Pollinator shifts are considered to drive floral trait evolution, yet little is still known about the modifications of petal epidermal surface at a biogeographic region scale. Here we investigated how independent shifts from insects to passerine birds in the Macaronesian Islands consistently modified this floral trait (i.e. absence of papillate cells). Using current phylogenies and extensive evidence from field observations, we selected a total of 81 plant species and subspecies for petal microscopy and comparative analysis, including 19 of the 23 insular species pollinated by opportunistic passerine birds (Macaronesian bird-flowered element). Species relying on passerine birds as the most effective pollinators (bird-pollinated) independently evolved at least five times and in all instances associated with a loss of papillate cells, whereas species with a mixed pollination system (birds plus insects and/or other vertebrates) evolved at least five times in Macaronesia and papillate cells were lost in only 25% of these transitions. Our findings suggest that petal micromorphology is a labile trait during pollinator shifts and that papillate cells tend to be absent on those species where pollinators have limited mechanical interaction with flowers, including opportunistic passerine birds that forage by hovering or from the ground.

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Background and Aims Alpine oceanic ecosystems are considered amongst the most ephemeral and restricted habitats, with a biota highly vulnerable to climate changes and disturbances. As an example of an alpine insular endemic, the past and future population genetic structure and diversity, and the future distribution of Viola cheiranthifolia (Violaceae), endemic to Tenerife (Canary Islands), were estimated. The main goals were to predict distribution changes of this alpine oceanic plant under climate change, and to assist in actions for its conservation. • Methods To perform population genetic analysis, 14 specific microsatellite markers and algorithms which considered the polyploid condition of V. cheiranthifolia were employed. The niche modelling approach incorporated temperature gradients, topography and snow cover maps. Models were projected into climate change scenarios to assess the extent of the altitudinal shifts of environmental suitability. Finally, simulations were performed to predict whether the environmental suitability loss will affect the genetic diversity of populations. • Key Results Viola cheiranthifolia presents short dispersal capacity, moderate levels of genetic diversity and a clear population genetic structure divided into two main groups (Teide and Las Cañadas Wall), showing signs of recolonization dynamics after volcanic eruptions. Future estimates of the distribution of the study populations also showed that, despite being extremely vulnerable to climate change, the species will not lose all its potential area in the next decades. The simulations to estimate genetic diversity loss show that it is correlated to suitability loss, especially in Las Cañadas Wall. • Conclusions The low dispersal capacity of V. cheiranthifolia, coupled with herbivory pressure, mainly from rabbits, will make its adaptation to future climate conditions in this fragile alpine ecosystem difficult. Conservation actions should be focused on herbivore control, population reinforcement and surveillance of niche shifts, especially in Guajara, which represents the oldest isolated population and a genetic reservoir for the species.

The translocation of individuals or the reinforcement of populations are measures in the genetic rescue of endangered species. Although it can be controversial to decide which and how many individuals must be reintroduced, populations can benefit from reinforcements. Sambucus palmensis is a critically endangered endemic to the Canary Islands. During the past 30 years, the Garajonay National Park (La Gomera) has carried out an intensive program of translocations using cuttings, due to the low germination rates of seeds. To assess the effect of the restorations on the population genetics of S. palmensis in La Gomera, we collected 402 samples from all the restored sites and all known natural individuals, which were genotyped with seven microsatellite markers. In addition, we conducted a species distribution modeling approach to assess how restorations fit the ecological niche of the species. Results show that there is a high proportion of clone specimens due to the propagation method, and the natural clonal reproduction of the species. Nonetheless, the observed heterozygosity has increased with the restorations and there still are private alleles and unique genotypes in the natural populations that have not been considered in the restorations. The population of Liria constitutes a very important genetic reservoir for the species. To optimize future reintroductions, we have proposed a list of specimens that are suitable for the extraction of seeds or cuttings in a greenhouse, as well as new suitable areas obtained by the species distribution models.

Aim Differentiation of island lineages from mainland relatives and radiation after initial colonization are two important processes generating island diversity. Both of these processes are influenced by colonization dynamics and contemporary connections between island species and their source populations. The classic island progression rule model, that is dispersal from mainland to older islands and subsequently to younger islands, can be considered a null hypothesis, particularly for islands that are geographically aligned perpendicular to the mainland coast with ages inversely proportional to distance from the mainland. Alterations to this pattern have been reported, particularly in archipelagos that are geographically closely adjacent to mainland source populations. Here we aim to integrate genomic and environmental niche data to infer the colonization history of a Canary endemic species and to understand its current diversity patterns. Location Canary Islands. Taxon Lavatera acerifolia (Malvaceae). Methods We used high‐throughput genotyping‐by‐sequencing (GBS) combined with species distribution modelling (SDM) projected onto past conditions. Genetic structure (clustering methods), relatedness (coalescent and ML trees), nucleotide diversity and differentiation (population genetics) were assessed based on SNPs obtained from three alternative bioinformatics pipelines. The influence of environmental variables over time was assessed with a generalized linear model in which the response variable was amount of heterozygous sites per individual. Results Four genetic groups were identified arranged along a longitudinal gradient, and the earliest diverging coincides with the older, and easternmost, islands (Lanzarote and Fuerteventura). Genetic diversity is reduced in the westernmost islands, which are more distant from the mainland, host few populations and yet apparently offer more suitable habitats. Main conclusions The inferred colonization scenario generally fits the progression rule model, but suggests a more complex pattern for the central islands. For the westernmost islands, the contrast between high availability of suitable habitats and reduced genetic diversity and number of populations suggests a colonization front moving at a slow pace, rather than local extinctions, as an explanation for the scarcity of populations in those islands. Historical projections of SDM lend support to this interpretation.