Publications by authors named "Bozo Frajman"

Article Synopsis
  • The Eurasian steppes are a vast and endangered ecosystem that has changed significantly between cold and warm periods, impacting the distribution of various species.
  • Researchers studied a specific group of plants, the Astragalus sect. Caprini, from northwestern Africa and Europe to understand their evolutionary history using genetic and morphological data.
  • Their findings suggest that these plants originated in the Irano-Turanian region and diversified mainly after the Mid-Pleistocene Transition, indicating that southern European mountains played a crucial role as refuges for species during climate changes.
View Article and Find Full Text PDF
Article Synopsis
  • - Deciduous forests in Europe were primarily found in small refuges during the cold Pleistocene periods, especially in southern and central regions, with significant refugia in the northwestern Balkan Peninsula.
  • - The study focused on the understorey species Euphorbia carniolica to understand historical forest dynamics, analyzing genetic and morphometric data across its entire range, revealing two main genetic groups linked to different refugia.
  • - Findings indicated that genetic separation between these groups began in the early Pleistocene, suggesting a broader historical distribution, and emphasized the late Pliocene origin of E. carniolica before the onset of colder periods in Eurasia.
View Article and Find Full Text PDF

High levels of phenotypic plasticity are thought to be inherently costly in stable or extreme environments, but enhanced plasticity may evolve as a response to new environments and foster novel phenotypes. Heliosperma pusillum forms glabrous alpine and pubescent montane ecotypes that diverged recurrently and polytopically (parallel evolution) and can serve as evolutionary replicates. The specific alpine and montane localities are characterized by distinct temperature conditions, available moisture, and light.

View Article and Find Full Text PDF

The Mediterranean Basin is renowned for its extremely rich biota and is considered as one of the 25 Global Biodiversity Hotspots, but its diversity is not homogeneously distributed. Outstanding in the number of (endemic) species are the Ligurian Alps (Italy). At the foot of the Ligurian Alps, little above the Mediterranean Sea, a disjunct occurrence of Italian endemic Euphorbia barrelieri was reported.

View Article and Find Full Text PDF

The interplay of polyploidisation, hybridization, and apomixis contributed to the exceptional diversity of (Rosaceae), giving rise to a mosaic of genetic and morphological entities. The species complex from the mountains of Central and South-eastern Europe represents an allopolyploid apomictic system of populations that originated following hybridisation between and . However, the mode and frequency of such allopolyploidisations and the relationships among different, morphologically more or less similar populations that have often been described as different taxa remain largely unexplored.

View Article and Find Full Text PDF

The Mediterranean Basin is one of the most biodiverse areas in the world, harboring 25,000 plant species, of which 60% are endemic. Some of them have narrow distributions, such as , which is only known from alpine screes on Mt. Parnassos in Greece.

View Article and Find Full Text PDF

Polyploidisation, agmatoploidy and symploidy have driven the diversification of sect. . Several morphologically very similar species with different karyotypes have evolved, but their evolutionary origins and relationships are unknown.

View Article and Find Full Text PDF

The Mediterranean Basin is an important biodiversity hotspot and one of the richest areas in the world in terms of plant diversity. Its flora parallels in several aspects that of the Eurasian steppes and the adjacent Irano-Turanian floristic region. The alliance spans this immense area from the western Mediterranean to Central Asia.

View Article and Find Full Text PDF

Genome size (GS) is an important characteristic that may be helpful in delimitation of taxa, and multiple studies have shown correlations between intraspecific GS variation and morphological or environmental factors, as well as its geographical segregation. We estimated a relative GS (RGS) of 707 individuals from 162 populations of with a geographic focus on the Balkan Peninsula, but also including several populations from the European Alps. is morphologically variable species thriving in various habitats and six subspecies have been recognized from the Balkan Peninsula.

View Article and Find Full Text PDF

The Balkan Peninsula played an important role in the evolution of many Mediterranean plants and served as a major source for post-Pleistocene colonisation of central and northern Europe. Its complex geo-climatic history and environmental heterogeneity significantly influenced spatiotemporal diversification and resulted in intricate phylogeographic patterns. To explore the evolutionary dynamics and phylogeographic patterns within the widespread eastern Mediterranean and central European species , we used a combination of phylogenomic (restriction-site associated DNA sequencing, RADseq) and phylogenetic (sequences of the plastid marker F) data as well as species distribution models generated for the present and the Last Glacial Maximum (LGM).

View Article and Find Full Text PDF

Understanding how organisms adapt to the environment is a major goal of modern biology. Parallel evolution-the independent evolution of similar phenotypes in different populations-provides a powerful framework to investigate the evolutionary potential of populations, the constraints of evolution, its repeatability and therefore its predictability. Here, we quantified the degree of gene expression and functional parallelism across replicated ecotype formation in Heliosperma pusillum (Caryophyllaceae), and gained insights into the architecture of adaptive traits.

View Article and Find Full Text PDF

Glacial refugia of alpine and subnival biota have been intensively studied in the European Alps but the fate of forests and their understory species in that area remains largely unclear. In order to fill this gap, we aimed at disentangling the spatiotemporal diversification of disjunctly distributed black hellebore (Ranunculaceae). We applied a set of phylogeographic analyses based on restriction-site associated DNA sequencing (RADseq) data and plastid DNA sequences to a range-wide sampling of populations.

View Article and Find Full Text PDF

The European steppes and their biota have been hypothesized to be either young remnants of the Pleistocene steppe belt or, alternatively, to represent relicts of long-term persisting populations; both scenarios directly bear on nature conservation priorities. Here, we evaluate the conservation value of threatened disjunct steppic grassland habitats in Europe in the context of the Eurasian steppe biome. We use genomic data and ecological niche modelling to assess pre-defined, biome-specific criteria for three plant and three arthropod species.

View Article and Find Full Text PDF
Article Synopsis
  • - The Eurasian steppes have been shaped by climatic changes from past ice ages, which influenced the evolutionary dynamics of plants like *Astragalus onobrychis*, a common steppe plant with various chromosome counts (diploid, tetraploid, octoploid).
  • - Through advanced genomic and genetic analysis, researchers discovered a complex evolutionary history for *A. onobrychis*, including events of polyploidy—specifically, an auto-tetraploidization and two allo-octoploidization instances likely involving genetic material from related species.
  • - The study identifies four main genetic clades within *A. onobrychis* that don't fully align with ploidy levels and suggests that their
View Article and Find Full Text PDF

The Andes are an important biogeographic region in South America extending for about 8000 km from Venezuela to Argentina. They are - along with the Patagonian steppes - the main distribution area of ca. 18 polyploid species of sect.

View Article and Find Full Text PDF

Next generation sequencing has revolutionised biology. Restriction-associated DNA sequencing (RADseq) has primarily been used to study infraspecific relationships but has also been applied in multi-species phylogenomic analyses. In this study, we used a combination of phylogenomic (with RADseq data) and phylogenetic (with sequences of the nuclear internal transcribed spacer, ITS) methods to explore relationships within the taxonomically intricate Euphorbia seguieriana s.

View Article and Find Full Text PDF

The mosaic distribution of interbreeding taxa with contrasting ecology and morphology offers an opportunity to study microevolutionary dynamics during ecological divergence. We investigate here the evolutionary history of an alpine and a montane ecotype of Heliosperma pusillum (Caryophyllaceae) in the south-eastern Alps. From six pairs of geographically close populations of the two ecotypes (120 individuals) we obtained a high-coverage restriction site associated DNA sequencing (RADseq) dataset that was used for demographic inference to test the hypothesis of parallel evolution of the two ecotypes.

View Article and Find Full Text PDF

Background: Polyploidy is one of the most important evolutionary pathways in flowering plants and has significantly contributed to their diversification and radiation. Due to the prevalence of reticulate evolution spanning three ploidy levels, Knautia is considered one of the taxonomically most intricate groups in the European flora. On the basis of ITS and plastid DNA sequences as well as AFLP fingerprints obtained from 381 populations of almost all species of the genus we asked the following questions.

View Article and Find Full Text PDF

Evolution is driven by natural selection, favouring individuals adapted in phenotypic traits to the environmental conditions at their growing site. To shed light on ecological and (epi-) genetically based differentiation between Heliosperma pusillum and Heliosperma veselskyi, two reciprocally non-monophyletic, but morphologically and ecologically divergent species from the south-eastern Alps, we studied various leaf anatomical traits and investigated chloroplast ultrastructure in leaves of the two species grown either in their natural habitat or in a common garden. The alpine H.

View Article and Find Full Text PDF

Premise Of The Study: Knautia drymeia is a morphologically variable, diploid and tetraploid temperate forest understory species distributed in southeastern Europe and adjacent areas. The species is an excellent system to explore the influence of polypoidy on taxonomic delineations, the role of hybridization among genetically distant populations in polyploid evolution, and the impact of glacial refugia on the evolution of polyploids.

Methods: Amplified fragment length polymorphism fingerprinting and multivariate analyses of morphological characters were performed on 57 populations spanning the distribution area of K.

View Article and Find Full Text PDF

Interspecific hybridization, especially when regularly followed by backcrossing (i.e., introgressive hybridization), conveys a substantial risk for many endangered organisms.

View Article and Find Full Text PDF

Background: Polyploidisation is one of the most important mechanisms in the evolution of angiosperms. As in many other genera, formation of polyploids has significantly contributed to diversification and radiation of Knautia (Caprifoliaceae, Dipsacoideae). Comprehensive studies of fine- and broad-scale patterns of ploidy and genome size (GS) variation are, however, still limited to relatively few genera and little is known about the geographic distribution of ploidy levels within these genera.

View Article and Find Full Text PDF

The Balkans are a major European biodiversity hotspot, however, almost nothing is known about processes of intraspecific diversification of the region's high-altitude biota and their reaction to the predicted global warming. To fill this gap, genome size measurements, AFLP fingerprints, plastid and nuclear sequences were employed to explore the phylogeography of Cerastium dinaricum. Range size changes under future climatic conditions were predicted by niche-based modeling.

View Article and Find Full Text PDF

The genus Knautia (Caprifoliaceae, Dipsacoideae) encompasses 40-60 species mainly distributed in western Eurasia, with highest species diversity in the Alps and the Balkan Peninsula. It is traditionally regarded as one of the taxonomically most challenging European genera due to the widespread occurrence of polyploidy, the high incidence of hybridisation and the maintenance of morphologically intermediate forms. A prerequisite for assessing the complex spatiotemporal diversification of a polyploid group is a comprehensive hypothesis of the phylogenetic relationships among its diploid members.

View Article and Find Full Text PDF