BackgroundThe genetic origins of Uralic speakers from across a vast territory in the temperate zone of North Eurasia have remained elusive. Previous studies have shown contrasting proportions of Eastern and Western Eurasian ancestry in their mitochondrial and Y chromosomal gene pools. While the maternal lineages reflect by and large the geographic background of a given Uralic-speaking population, the frequency of Y chromosomes of Eastern Eurasian origin is distinctively high among European Uralic speakers. The autosomal variation of Uralic speakers, however, has not yet been studied comprehensively.ResultsHere, we present a genome-wide analysis of 15 Uralic-speaking populations which cover all main groups of the linguistic family. We show that contemporary Uralic speakers are genetically very similar to their local geographical neighbours. However, when studying relationships among geographically distant populations, we find that most of the Uralic speakers and some of their neighbours share a genetic component of possibly Siberian origin. Additionally, we show that most Uralic speakers share significantly more genomic segments identity-by-descent with each other than with geographically equidistant speakers of other languages. We find that correlated genome-wide genetic and lexical distances among Uralic speakers suggest co-dispersion of genes and languages. Yet, we do not find long-range genetic ties between Estonians and Hungarians with their linguistic sisters that would distinguish them from their non-Uralic-speaking neighbours.ConclusionsWe show that most Uralic speakers share a distinct ancestry component of likely Siberian origin, which suggests that the spread of Uralic languages involved at least some demic component.Electronic supplementary materialThe online version of this article (10.1186/s13059-018-1522-1) contains supplementary material, which is available to authorized users.

Quantitative phylogenetic methods have been used to study the evolutionary relationships and divergence times of biological species, and recently, these have also been applied to linguistic data to elucidate the evolutionary history of language families. In biology, the factors driving macroevolutionary processes are assumed to be either mainly biotic (the Red Queen model) or mainly abiotic (the Court Jester model) or a combination of both. The applicability of these models is assumed to depend on the temporal and spatial scale observed as biotic factors act on species divergence faster and in smaller spatial scale than the abiotic factors. Here, we used the Uralic language family to investigate whether both 'biotic' interactions (i.e. cultural interactions) and abiotic changes (i.e. climatic fluctuations) are also connected to language diversification. We estimated the times of divergence using Bayesian phylogenetics with a relaxed-clock method and related our results to climatic, historical and archaeological information. Our timing results paralleled the previous linguistic studies but suggested a later divergence of Finno-Ugric, Finnic and Saami languages. Some of the divergences co-occurred with climatic fluctuation and some with cultural interaction and migrations of populations. Thus, we suggest that both 'biotic' and abiotic factors contribute either directly or indirectly to the diversification of languages and that both models can be applied when studying language evolution.

O. 2001. Why does herbivore sex matter? Sexual differences in utilization of Fucus 6esiculosus by the isopod Idotea baltica. -Oikos 93: 77 -86.Optimal feeding is often constrained by predation avoidance, which may direct feeding to take place on more sheltered, but less profitable, parts of the habitat. Though constrained, feeding preferences and/or digestive capabilities should coevolve with the energetic and nutritional needs of the animal. These needs, as well as risk taking for these goals, may differ between the sexes. We studied sexual differences in the utilization of the brown alga Fucus 6esiculosus by the marine isopod Idotea baltica. In a feeding preference test with small pieces of alga both sexes prefer the apical, newly grown parts to the basal parts. However, males show stronger preference than females. When isopods are reared on the apical or basal part of the alga alone, sexes grow differently on these parts. Females gain weight equally well and their intermolt duration is the same on both parts of the alga, while males perform clearly worse on the basal than on the apical part. Despite the better quality of the apical parts of the alga, in a grazing experiment in a ''semi-natural'' environment with whole bushes of F. 6esiculosus also the basal parts are consumed, and even preferred over apical parts by females. We suggest that feeding preferences are subordinate to microhabitat choice, and therefore predation avoidance constrains optimal feeding. We hypothesize that the better ability of females than that of males to utilize the basal parts of the alga for growth is a co-adaptation to their risk-averse general reproductive strategy. We discuss the sexual differences in host plant utilization in the context of reproductive strategies of the sexes, especially different risk sensitivity of foraging, and its potential consequences on plant-herbivore interaction.

In diverse littoral communities, biotic interactions play an important role in community regulation. This article reviews how eutrophication modifies biotic interactions in littoral macroalgal communities. Eutrophication causes blooms of opportunistic algae, increases epibiotism, and affects regulation by grazers. Opportunistic algae and epibionts harm colonization and growth of perennial algae. Grazing regulates the density and species composition of macroalgal communities, especially at the early stage of algal colonization. Eutrophication supports higher grazer densities by increasing the availability and quality of algae to grazers. This may, on the one hand, enhance the capability of grazers to regulate and counteract the increase of harmful, bloom-forming macroalgae; on the other hand, it may increase grazing pressure on perennial species, with a poor tolerance of grazing. In highly eutrophic conditions, bloom-forming algae may also escape grazing control and accumulate. Increasing epibiotism and grazing threaten in particular the persistence of habitat-forming perennials such as the bladderwrack. An interesting property of biotic interactions is that they do not remain fixed but are able to evolve, as the traits of the interacting species adapt to each other and to abiotic conditions. The potential of plants and grazers to adapt is crucial to their chances to survive in changing environment.

Florence, was a brilliant Italian zoologist and ethologist, and one of the most well-known and active experts on alien aquatic species. Since her masters degree in Biology (1979) and her PhD in Animal Biology (Ethology) (1987), both obtained at the University of Florence, Francesca studied the behaviour and ecology of aquatic animals. Initially, most of her research concerned social recognition in crustaceans: she was particularly renowned for her studies on hermit crabs and crayfish, her principal model organisms.Then, from the 1990's onwards she worked in the field of invasion biology, her main interest until her death. Francesca devoted herself with enthusiasm and energy, not only to the problem of the invasive red swamp crayfish Procambarus clarkii, by revealing several aspects of its behavioral ecology, and by developing with her collaborators different methods for its control, but she gradually became an international expert on crayfish and more generally on aquatic alien species. In all aspects of her life, she was constantly driven by a continuous curiosity, thirst for knowledge and a will to face challenges; this was expressed by exploring and frequently opening new research fields. And she transmitted her drive and passion to the many students she supervised. One of the last papers with her contribution is published in this issue of Aquatic Invasions by Vera Gonçalves, her Portuguese PhD student working on the interaction between Procambarus clarkii and the zebra mussel Dreissena polymorpha, an issue of recent increasing interest in Francesca's team.