A link between evolution and society fostering the UN sustainable development goals.

Given the multitude of challenges Earth is facing, sustainability science is of key importance to our continued existence. Evolution is the fundamental biological process underlying the origin of all biodiversity. This phylogenetic diversity fosters the resilience of ecosystems to environmental change, and provides numerous resources to society, and options for the future. Genetic diversity within species is also key to the ability of populations to evolve and adapt to environmental change. Yet, the value of evolutionary processes and the consequences of their impairment have not generally been considered in sustainability research. We argue that biological evolution is important for sustainability and that the concepts, theory, data, and methodological approaches used in evolutionary biology can, in crucial ways, contribute to achieving the UN Sustainable Development Goals (SDGs). We discuss how evolutionary principles are relevant to understanding, maintaining, and improving Nature Contributions to People (NCP) and how they contribute to the SDGs. We highlight specific applications of evolution, evolutionary theory, and evolutionary biology's diverse toolbox, grouped into four major routes through which evolution and evolutionary insights can impact sustainability. We argue that information on both within-species evolutionary potential and among-species phylogenetic diversity is necessary to predict population, community, and ecosystem responses to global change and to make informed decisions on sustainable production, health, and well-being. We provide examples of how evolutionary insights and the tools developed by evolutionary biology can not only inspire and enhance progress on the trajectory to sustainability, but also highlight some obstacles that hitherto seem to have impeded an efficient uptake of evolutionary insights in sustainability research and actions to sustain SDGs. We call for enhanced collaboration between sustainability science and evolutionary biology to understand how integrating these disciplines can help achieve the sustainable future envisioned by the UN SDGs.

Weak effect of urbanization on bdelloid rotifers living in lichens.

Human activities have an overwhelming impact on the natural environment, leading to a deep biodiversity crisis whose effects range from genes to ecosystems. Here, we analysed the effect of such anthropogenic impacts on bdelloid rotifers (Rotifera Bdelloidea), for whom these effects are poorly understood. We targeted bdelloid rotifers living in lichen patches across urbanization gradients in Flanders and Brussels (Belgium). Urbanization was measured as the percentage of built-up area (BU) across different spatial scales, at circles from 50 to 3200 m of radius around the lichen. Urbanization effects on biodiversity were assessed on abundance, species richness and community-weighted mean body size of bdelloid rotifers, as well as on genetic diversity of a mitochondrial marker (cytochrome c oxidase subunit I) of one of the most common and widespread bdelloid species, Adineta vaga. Overall, no negative effect of urbanization was found at any diversity level and any spatial scale. Counterintuitively, the BU area quantified at the largest spatial scale had a positive effect on abundance. These results leave open the question of whether negative effects of urbanization are present for bdelloid rotifers, if they are mediated by other unexplored drivers, or if such effects are only visible at even larger spatial scales.

Bacterioplankton Assembly Along a Eutrophication Gradient Is Mainly Structured by Environmental Filtering, Including Indirect Effects of Phytoplankton Composition.

Biotic interactions are suggested to be key factors structuring bacterioplankton community assembly but are rarely included in metacommunity studies. Eutrophication of ponds and lakes provides a useful opportunity to evaluate how bacterioplankton assembly is affected by specific environmental conditions, especially also by biotic interactions with other trophic levels such as phytoplankton and zooplankton. Here, we evaluated the importance of deterministic and stochastic processes on bacterioplankton community assembly in 35 shallow ponds along a eutrophication gradient in Belgium and assessed the direct and indirect effects of phytoplankton and zooplankton community variation on bacterioplankton assembly through a path analysis and network analysis. Environmental filtering by abiotic factors (suspended matter concentration and pH) explained the largest part of the bacterioplankton community variation. Phytoplankton community structure affected bacterioplankton structure through its effect on variation in chlorophyll-a and suspended matter concentration. Bacterioplankton communities were also spatially structured through pH. Overall, our results indicate that environmental variation is a key component driving bacterioplankton assembly along a eutrophication gradient and that indirect biotic interactions can also be important in explaining bacterioplankton community composition. Furthermore, eutrophication led to divergence in community structure and more eutrophic ponds had a higher diversity of bacteria.

Draft Genome Sequences of Five Carnobacterium sp. Strains Isolated from Freshwater Ponds in Belgium.

Strains belonging to the genus Carnobacterium are Gram-positive bacteria that are widely distributed in the environment. Here, we report the draft genome sequences of five Carnobacterium strains isolated from freshwater ponds located in Flanders, Belgium, and sequenced on an Illumina HiSeq 4000 platform.

Urbanization drives cross-taxon declines in abundance and diversity at multiple spatial scales.

The increasing urbanization process is hypothesized to drastically alter (semi-)natural environments with a concomitant major decline in species abundance and diversity. Yet, studies on this effect of urbanization, and the spatial scale at which it acts, are at present inconclusive due to the large heterogeneity in taxonomic groups and spatial scales at which this relationship has been investigated among studies. Comprehensive studies analysing this relationship across multiple animal groups and at multiple spatial scales are rare, hampering the assessment of how biodiversity generally responds to urbanization. We studied aquatic (cladocerans), limno-terrestrial (bdelloid rotifers) and terrestrial (butterflies, ground beetles, ground- and web spiders, macro-moths, orthopterans and snails) invertebrate groups using a hierarchical spatial design, wherein three local-scale (200 m × 200 m) urbanization levels were repeatedly sampled across three landscape-scale (3 km × 3 km) urbanization levels. We tested for local and landscape urbanization effects on abundance and species richness of each group, whereby total richness was partitioned into the average richness of local communities and the richness due to variation among local communities. Abundances of the terrestrial active dispersers declined in response to local urbanization, with reductions up to 85% for butterflies, while passive dispersers did not show any clear trend. Species richness also declined with increasing levels of urbanization, but responses were highly heterogeneous among the different groups with respect to the richness component and the spatial scale at which urbanization impacts richness. Depending on the group, species richness declined due to biotic homogenization and/or local species loss. This resulted in an overall decrease in total richness across groups in urban areas. These results provide strong support to the general negative impact of urbanization on abundance and species richness within habitat patches and highlight the importance of considering multiple spatial scales and taxa to assess the impacts of urbanization on biodiversity.

Freshwater Bacterioplankton Metacommunity Structure Along Urbanization Gradients in Belgium.

Urbanization is transforming and fragmenting natural environments worldwide, driving changes in biological communities through alterations in local environmental conditions as well as by changing the capacity of species to reach specific habitats. While the majority of earlier studies have been performed on higher plants and animals, it is crucial to increase our insight on microbial responses to urbanization across different spatial scales. Here, using a metacommunity approach, we evaluated the effects of urbanization on bacterioplankton communities in 50 shallow ponds in Belgium (Flanders region), one of the most urbanized areas in Northwest Europe. We estimated the relative importance of local environmental factors (35 abiotic and biotic variables), regional spatial factors and urbanization (built-up area) quantified at two spatial scales (200 m × 200 m and 3 km × 3 km). We show that urbanization at local or regional scales did not lead to strong changes in community composition and taxon diversity of bacterioplankton. Urbanization at regional scale (3 km × 3 km) explained only 2% of community composition variation while at local scale (200 m × 200 m), no effect was detected. Local environmental factors explained 13% (OTUs with relative abundance ≥ 0.1%) to 24% (12 dominant OTUs -≥ 1%) of community variation. Six local environmental variables significantly explained variation in bacterioplankton community composition: pH, alkalinity, conductivity, total phosphorus, abundance of Daphnia and concentration of copper (Cu), of which pH was partly mediated by urbanization. Our results indicate that environmental rather than spatial factors accounted for the variation in bacterioplankton community structure, suggesting that species sorting is the main process explaining bacterioplankton community assembly. Apparently, urbanization does not have a direct and strong effect on bacterioplankton metacommunity structure, probably due to the capacity of these organisms to adapt toward and colonize habitats with different environmental conditions and due to their fast adaptation and metabolic versatility. Thus, bacterioplankton communities inhabiting shallow ponds may be less affected by environmental conditions resulting from urbanization as compared to the impacts previously described for other taxa.

A polyphasic approach to the delimitation of diatom species: a case study for the genus Pinnularia (Bacillariophyta).

Diatoms are one of the most abundant and arguably the most species-rich group of protists. Diatom species delimitation has often been based exclusively on the recognition of morphological discontinuities without investigation of other lines of evidence. Even though DNA sequences and reproductive experiments have revealed several examples of (pseudo)cryptic diversity, our understanding of diatom species boundaries and diversity remains limited. The cosmopolitan pennate raphid diatom genus Pinnularia represents one of the most taxon-rich diatom genera. In this study, we focused on the delimitation of species in one of the major clades of the genus, the Pinnularia subgibba group, based on 105 strains from a worldwide origin. We compared genetic distances between the sequences of seven molecular markers and selected the most variable pair, the mitochondrial cox1 and nuclear encoded LSU rDNA, to formulate a primary hypothesis on the species limits using three single-locus automated species delimitation methods. We compared the DNA-based primary hypotheses with morphology and with other available lines of evidence. The results indicate that our data set comprised 15 species of the P. subgibba group. The vast majority of these taxa have an uncertain taxonomic identity, suggesting that several may be unknown to science and/or members of (pseudo)cryptic species complexes within the P. subgibba group.

Body-size shifts in aquatic and terrestrial urban communities.

Body size is intrinsically linked to metabolic rate and life-history traits, and is a crucial determinant of food webs and community dynamics1,2. The increased temperatures associated with the urban-heat-island effect result in increased metabolic costs and are expected to drive shifts to smaller body sizes 3 . Urban environments are, however, also characterized by substantial habitat fragmentation 4 , which favours mobile species. Here, using a replicated, spatially nested sampling design across ten animal taxonomic groups, we show that urban communities generally consist of smaller species. In addition, although we show urban warming for three habitat types and associated reduced community-weighted mean body sizes for four taxa, three taxa display a shift to larger species along the urbanization gradients. Our results show that the general trend towards smaller-sized species is overruled by filtering for larger species when there is positive covariation between size and dispersal, a process that can mitigate the low connectivity of ecological resources in urban settings 5 . We thus demonstrate that the urban-heat-island effect and urban habitat fragmentation are associated with contrasting community-level shifts in body size that critically depend on the association between body size and dispersal. Because body size determines the structure and dynamics of ecological networks 1 , such shifts may affect urban ecosystem function.

A comparative hierarchical analysis of bacterioplankton and biofilm metacommunity structure in an interconnected pond system.

It is unknown whether bacterioplankton and biofilm communities are structured by the same ecological processes, and whether they influence each other through continuous dispersal (known as mass effects). Using a hierarchical sampling approach we compared the relative importance of ecological processes structuring the dominant fraction (relative abundance ≥0.1%) of bacterioplankton and biofilm communities from three microhabitats (open water, Nuphar and Phragmites sites) at within- and among-pond scale in a set of 14 interconnected shallow ponds. Our results demonstrate that while bacterioplankton and biofilm communities are highly distinct, a similar hierarchy of ecological processes is acting on them. For both community types, most variation in community composition was determined by pond identity and environmental variables, with no effect of space. The highest ß-diversity within each community type was observed among ponds, while microhabitat type (Nuphar, Phragmites, open water) significantly influenced biofilm communities but not bacterioplankton. Mass effects among bacterioplankton and biofilm communities were not detected, as suggested by the absence of within-site covariation of biofilm and bacterioplankton communities. Both biofilm and plankton communities were thus highly structured by environmental factors (i.e., species sorting), with among-lake variation being more important than within-lake variation, whereas dispersal limitation and mass effects were not observed.

Inoculation history affects community composition in experimental freshwater bacterioplankton communities.

Priority effects occur when the arrival order of species or genotypes has a lasting effect on community or population structure. For freshwater bacteria, priority effects have been shown experimentally among individual species, but no experiments have been performed using complex natural communities. We investigated experimentally whether a foreign bacterioplankton community influences the community assembly trajectory when inoculated prior to the local community, whether inoculation time lag affects priority effects, and how the individual OTUs responded to time lag. Two bacterioplankton communities from dissimilar ponds were inoculated into one of the natural media with a time lag of 0, 12, 36 or 60 h, giving advantage in time to the foreign community. All three time lags resulted in priority effects, as the final community composition of these treatments differed significantly from that of the treatment with no time lag, but compositional shifts were not linear to inoculation time lag. The responses of individual OTUs to time lag were highly diverse and not predictable based on their immigration history or relative abundance in the inocula or control. The observed impact and complexity of priority effects in multispecies systems emphasize the importance of this process in structuring both natural and industrial bacterial communities.

Eco-evolutionary dynamics in urbanized landscapes: evolution, species sorting and the change in zooplankton body size along urbanization gradients.

Urbanization causes both changes in community composition and evolutionary responses, but most studies focus on these responses in isolation. We performed an integrated analysis assessing the relative contribution of intra- and interspecific trait turnover to the observed change in zooplankton community body size in 83 cladoceran communities along urbanization gradients quantified at seven spatial scales (50-3200 m radii). We also performed a quantitative genetic analysis on 12 Daphnia magna populations along the same urbanization gradient. Body size in zooplankton communities generally declined with increasing urbanization, but the opposite was observed for communities dominated by large species. The contribution of intraspecific trait variation to community body size turnover with urbanization strongly varied with the spatial scale considered, and was highest for communities dominated by large cladoceran species and at intermediate spatial scales. Genotypic size at maturity was smaller for urban than for rural D. magna populations and for animals cultured at 24°C compared with 20°C. While local genetic adaptation likely contributed to the persistence of D. magna in the urban heat islands, buffering for the phenotypic shift to larger body sizes with increasing urbanization, community body size turnover was mainly driven by non-genetic intraspecific trait change.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'.

Ocean plankton. Determinants of community structure in the global plankton interactome.

Species interaction networks are shaped by abiotic and biotic factors. Here, as part of the Tara Oceans project, we studied the photic zone interactome using environmental factors and organismal abundance profiles and found that environmental factors are incomplete predictors of community structure. We found associations across plankton functional types and phylogenetic groups to be nonrandomly distributed on the network and driven by both local and global patterns. We identified interactions among grazers, primary producers, viruses, and (mainly parasitic) symbionts and validated network-generated hypotheses using microscopy to confirm symbiotic relationships. We have thus provided a resource to support further research on ocean food webs and integrating biological components into ocean models.

Environmental rather than spatial factors structure bacterioplankton communities in shallow lakes along a > 6000 km latitudinal gradient in South America.

Metacommunity studies on lake bacterioplankton indicate the importance of environmental factors in structuring communities. Yet most of these studies cover relatively small spatial scales. We assessed the relative importance of environmental and spatial factors in shaping bacterioplankton communities across a > 6000 km latitudinal range, studying 48 shallow lowland lakes in the tropical, tropicali (isothermal subzone of the tropics) and tundra climate regions of South America using denaturing gradient gel electrophoresis. Bacterioplankton community composition (BCC) differed significantly across regions. Although a large fraction of the variation in BCC remained unexplained, the results supported a consistent significant contribution of local environmental variables and to a lesser extent spatial variables, irrespective of spatial scale. Upon correction for space, mainly biotic environmental factors significantly explained the variation in BCC. The abundance of pelagic cladocerans remained particularly significant, suggesting grazer effects on bacterioplankton communities in the studied lakes. These results confirm that bacterioplankton communities are predominantly structured by environmental factors, even over a large-scale latitudinal gradient (6026 km), and stress the importance of including biotic variables in studies that aim to understand patterns in BCC.

Effects of dietary arabinoxylan-oligosaccharides (AXOS) and endogenous probiotics on the growth performance, non-specific immunity and gut microbiota of juvenile Siberian sturgeon (Acipenser baerii).

We investigated the effects of administration of putative endogenous probiotics Lactococcus lactis spp. lactis or Bacillus circulans, alone and in combination with arabinoxylan-oligosaccharides (AXOS), a new class of candidate prebiotics, in juvenile Siberian sturgeon (Acipenser baerii). Eight experimental diets were tested: basal diet (Diet 1), basal diet supplemented with 2% AXOS (Diet 2), or L. lactis ST G81 (Diet 3), L. lactis ST G45 (Diet 4), B. circulans ST M53 (Diet 5), L. lactis ST G81 + 2% AXOS (Diet 6), L. lactis ST G45 + 2% AXOS (Diet 7), B. circulans ST M53 + 2% AXOS (Diet 8). After four weeks, growth performance and feed conversion ratio significantly improved in fish fed diet 7. Innate immune responses of fish were boosted with both AXOS and probiotic diets, however synergistic effects of AXOS and probiotic diets were only observed for phagocytic and alternative complement activity. Phagocytic and respiratory burst activity of fish macrophage increased in fish fed diet 2 and 7, while humoral immune responses only increased in fish fed diet 7. Pyrosequencing analysis (16S rDNA) of the hindgut microbiota demonstrated that AXOS improved the colonization or/and growth capacity of L. lactis, as a higher relative abundance of L. lactis was observed in fish receiving diet 7. However, no observable colonization of B. circulans was found in the hindgut of fish fed diet 5 or 8, containing this bacterium. The dietary L. lactis ST G45 + 2% AXOS caused significant alterations in the intestinal microbiota by significantly decreasing in bacterial diversity, demonstrated by the fall in richness and Shannon diversity, and improved growth performance and boosted immune responses of Siberian sturgeon.

Prebiotic effects of arabinoxylan oligosaccharides on juvenile Siberian sturgeon (Acipenser baerii) with emphasis on the modulation of the gut microbiota using 454 pyrosequencing.

The potential of a novel class of prebiotics, arabinoxylan oligosaccharides (AXOS), was investigated on growth performance and gut microbiota of juvenile Acipenser baerii. Two independent feeding trials of 10 or 12 weeks were performed with basal diets supplemented with 2% or 4% AXOS-32-0.30 (trial 1) and 2% AXOS-32-0.30 or AXOS-3-0.25 (trial 2), respectively. Growth performance was improved by feeding 2% AXOS-32-0.30 in both trials, although not significantly. Microbial community profiles were determined using 454-pyrosequencing with barcoded primers targeting the V3 region of the 16S rRNA gene. AXOS significantly affected the relative abundance of bacteria at the phylum, family, genus and species level. The consumption of 2% AXOS-32-0.30 increased the relative abundance of Eubacteriaceae, Clostridiaceae, Streptococcaceae and Lactobacillaceae, while the abundance of Bacillaceae was greater in response to 4% AXOS-32-0.30 and 2% AXOS-3-0.25. The abundance of Lactobacillus spp. and Lactococcus lactis was greater after 2% AXOS-32-0.30 intake. Redundancy analysis showed a distinct and significant clustering of the gut microbiota of individuals consuming an AXOS diet. In both trials, concentration of acetate, butyrate and total short-chain fatty acids (SCFAs) increased in fish fed 2% AXOS-32-0.30. Our data demonstrate a shift in the hindgut microbiome of fish consuming different preparation of AXOS, with potential application as prebiotics.

Molecular evidence for distinct Antarctic lineages in the cosmopolitan terrestrial diatoms Pinnularia borealis and Hantzschia amphioxys.

Recent morphology-based studies indicate that freshwater diatom floras in the Antarctic comprise a significant share of endemics among a majority of apparently cosmopolitan species. Given the widespread (pseudo)cryptic species diversity in diatoms, we assessed the molecular divergence and temperature-dependent growth characteristics between Antarctic and non-Antarctic strains for two presumed species with a cosmopolitan distribution, namely Pinnularia borealis and Hantzschia amphioxys. Molecular phylogenies based on the plastid gene rbcL and the nuclear 28S rDNA (D1-D3 region) revealed that both taxa consist of multiple lineages, each including a distinct Antarctic lineage. A molecular clock estimates the origin of P. borealis at 35.8 (30-47) million years (Ma) ago, making this the oldest known diatom species complex. The Antarctic P. borealis lineage is estimated to have diverged 7.8 (2-15) Ma ago, after the geographical and thermal isolation of the Antarctic continent. Despite not being psychrophilic, the Antarctic lineages of P. borealis and H. amphioxys have a lower optimal growth temperature and upper lethal temperature than most lineages from more temperate regions, indicating niche differentiation. Together, this suggests that many presumed cosmopolitan Antarctic diatom species are in fact species complexes, possibly containing Antarctic endemics with low temperature preferences.

Effects of arabinoxylan-oligosaccharides (AXOS) on juvenile Siberian sturgeon (Acipenser baerii) performance, immune responses and gastrointestinal microbial community.

Arabinoxylan-oligosaccharides (AXOS) are a newly discovered class of candidate prebiotics that exert different properties depending on their structure. In this study the effects of two different structures of AXOS, namely AXOS-32-0.30 (average degree of polymerization: 32, average degree of substitution: 0.30) and AXOS-3-0.25, were investigated on growth performance, immune responses, gut microbial fermentation and gut bacterial composition of juvenile Siberian sturgeon (Acipenser baerii). After a two weeks acclimation, fish (25.9 ± 0.9 g) were distributed over 24 aquariums (8 replicates per treatment) and fed a control diet or a diet containing 2% AXOS-32-0.30 or AXOS-3-0.25 for 12 weeks. Growth performance and feed utilization tend to improve in sturgeon fed on diets supplemented with AXOS-32-0.30, however not significant. Survival was high in all groups. Both AXOS preparations significantly enhanced the phagocytic activity of fish macrophages compared to the control group, while the alternative haemolytic complement activity and total serum peroxidase content improved only in the group fed AXOS-32-0.30 (P < 0.05). The lysozyme activity was not affected by AXOS addition. Simultaneously, the amount of short-chain fatty acids (SCFAs) was highest in the hind gut of sturgeon fed AXOS-32-0.30. The concentrations of acetate, butyrate and total SCFAs in fish fed AXOS-32-0.30 was significantly higher than in the groups fed the control diet or AXOS-3-0.25. Study of the bacterial community in the sturgeon hindgut using PCR-denaturing gradient gel electrophoresis (PCR-DGGE) revealed that both preparations of AXOS induced changes in the bacterial composition. According to redundancy analysis (RDA), hindgut microbiota of each treatment group clustered apart from one another (P = 0.001). DNA sequencing of the dominant DGGE bands recovered from the different treatments showed that AXOS mainly stimulated the growth of lactic acid bacteria and Clostridium sp., with more pronounced effects of AXOS-32-0.30. It is concluded that AXOS improves sturgeon health through prebiotic action, but the induced effects depend on the specific structure of AXOS. A higher degree of polymerization of AXOS had a stronger beneficial impact in this sturgeon species.

Analysis of the microbial community structure in a membrane bioreactor during initial stages of filtration.

Membrane biofouling was investigated during the early stages of filtration in a laboratory-scale membrane bioreactor operated on molasses wastewater. The bacterial diversity and composition of the membrane biofilm and activated sludge were analyzed using terminal restriction fragment length polymorphism coupled with 16S rRNA clone library construction and sequencing. The amount of extracellular polymeric substances produced by bacteria was investigated using spectroscopic methods. The results reveal that the bacterial community of activated sludge differs significantly from that of the membrane biofilm, especially at the initial phase. Phylogenetic analysis based on 16S rRNA gene sequences identified 25 pioneer OTUs responsible for membrane surface colonization. Also, the relationship between the identified bacterial strains and the system specifications was explored.

A time-calibrated multi-gene phylogeny of the diatom genus Pinnularia.

Pinnularia is an ecologically important and species-rich genus of freshwater diatoms (Bacillariophyceae) showing considerable variation in frustule morphology. Interspecific evolutionary relationships were inferred for 36 Pinnularia taxa using a five-locus dataset. A range of fossil taxa, including newly discovered Middle Eocene forms of Pinnularia, was used to calibrate a relaxed molecular clock analysis and investigate temporal aspects of the genus' diversification. The multi-gene approach resulted in a well-resolved phylogeny of three major clades and several subclades that were frequently, but not universally, delimited by valve morphology. The genus Caloneis was not recovered as monophyletic, confirming that, as currently delimited, this genus is not evolutionarily meaningful and should be merged with Pinnularia. The Pinnularia-Caloneis complex is estimated to have diverged between the Upper Cretaceous and the early Eocene, implying a ghost range of at least 10 million year (Ma) in the fossil record.