coronavirus crisis and the climate crisis. We analyze both the long-run climate impacts from coronavirus-related economic recovery policies, and the impacts of long-run climate policies on economic recovery and public health post-recession. We base our analysis on data on emissions, employment and corona-related layoffs across sectors, and on previous research. We show that, among climate policies, labor-intensive green infrastructure projects, planting trees, and in particular pricing carbon coupled with reduced labor taxation boost economic recovery. Among coronavirus policies, aiding services sectors (leisure services such as restaurants and culture, or professional services such as technology), education and the healthcare sector appear most promising, being labor intensive yet low-emission—if such sectoral aid is conditioned on being directed towards employment and on low-carbon supply chains. Large-scale green infrastructure projects and green R&D investment, while good for the climate, are unlikely to generate enough employment to effectively alleviate the coronavirus crisis