Mangrove floristics and biogeography revisited: further deductions from biodiversity hot spots, ancestral discontinuities and common evolutionary processes

This treatment provides a novel re-assessment of the common biodiversity patterns and evolution of mangrove plants based on the ancestral biogeography, extant floristics and distribution records for all species. It is generally acknowledged that mangrove plants occur where they do in the world because past and current factors have influenced their dispersal, diversification and establishment. Over time, the importance and timing of each factor responsible will have changed notably, especially considering their likely co-occurrence with global processes including continental drift and periods of glacial maxima. The premise here is that all extant taxa arose concurrently from their 17 or so family lineages in response to the same overall influencing factors. Accordingly, the combined distribution and phylogenetic patterns of all mangrove genotypes therefore might have a broadly, common framework for their genesis and dispersal. In this treatment, I test the hypothesis that the evolutionary processes of diversification, divergence and speciation have been driven by largely similar geophysical circumstances and events of isolation and reunion. As such, all phylogenies might have been created from the same chief factors and events, including: land barriers, water separation, and climatic conditions; albeit applied sometimes differently for each of the genetic lineages where mutation rates and dispersal capacities might differ. With such matters in mind, the approach taken has been to thoroughly review known distributional records and patterns, along with assessments of diversity hotspots, spanning large geographic areas, plus species gradients and discontinuities of extant and fossil records. All these are considered tangible evidence of the processes of dispersal and evolution affecting particular mangrove entities. In this way, the combined influence of dispersal, divergence and speciation of the various mangrove plant types, as likely to be the key factors affecting phenotypic variations resulting in their possible, shared patterns around the world. In summary, the integrated role and influence of each taxon has been re-evaluated by comparing matching distributional patterns and common phylogenetic relationships in consideration of key drivers, concurrent physical events and circumstances

Landscape Genomics: Understanding Relationships Between Environmental Heterogeneity and Genomic Characteristics of Populations

Landscape genomics is a rapidly advancing research field that combines population genomics, landscape ecology, and spatial analytical techniques to explicitly quantify the effects of environmental heterogeneity on neutral and adaptive genetic variation and underlying processes. Landscape genomics has tremendous potential for addressing fundamental and applied research questions in various research fields, including ecology, evolution, and conservation biology. However, the unique combination of different scientific disciplines and analytical approaches also constitute a challenge to most researchers wishing to apply landscape genomics. Here, we present an introductory overview of important concepts and methods used in current landscape genomics. For this, we first define the field and explain basic concepts and methods to capture different hypotheses of landscape influences on neutral genetic variation. Next, we highlight established and emerging genomic tools for quantifying adaptive genetic variation in landscape genomic studies. To illustrate the covered topics and to demonstrate the potential of landscape genomics, we provide empirical examples addressing a variety of research question, i.e., the investigation of evolutionary processes driving population differentiation, the landscape genomics of range expanding species, and landscape genomic patterns in organisms of special interest, including species inhabiting aquatic and terrestrial environments. We conclude by outlining remaining challenges and future research avenues in landscape genomics