Systematics and Glacial Population History of the Alternifolium Group of the Flowering Plant Genus Chrysosplenium (Saxifragaceae)

The flowering plant genus Chrysosplenium comprises approximately 57 species of herbaceous perennials. These species are mainly distributed in the Northern Hemisphere where they occur in moist habitats. Though the center of diversity, and presumed location of origin, for the genus is east temperate Asia, more recently radiating taxa have invaded the arctic of North America and Europe. There are six species of Chrysosplenium in North America and four of them (i.e., C. iowense, C. tetrandrum, C. wrightii, and C. rosendahlii) belong to the section Alternifolia. Termed the Alternifolium group, this collection of species presents an excellent opportunity to study the evolution of variation in arctic and alpine environments. Similar to many arctic taxa, these species display very little morphologic or genetic variation, but they exhibit diversity in chromosome number, breeding system, geographic distribution, and ecology. Though the Alternifolium group has been the subject of numerous taxonomic studies, no thorough investigation of its evolutionary history has been conducted. This study used a combination of genetic and phenotypic data (e.g., DNA sequence, Inter-Simple Sequence Repeat, morphology) to determine the patterns of variation present within the Alternifolium group and then used these patterns to infer historical processes that might have contributed to them. Through the course of the study, however, it also became necessary to investigate the applicability of genetic estimates derived from different molecular markers and statistical methods. Appropriate comparisons among genetic estimates are critical to accurately interpret results and generate new predictions

A review on introduced Cichla spp. and emerging concerns

Peacock bass (Cichla spp.) originates from the Neotropical environments of Brazil and Venezuela but, through trade and smuggling for aquarium keeping, sport fishing and aquaculture, it is now an emerging concern. Yet, less is known for Cichla spp. distribution and its ability to invade new environments. Aimed to communicate on Cichla spp. ecology, biology and introduction schemes from Scopus, Web of Science, Google Scholar and also National Centre for Biotechnology Information, this review also contains management strategies for invading fish species. While Cichla spp. can displace native fish populations, this concern is explained using ecological functions, physiological demands, direct and secondary invasion, disease tolerance and parasite spillover. Briefly, Cichla spp. has rapid embryogenesis (72 h) and matures in short periods (11–12 months), giving it an advantage to colonize new environments. With a large appetite, this true piscivore gains territorial control over water bodies by making it their feeding and nursery grounds. Perceived as an emerging concern after becoming introduced, seal-off or sport fishing were used to manage Cichla spp. but, this practice is not sustainable for the entire ecosystem. Hence, we recommend bottom-up management that involves community participation because they interact with the fish and have knowledge about their environment

Online Appendix 1

Collection and locality information for sampled populations of six Populus species

Online Appendix 4

Per locus gene statistic estimates for Populus balsamifera and P. trichocarpa

Data from: Pleistocene speciation in the genus Populus (Salicaceae)

The macro-evolutionary consequences of recent climate change remain controversial and there is little paleobotanical or morphological evidence that Pleistocene (1.8-0.12 Ma) glacial cycles acted as drivers of speciation, especially among lineages with long generation times, such as trees. We combined genetic and ecogeographic data from two closely related North American tree species, Populus balsamifera and P. trichocarpa (Salicacaeae) to determine if their divergence coincided with and was possibly caused by Pleistocene climatic events. We analyzed 32 nuclear loci from individuals of P. balsamifera and P. trichocarpa to produce coalescent-based estimates of the divergence time between the two species. We coupled the coalescent analyses with paleodistribution models to assess the influence of climate change on species’ range. Further, measures of niche overlap were used to investigate patterns of ecological differentiation between species. We estimated the divergence date of P. balsamifera and P. trichocarpa at approximately 75 Ka, during the middle of the Wisconsin glaciation (115–12 Ka). Significance tests of niche overlap, in conjunction with genetic estimates of migration, suggested that speciation occurred in allopatry, possibly resulting from the environmental effects of Pleistocene glacial cycles. Our results indicate the divergence of keystone tree species, that have shaped community diversity in northern North American ecosystems, was recent and may have been a consequence of Pleistocene-era glaciation and climate change

Online Appendix 5

The predictive posterior p-values for summary statistics simulated in goodness-of-fit tests of Populus trichocarpa and P. balsamifera divergence models

Online Appendix 3

Multivariate similarity surface and most dissimilar variable plots from species distribution models of Populus balsamifera and P. trichocarpa. They indicate novel climate conditions in the past and the climate variable responsible

Online Appendix 2

Primer and nucleotide substitution information for 32 nuclear loci used in the genetic study of Populus trichocarpa and P. balsamifera

PoplarRefSNPData

SNP data used to develop Q and A matrices

John Hawkins, 6 Crescent, Bognor, Sussex, to James Edward Smith, Norwich, [Norfolk]

Corrections and criticisms regarding "Flora Graeca", including spelling of Maina and errors in habitats taken from [John] Sibthorp's journals. Declines Smith's request for a copy of the work; the trustees have already incurred a high responsibility by advancing £750 before any sheets were printed