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We report the rediscovery of Lecocarpus leptolobus at its type locality, and restrict the latter to El Ripioso, San Cristóbal, Galapagos. We compare the morphology of the population at this site with other populations of Lecocarpus on San Cristóbal and other Galapagos islands. We conclude that L. leptolobus is a valid taxon endemic to the south-western half of San Cristóbal and is not synonymous with L. lecocarpoides, whereas populations further north-east on the same island constitute a separate species validly named L. darwinii. These two taxa support the idea of a former biogeographic barrier between the two halves of San Cristóbal. Plants at two of the easternmost localities of the south-western species show some characters intermediate between the two species, possibly representing introgression following easing of the barrier. The three specimens of Lecocarpus collected on San Cristóbal by Charles Darwin, all mounted on a single herbarium sheet, comprise one branch of L. leptolobus and two of L. darwinii. We identify possible sites for Darwin’s collections based on information about his explorations. We find grounds for accepting the taxon Acanthospermum brachyceratum as a subspecies of L. lecocarpoides endemic to Gardner-by-Española, Osborn and Xarifa islets, the first of these being the type locality, demonstrating that even narrow sea barriers can contribute to plant radiation in oceanic archipelagos. On the basis of our findings, we provide a new key to the taxa of Lecocarpus.

A recurring feature of oceanic archipelagos is the presence of adaptive radiations that generate endemic, species-rich clades that can offer outstanding insight into the links between ecology and evolution. Recent developments in evolutionary genomics have contributed towards solving long-standing questions at this interface. Using a comprehensive literature search, we identify studies spanning 19 oceanic archipelagos and 110 putative adaptive radiations, but find that most of these radiations have not yet been investigated from an evolutionary genomics perspective. Our review reveals different gaps in knowledge related to the lack of implementation of genomic approaches, as well as undersampled taxonomic and geographic areas. Filling those gaps with the required data will help to deepen our understanding of adaptation, speciation, and other evolutionary processes., D.D.C. was supported by a Humboldt postdoctoral fellowship. J.C. was supported by a Research Council of Norway travel grant (project 287327). J.C. thanks Andy Foote for early input and ideas on what a review encompasses. The authors are extremely grateful to four anonymous reviewers and the editor whose thoughtful criticism led to a significant improvement of this manuscript. This publication is contribution number 2488 of the Charles Darwin Foundation for the Galapagos Islands.

The genus

Oceanic archipelagos comprise multiple disparate environments over small geographic areas and are isolated from other biotas. These conditions have led to some of the most spectacular adaptive radiations, which have been key to our understanding of evolution, and offer a unique chance to characterise the genomic basis underlying rapid and pronounced phenotypic changes. Repeated patterns of evolutionary change in plants on oceanic archipelagos, i.e. the plant island syndrome, include changes in leaf morphology, acquisition of perennial life-style, and change of ploidy. Here, we describe the genome of the critically endangered and Galápagos endemic Scalesia atractyloides Arnot., obtaining a chromosome-resolved 3.2-Gbp assembly with 43,093 candidate gene models. Using a combination of fossil transposable elements, k-mer spectra analyses and orthologue assignment, we identify the two ancestral subgenomes and date their divergence and the polyploidization event, concluding that the ancestor of all Scalesia species on the Galápagos was an allotetraploid. There are a comparable number of genes and transposable elements across the two subgenomes, and while their synteny has been mostly conserved, we find multiple inversions that may have facilitated adaptation. We identify clear signatures of selection across genes associated with vascular development, life-growth, adaptation to salinity and changes in flowering time, thus finding compelling evidence for a genomic basis of island syndrome in Darwin’s giant daisy radiation. This work advances understanding of factors influencing subgenome divergence in polyploid genomes, and characterizes the quick and pronounced genomic changes in a specular and diverse radiation of an iconic island plant radiation.

Agriculture in the populated islands of the Galapagos Archipelago, a protected area due to its unique biodiversity, has been detrimental to its conservation but highly required to meet food necessities. A potential solution to make agricultural farming more sustainable is adopting water-saving technologies (WSTs). Therefore, this study aimed to test the effectiveness of using WSTs such as Groasis Waterboxx® in three of the most valuable crops in the islands through participatory research with the involvement of a group of farmers from the Floreana and Santa Cruz islands and explore a possible transition to more sustainable agricultural practices. Capsicum annuum, Cucumis sativus and Solanum lycopersicum were cultivated using Groasis Waterboxx® and compared to conventional irrigation practices (drip-irrigated controls) to assess the variability of productivity, the number of fruits and individual fruit weight (IFW). In addition, differences in plant traits were analyzed by crop, and island. Results suggested that WSTs such as Groasis Waterboxx® may provide on-farm benefits regarding the yields of the studied traits. From this study, it is difficult to determine whether participation in such a research study will permanently change irrigation practices. However, the participant’s responses to the study suggest an increase in their understanding of the use and benefits of WST.

The genus Kalanchoe, mostly indigenous from Madagascar and Tropical Africa, is widely traded for ornamental value. In this study, we provided an updated list of wild and cultivated Kal-anchoe taxa in Ecuador; we analyzed the temporal–spatial pattern of their records, and we categorized the invasion status for each taxon and its environment preferences. The records of any taxa belonging to this genus were compiled from an extensive search using various information sources. Our results confirmed the presence of 16 taxa of Kalanchoe in the country. Seven species and a hybrid were detected in the wild. Kalanchoe densiflora, K. laxiflora, K. pinnata, K. tubiflora, and K. ×houghtonii were categorized as invasive. We detected invasive records of some of these plants in protected areas. Almost all taxa had at least one record as cultivated, suggesting that the invasion pathway is ornamental trade. Kalanchoe pinnata individuals in the wild were recorded in the four biogeographic regions of Ecuador, which could be associated with the wide range of precipitations and tempera-tures in which the species may dwell. Our study highlights the importance of reducing the ornamental value and limiting the use of Kalanchoe taxa with invasive potential in horticulture and pro-moting, instead, the use of indigenous species., This project received financial support from Research Center of Universidad Espíritu Santo—Ecuador (project number: 2022-ING-002, to IH). Financial support also came from the Ministerio de Ciencia e Innovación—Spain (project PID2020-119163GB-I00 funded by MCIN/AEI/10.13039/501100011033)., 1. Introduction 2. Results 2.1. Richness of Kalanchoe Taxa in Ecuador 2.2. Key to Identify the Taxa of Kalanchoe Introduced in Ecuador Detected in theWild with Certainty 2.3. Temporal Accumulation and Distribution of Kalanchoe Records 2.4. Kalanchoe Taxa Categorized 2.5. Environmental Preferences 3. Discussion 3.1. Kalanchoe Taxa in Ecuador 3.2. Suggestions for Management 4. Materials and Methods 4.1. Study Area 4.2. List of Kalanchoe Taxa and Occurrences 4.3. Spatial–Temporal Distribution of the Records of Kalanchoe Taxa 4.4. Categorization of Kalanchoe Taxa by Invasion Status 4.5. Environmental Preferences Supplementary Materials Author Contributions Funding Data Availability Statement Acknowledgments Conflicts of Interest References

Part 1: The Evolutionary Context 1.1. What Darwin Found Convincing in Galapagos William Durham 1.2. Research on Evolutionary Principles in Galapagos: Research on Evolutionary Principles in Galapagos: An Overview of the Past 50 Years Carloss Valle and Patricia G. Parker 1.3. Evolution of Pathogens and Parasites on the Galapagos Islands Patricia G. Parker and Noah K. Whiteman 1.4. Turning Points in the Evolution of Vertebrates Eibl-Eibesfeld 1.5. The Boat, the Bay, and the Museum: Significance of the 1905-1906: Galapogos Expedition of the California Academy of Sciences Matthew James 1.6. Chapter Summary Part 2: Biodiversity Assessment and Monitoring of Change 2.1. Monitoring the Galapagos Ecosystem: Challenges, Pitfalls and a Vision for the Future James P. Gibbs and Bryan Milstead 2.2. The Neglected Majority - Biodiversity Inventories as an Integral Part of Conservation Biology Frank Bungartz 2.3. The Power of Long-Term Monitoring to Understand Mechanisms of Ecosystem Change: the Case of the Galapagos Marine Reserve Stuart Banks, Rodrigo Bustamante, Diego Ruiz, Natalia Tirado, Mariana Vera and Franz Smith 2.4. Wildlife Health Monitoringand Disease Management Protecting the Biodiversity of Galapagos Patricia G. Parker and Sharon L. Deem 2.5. Chapter Summary Part 3: A Systemic Approach: Modeling and Restoration 3.1. A Review of 40 Years of Eradication Programs in Galapagos: Impacts on the Whole Ecosystem Rachel Atkinson, Mark Gardener, Grant Harper and Victor Carrion 3.2. Food Web Structure of the Galapogas Pelagic Econosystem after a Decade of Protective Insights from Trophic Modelling Matthias Wolff and Cesar Penaherrera 3.3. Mediated Modelling: A System Dynamics Approach To Environmental Consensus Building for the Galapagos Marjan van den Belt 3.4. Chapter Summary Part 4: Reconciliation of the Conservation with Socio-Economic Development 4.1. The Value of Ecosystem Services and Biodiversity Conservation: A Challenge for the Galapagos Robert Costanza