Modularity and evolution of flower shape: the role of function, development, and spandrels in Erica.

Flowers have been hypothesized to contain either modules of attraction and reproduction, functional modules (pollination-effecting parts) or developmental modules (organ-specific). Do pollination specialization and syndromes influence floral modularity? In order to test these hypotheses and answer this question, we focused on the genus Erica: we gathered 3D data from flowers of 19 species with diverse syndromes via computed tomography, and for the first time tested the above-mentioned hypotheses via 3D geometric morphometrics. To provide an evolutionary framework for our results, we tested the evolutionary mode of floral shape, size and integration under the syndromes regime, and - for the first time - reconstructed the high-dimensional floral shape of their most recent common ancestor. We demonstrate that the modularity of the 3D shape of generalist flowers depends on development and that of specialists is linked to function: modules of pollen deposition and receipt in bird syndrome, and access-restriction to the floral reward in long-proboscid fly syndrome. Only size and shape principal component 1 showed multiple-optima selection, suggesting that they were co-opted during evolution to adapt flowers to novel pollinators. Whole floral shape followed an Ornstein-Uhlenbeck (selection-driven) evolutionary model, and differentiated relatively late. Flower shape modularity thus crucially depends on pollinator specialization and syndrome.

Endemic diversity and distribution of the Iranian vascular flora across phytogeographical regions, biodiversity hotspots and areas of endemism.

Endemism is one of the most important concepts in biogeography and is of high relevance for conservation biology. Nevertheless, our understanding of patterns of endemism is still limited in many regions of high biodiversity. This is also the case for Iran, which is rich in biodiversity and endemism, but there is no up-to-date account of diversity and distribution of its endemic species. In this study, a comprehensive list of all endemic vascular plant species of Iran, their taxonomic composition and their geographical distribution are presented. To this end, a total of 2,597 (sub)endemic vascular plant species of Iran were documented and their distribution in three phytogeographical regions, two biodiversity hotspots and five areas of endemism were analysed. The Irano-Turanian phytogeographical region harbours 88% of the Iranian endemics, the majority of which are restricted to the Irano-Anatolian biodiversity hotspot (84%). Nearly three quarters of the endemic species are restricted to mountain ranges. The rate of endemism increases along an elevational gradient, causing the alpine zone to harbour a disproportionally high number of endemics. With increasing pastoralism, urbanization, road construction and ongoing climate change, the risk of biodiversity loss in the Iranian mountains is very high, and these habitats need to be more effectively protected.

Visions of the past and dreams of the future in the Orient: the Irano-Turanian region from classical botany to evolutionary studies.

Ever since the 19th century, the immense arid lands of the Orient, now called the Irano-Turanian (IT) floristic region, attracted the interest of European naturalists with their tremendous plant biodiversity. Covering approximately 30% of the surface of Eurasia (16000000 km2 ), the IT region is one of the largest floristic regions of the world. The IT region represents one of the hotspots of evolutionary and biological diversity in the Old World, and serves as a source of xerophytic taxa for neighbouring regions. Moreover, it is the cradle of the numerous species domesticated in the Fertile Crescent. Over the last 200 years, naturalists outlined different borders for the IT region. Yet, the delimitation and evolutionary history of this area remain one of the least well-understood fields of global biogeography, even though it is crucial to explaining the distribution of life in Eurasia. No comprehensive review of the biogeographical delimitations nor of the role of geological and climatic changes in the evolution of the IT region is currently available. After considering the key role of floristic regions in biogeography, we review the history of evolving concepts about the borders and composition of the IT region over the past 200 years and outline a tentative circumscription for it. We also summarise current knowledge on the geological and climatic history of the IT region. We then use this knowledge to generate specific evolutionary hypotheses to explain how different geological, palaeoclimatic, and ecological factors contributed to range expansion and contraction, thus shaping patterns of speciation in the IT region over time and space. Both historical and ecological biogeography should be applied to understand better the floristic diversification of the region. This will ultimately require evolutionary comparative analyses based on integrative phylogenetic, geological, climatic, ecological, and species distribution studies on the region. Furthermore, an understanding of evolutionary and ecological processes will play a major role in regional planning for protecting biodiversity of the IT region in facing climatic change. With this review, we aim to introduce the IT floristic region to a broader audience of evolutionary, ecological and systematic biologists, thus promoting cutting-edge research on this area and raising awareness of this vast and diverse, yet understudied, part of the world.