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- Sir Joseph Hooker on insular floras: human impact and the natural laboratory paradigmPublication . Carine, Mark; Sequeira, Miguel Menezes deIn 1866, the botanist Joseph Dalton Hooker (1817-1911) delivered a lecture to the British Association for the Advancement of Science in Nottingham, U.K. entitled Insular floras. The lecture has been described as “the first systematic statement of the importance of islands for evolutionary studies”. As such, it can be seen to have contributed to the development of the “natural laboratory paradigm” that views islands as model systems for studying ecology and evolution. Hooker’s lecture also highlighted another key driver in shaping island diversity patterns, namely human impact. How and when does human impact compromise the uti lity of islands as ‘natural laboratories’ for studying evolution? To date, no fewer than eight “shortfalls” –knowledge gaps that impact on studies of biodiversity– have been described. In this paper, we suggest that a further shortfall is in order –a Hookerian shortfall– to account for uncertainty in the extent to which biodiversity patterns reflect natural rather than anthropogenic processes.
- Systematics, biogeography, and character evolution of the legume tribe Fabeae with special focus on the middle-Atlantic island lineagesPublication . Schaefer, Hanno; Hechenleitner, Paulina; Santos-Guerra, Arnoldo; Sequeira, Miguel Menezes de; Pennington, R. Toby; Kenicer, Gregory; Carine, MarkBackground: Tribe Fabeae comprises about 380 legume species, including some of the most ancient and important crops like lentil, pea, and broad bean. Breeding efforts in legume crops rely on a detailed knowledge of closest wild relatives and geographic origin. Relationships within the tribe, however, are incompletely known and previous molecular results conflicted with the traditional morphology-based classification. Here we analyse the systematics, biogeography, and character evolution in the tribe based on plastid and nuclear DNA sequences. Results: Phylogenetic analyses including c. 70% of the species in the tribe show that the genera Vicia and Lathyrus in their current circumscription are not monophyletic: Pisum and Vavilovia are nested in Lathyrus, the genus Lens is nested in Vicia. A small, well-supported clade including Vicia hirsuta, V. sylvatica, and some Mediterranean endemics, is the sister group to all remaining species in the tribe. Fabeae originated in the East Mediterranean region in the Miocene (23–16 million years ago (Ma)) and spread at least 39 times into Eurasia, seven times to the Americas, twice to tropical Africa and four times to Macaronesia. Broad bean (V. faba) and its sister V. paucijuga originated in Asia and might be sister to V. oroboides. Lentil (Lens culinaris ssp. culinaris) is of Mediterranean origin and together with eight very close relatives forms a clade that is nested in the core Vicia, where it evolved c. 14 Ma. The Pisum clade is nested in Lathyrus in a grade with the Mediterranean L. gloeosperma, L. neurolobus, and L. nissolia. The extinct Azorean endemic V. dennesiana belongs in section Cracca and is nested among Mediterranean species. According to our ancestral character state reconstruction results, ancestors of Fabeae had a basic chromosome number of 2n=14, an annual life form, and evenly hairy, dorsiventrally compressed styles. Conclusions: Fabeae evolved in the Eastern Mediterranean in the middle Miocene and spread from there across Eurasia, into Tropical Africa, and at least seven times to the Americas. The middle-Atlantic islands were colonized four times but apparently did not serve as stepping-stones for Atlantic crossings. Long-distance dispersal events are relatively common in Fabeae (seven per ten million years). Current generic and infrageneric circumscriptions in Fabeae do not reflect monophyletic groups and should be revised. Suggestions for generic level delimitation are offered.
- Documenting the flora of a diversity hotspot: Richard Thomas Lowe (1802–1874) and his botanical exploration of Madeira islandPublication . Mesquita, Sandra; Carine, Mark; Castel-Branco, Cristina; Sequeira, Miguel Menezes deOceanic island floras often exhibit remarkable concentrations of endemic diversity, provide spectacular examples of rapid evolutionary radiations and harbour floras under significant threat due to anthropogenic pressures. They have attracted the interest of biologists for centuries, but their floras continue to yield new taxa and, at a global scale, the extent of their plant diversity remains imperfectly known. Both natural characteristics and historical factors have shaped the development of knowledge of island floras. In this paper, we investigate the approach of Richard Thomas Lowe (1802–1874), to documenting the flora of Madeira island in the North Atlantic. Lowe collected abundantly in Madeira between 1826 and 1873, resulting in several works on Madeira’s flora, pub lished from the 1830s. At a time when taxonomic research on island floras was often based on limited collections made during brief expeditions, Lowe’s research on the flora, spanning almost half a century, was exceptional. In this study, 2579 herbarium specimens collected by Lowe were georeferenced and used to investigate temporal, spatial and taxonomic patterns in Lowe’s collecting activities. We also examine the distribution of specimens by Lowe to other botanists. Some biases are evident in Lowe’s collecting efforts, with steep slopes under-sampled and coastal sites over-sampled. These reflect constraints imposed by topography and transport links. These limitations aside, Lowe’s work on the Madeiran flora was conducted in a systematic manner, resulting in a comprehensive study of the entire flora. His approach was distinctly modern: he gathered and studied all available information in herbaria and in the pub lished and unpublished writings from earlier visitors; his initial fieldwork was conducted widely to gain knowledge of all habitats and their floras; later fieldwork focussed on less-explored and most promising areas; duplicates were sent to other botanists, facilitating taxonomic exchanges on critical taxa; and his later fieldwork focussed on plant groups where taxonomic problems had been detected. As a result of Lowe’s sustained and systematic approach, he is the single most prolific contributor to the study of Madeira’s endemic flora. His approach is a model to documenting island floras still relevant today. Areas poorly sampled by Lowe were areas that were difficult to access, which also protected them from anthropic destructive activities and allowed them to serve as refuges for endemic flora. Those areas deserve particular attention in efforts to complete the survey of Madeira’s plant diversity, using technological ad vancements such as drones to prospect areas that are otherwise still largely inaccessible.
- The Madeiran plants collected by Sir Hans Sloane in 1687, and his descriptionsPublication . Sequeira, Miguel Menezes de; Santos-Guerra, Arnoldo; Jarvis, Charles E.; Oberli, Andreas; Carine, Mark A.; Maunder, Michael; Francisco-Ortega, JavierThe Macaronesian Islands comprise the Atlantic archipelagos of Azores, Madeira, Selvagens, Canaries and Cape Verde. These islands were a major focus for plant exploration during the 17th and 18th centuries. Sir Hans Sloane (1660–1753), one of the most important patrons and sponsors of natural sciences and botanical research, visited Madeira on his way to Jamaica in 1687. Although he stayed in Madeira for only three days, he collected plant specimens of 38 taxa (including one brown alga) and made important observations concerning the flora and fauna of Madeira from near Funchal. Sixty-six polynomial names of plants from the island are recorded in Sloane’s published work along with 18 copperplate engravings, ostensibly from Madeira, although our study shows that only thirteen of them are of taxa occurring on the island. Fourteen of the sixty-six polynomials reported by Sloane relate to Macaronesian endemic taxa, six of them restricted to Madeira. Our study shows that nine of the fifteen polynomials that he putatively recorded for Madeira and/or the Antilles or for which he was unsure of their origin are from the West Indies and do not occur on this Macaronesian island. Two of the taxa that are listed for Madeira and the Carib bean Islands were likely to be present in both insular systems. Although there is evidence of earlier botanical explorations in Macaronesia, the herbarium collections made by Sloane in Madeira represent the earliest documented plant hunting expedition to Macaronesia, and Sir Hans Sloane can be considered as one of the pioneers of botanical exploration in these Atlantic Islands. Sloane’s records provide an early floristic study of a diverse island flora.