Patterns in island endemic forest-dependent bird research: the Caribbean as a case-study

From Springer Nature via Jisc Publications RouterHistory: received 2018-10-25, rev-recd 2019-03-19, registration 2019-04-26, accepted 2019-04-26, online 2019-05-04, epub 2019-05-04, ppub 2019-06Publication status: PublishedAbstract: Unequal patterns in research effort can result in inaccurate assessments of species extinction risk or ineffective management. A group of notable conservation concern are tropical island endemic birds, many of which are also forest-dependent, which increases their vulnerability to extinction. Yet, island bird species have received limited research attention compared to their continental congeners, despite this taxon being globally regarded as well-studied. We used the insular Caribbean, a globally important endemism hotspot with high rates of deforestation, to explore research bias of island and regional endemic forest-dependent birds. A review of the published literature (n = 992) found no significant increase in the number of studies over the search period. Research effort was significantly higher among species with threatened status, long generation time, wide habitat breadth and low to intermediate elevational distributions. Among family groups, the Psittacidae received the highest research effort, while the Cuculidae were the most underrepresented family (30-fold higher and six-fold less than expected, respectively). We found geographic biases in effort, with Jamaica having six-fold less and Puerto Rico eight times more research than expected for their level of endemism. These patterns likely reflect individual interests and limited capacity and funding, typical of Small Island Developing States. With over 50% of species in this review having declining population trends, we recommend prioritizing research that emphasises conservation- and management-relevant data across underrepresented families and islands, by fostering greater collaboration between researchers, practitioners and the existing local amateur ornithological community

Protein homeostasis and aging in neurodegeneration

Genetic and environmental factors responsible for numerous neurodegenerative diseases vary between disorders, yet age remains a universal risk factor. Age-associated decline in protein homeostasis, or proteostasis, enables disease-linked proteins to adopt aberrant tertiary structures, accumulate as higher-ordered aggregates, and cause a myriad of cellular dysfunctions and neuronal death. However, recent findings suggest that the assembly of disease proteins into tightly ordered aggregates can significantly delay proteotoxic onset. Furthermore, manipulation of metabolic pathways through key signaling components extends lifespan, bolsters proteostasis networks, and delays the onset of proteotoxicity. Thus, understanding the relationship between proteostasis and aging has provided important insights into neurodegeneration

The Roles of Geographic Isolation and Gene Flow in the Diversification of the Rufous Fantail Rhipidura rufifrons

Studies of divergence and speciation patterns in island systems have played an important role in the development and establishment of the allopatric speciation model. However, recent empirical support for divergence and speciation with gene flow means the importance of isolation for divergence in island systems needs to be re-examined. Here I explore the roles of geographic isolation and gene flow in the early stages of divergence of evolutionarily independent replicate populations of the Rufous Fantail Rhipidura rufifrons on satellite islands in southeastern Solomon Islands. These populations differ in the extent of morphological divergence from the main island, providing a unique opportunity to test between modes of divergence in an island system. Patterns of population structure, gene flow, and the evolutionary history of the system were determined from one mtDNA and five nuclear genetic markers. Two demographic factors, gene flow and divergence time, are closely associated with neutral genetic divergence and may explain the pattern of morphological divergence across the system. Additionally, extensive morphological divergence in this system is only occurring between islands experiencing little gene flow, providing support for the prevalence of allopatric divergence in island systems.</p