Diversification dynamics of a common deep-sea octocoral family linked to the Paleocene-Eocene thermal maximum.

The deep-sea has experienced dramatic changes in physical and chemical variables in the geological past. However, little is known about how deep-sea species richness responded to such changes over time and space. Here, we studied the diversification dynamics of one of the most diverse octocorallian families inhabiting deep sea benthonic environments worldwide and sustaining highly diverse ecosystems, Primnoidae. A newly dated species-level phylogeny was constructed to infer their ancestral geographic locations and dispersal rates initially. Then, we tested whether their global and regional (the Southern Ocean) diversification dynamics were mediated by dispersal rate and abiotic factors as changes in ocean geochemistry. Finally, we tested whether primnoids showed changes in speciation and extinction at discrete time points. Our results suggested primnoids likely originated in the southwestern Pacific Ocean during the Lower Cretaceous âˆ¼112 Ma, with further dispersal after the physical separation of continental landmasses along the late Mesozoic and Cenozoic. Only the speciation rate of the Southern Ocean primnoids showed a significant correlation to ocean chemistry. Moreover, the Paleocene-Eocene thermal maximum marked a significant increase in the diversification of primnoids at global and regional scales. Our results provide new perspectives on the macroevolutionary and biogeographic patterns of an ecologically important benthic organism typically found in deep-sea environments.

Uniparental and biparental markers unravel invasion pathways, population admixture, and genetic structure in naturalized rainbow trout (Oncorhynchus mykiss).

The present study combined uniparental mtDNA and biparental SNPs to illuminate the invasion and colonization pathways of rainbow trout, Oncorhynchus mykiss, one of the world's most widespread invasive fishes, that has been intensively propagated in Chile, South America. The specific aims of the study were (i) to evaluate potential donor populations, which could be either from the species' native range in North America or from introduced populations in Europe, by comparing mtDNA D-loop/control region haplotypes; and (ii) to assess the factors that have shaped genetic diversity and contemporary genetic structure of rainbow trout populations introduced to Chile through SNP genotyping. The authors comprehensively sampled 24 sites in 12 basins ranging from the High Andean Plateau (Altiplano, 18° S) to northern Patagonia (41° S). Results of the mtDNA data of naturalized trout populations from rivers in the Altiplano (northern Chile) differed from those collected in central and southern Chile, suggesting an origin from North American hatcheries. Naturalized trout populations in central and southern Chile, on the contrary, shared haplotypes with specimens found in European hatcheries. The southern and central Chile populations also contained rare haplotypes, possibly indicating potential spread through aquaculture escapes. Results of the SNP analysis revealed higher allelic richness for trout sampled in sites influenced by commercial aquaculture than sites without commercial aquaculture, likely due to increased admixture between aquaculture broodstock and naturalized trout. The analysis further uncovered some complex patterns of divergent trout populations with low genetic diversity as well as increased relatedness between individuals from isolated sites, suggesting possible local populations. A comprehensive characterization of genetic diversity and structure of rainbow trout should help identify management areas that may augment socioeconomic benefits while preventing the spread and further impacts on biodiversity.

Detection of selection signatures in the genome of a farmed population of anadromous rainbow trout (Oncorhynchus mykiss).

Domestication processes and artificial selection are likely to leave signatures that can be detected at a molecular level in farmed rainbow trout (Oncorhynchus mykiss). These signatures of selection are genomic regions that contain functional genetic variants conferring a higher fitness to their bearers. We genotyped 749 rainbow trout from a commercial population using a rainbow trout Axiom 57 K SNP array panel and identified putative genomic regions under selection using the pcadapt, Composite Likelihood Ratio (CLR) and Integrated Haplotype Score (iHS) methods. After applying quality-control pipelines and statistical analyses, we detected 12, 96 and 16 SNPs putatively under selection, associated with 96, 781 and 115 candidate genes, respectively. Several of these candidate genes were associated with growth, early development, reproduction, behavior and immune system traits. In addition, some of the SNPs were found in interesting regions located in autosomal inversions on Omy05 and Omy20. These findings could represent a genome-wide map of selection signatures in farmed rainbow trout and could be important in explaining domestication and selection for genetic traits of commercial interest.

Invasive Chinook Salmon in Chile: Stakeholder Perceptions and Management Conflicts around a New Common-use Resource.

Since the last decade, the Chinook salmon has become an invasive species in southern Chilean rivers, affecting their environment and displacing native species due to predation and competition. The socioeconomic valuation of this species is complex, due to its high economic, touristic, and culinary value. The tourism industry and artisanal fishing groups see the salmon as a new common-use resource to be regulated. The Chilean regulatory framework, in turn, has made the presence, danger, and economic importance of the species invisible. This document analyzes the social construction of salmonids according to different interest groups and their interaction with the legal invisibility of this species. Our study delves into a particular group: the artisanal fishermen of La Barra del Toltén, in the Araucania Region, whose main economic activity has been illegal Chinook salmon fishing, pressing for their legalization. This case raises reflections on the perennially complex relationship between nature and society, as well as the management of common problems and common resources.

Southernmost distribution limit for endangered Peladillas (Aplochiton taeniatus) and non-native coho salmon (Oncorhynchus kisutch) coexisting within the Cape Horn biosphere reserve, Chile.

The Cape Horn Biosphere Reserve, one of the last wild areas of the planet, is not exempt from the pressures of global change, such as non-native species introductions. During 2018 and 2019 we studied the Róbalo river basin in order to update the diversity and distribution of fishes. Here, we report for the first time the native and endangered "Peladillas" Aplochiton taeniatus and the non-native coho salmon Oncorhynchus kisutch. The coexistence of native and non-native fishes poses a challenge for the management and conservation of aquatic biota from the Cape Horn Biosphere Reserve.

Hierarchical biogeographical processes largely explain the genomic divergence pattern in a species complex of sea anemones (Metridioidea: Sagartiidae: Anthothoe).

The phylogenetic resolution provided by genome-wide data has demonstrated the usefulness of RAD sequencing to tackle long-standing taxonomic questions. Cnidarians have recently become a model group in this regard, yet species delimitation analyses have been mostly performed in octocorals. In this study, we used RAD sequencing to test the species hypotheses in a wide-spread complex of sea anemones (genus Anthothoe), contrasting this new line of evidence with their current classification. The alternative hypotheses were tested using a Bayes Factors delimitation method, and the most probable species tree was then evaluated under different biogeographic scenarios. Our results decisively rejected the current morphology-informed delimitation model and infer the presence of several cryptic species associated with distinct marine ecoregions. This spatial pattern was remarkably consistent throughout the study, highlighting the role of geographic distribution as a powerful explanatory variable of lineages diversification. The southern Gondwana pattern with episodic, jump dispersal events is the biogeographic historical representation that best fits the Anthothoe species tree. The high population differentiation possibly amplified by the occurrence of asexual reproduction makes it difficult to identify genes responsible for local adaptation, however, these seem to be mainly associated with cellular and metabolic processes. We propose a new set of species hypotheses for the Southern Hemispheric Anthothoe clade, based on the pronounced genomic divergence observed among lineages. Although the link between the genetic and phenotypic differentiation remains elusive, newer sequencing technologies are bringing us closer to understanding the evolution of sea anemone diversity and, therefore, how to appropriately classify them.

Consumption of marine-derived nutrients from invasive Chinook salmon (Oncorhynchus tshawytscha) transfer ω-3 highly unsaturated fatty acids to invasive resident rainbow trout (O. mykiss).

Marine-derived nutrients (MDN) contained in gametes (mature eggs and sperm), carcasses and metabolic wastes from anadromous migratory salmon can transfer energy and materials to fresh water, thereby affecting the structure and function of stream ecosystems. This is crucial among ecosystems where humans have mediated biological invasions by propagating non-native species. Previous studies have demonstrated that consumption of MDN from salmon can benefit both native and invasive resident fishes. Yet, a more detailed understanding of the transfer of biomolecules with important physiological functions such as ω-3 highly unsaturated fatty acids (HUFAs) have received less attention among researchers. Here we demonstrate that consumption of MDN contained in invasive Chinook salmon eggs transfers ω-3 HUFAs (e.g., EPA and DHA) to resident invasive rainbow trout in a river food web. We conducted a field study in river sections previously identified as spawning areas for Chinook salmon in the Cisnes River, Patagonia. Rainbow trout were sampled around salmon spawning areas before, during, and after the salmon spawning season. Additionally, we collected tissue from different food web resources and components of different origin (e.g., primary producers, aquatic and terrestrial items) from the Cisnes River system. Analyses of stomach contents of trout were performed in conjunction with analyses of both lipid content and fatty acid profiles of trout tissue and food web components. Chinook salmon eggs showed higher content of ω-3 HUFAs, especially EPA (31.08 ± 23.08 mg g DW-1) and DHA (27.50 ± 14.11 mg g DW-1) than either freshwater or terrestrial components (0-6.10 mg g DW-1 both EPA and DHA). We detected marked shifts in the fatty acid profile (~six-fold increase in EPA and DHA) of trout following consumption of Chinook salmon eggs. Our findings suggest that MDN via consumption of salmon eggs by resident rainbow trout may positively influence resident trout and likely contribute to gauge synergistic interactions between invaders on receiving ecosystems of Patagonia.

Neutral and adaptive loci reveal fine-scale population structure in Eleginops maclovinus from north Patagonia.

Patagonia is an understudied area, especially when it comes to population genomic studies with relevance to fishery management. However, the dynamic and heterogeneous landscape in this area can harbor an important but cryptic genetic population structure. Once such information is revealed, it can be integrated into the management of infrequently investigated species. Eleginops maclovinus is a protandrous hermaphrodite species with economic importance for local communities that are currently managed as a single genetic unit. In this study, we sampled five locations distributed across a salinity cline from Northern Patagonia to investigate the genetic population structure of E. maclovinus. We used restriction site-associated DNA (RAD) sequencing and outlier tests to obtain neutral and adaptive loci, using FST and GEA approaches. We identified a spatial pattern of structuration with gene flow and spatial selection by environmental association. Neutral and adaptive loci showed two and three genetic groups, respectively. The effective population sizes estimated ranged from 572 (Chepu) to 14,454 (Chaitén) and were influenced more by locality than by salinity cline. We found loci putatively associated with salinity suggesting that salinity may act as a selective driver in E. maclovinus populations. These results suggest a complex interaction between genetic drift, gene flow, and natural selection in this area. Our findings also suggest several evolutionary significant units in this area, and the information should be integrated into the management of this species. We discussed the significance of these results for fishery management and suggest future directions to improve our understanding of how E. maclovinus has adapted to the dynamic waters of Northern Patagonia.

Single nucleotide polymorphisms unravel hierarchical divergence and signatures of selection among Alaskan sockeye salmon (Oncorhynchus nerka) populations.

BACKGROUND: Disentangling the roles of geography and ecology driving population divergence and distinguishing adaptive from neutral evolution at the molecular level have been common goals among evolutionary and conservation biologists. Using single nucleotide polymorphism (SNP) multilocus genotypes for 31 sockeye salmon (Oncorhynchus nerka) populations from the Kvichak River, Alaska, we assessed the relative roles of geography (discrete boundaries or continuous distance) and ecology (spawning habitat and timing) driving genetic divergence in this species at varying spatial scales within the drainage. We also evaluated two outlier detection methods to characterize candidate SNPs responding to environmental selection, emphasizing which mechanism(s) may maintain the genetic variation of outlier loci. RESULTS: For the entire drainage, Mantel tests suggested a greater role of geographic distance on population divergence than differences in spawn timing when each variable was correlated with pairwise genetic distances. Clustering and hierarchical analyses of molecular variance indicated that the largest genetic differentiation occurred between populations from distinct lakes or subdrainages. Within one population-rich lake, however, Mantel tests suggested a greater role of spawn timing than geographic distance on population divergence when each variable was correlated with pairwise genetic distances. Variable spawn timing among populations was linked to specific spawning habitats as revealed by principal coordinate analyses. We additionally identified two outlier SNPs located in the major histocompatibility complex (MHC) class II that appeared robust to violations of demographic assumptions from an initial pool of eight candidates for selection. CONCLUSIONS: First, our results suggest that geography and ecology have influenced genetic divergence between Alaskan sockeye salmon populations in a hierarchical manner depending on the spatial scale. Second, we found consistent evidence for diversifying selection in two loci located in the MHC class II by means of outlier detection methods; yet, alternative scenarios for the evolution of these loci were also evaluated. Both conclusions argue that historical contingency and contemporary adaptation have likely driven differentiation between Kvichak River sockeye salmon populations, as revealed by a suite of SNPs. Our findings highlight the need for conservation of complex population structure, because it provides resilience in the face of environmental change, both natural and anthropogenic.

Chilean Salmon Sushi: Genetics Reveals Product Mislabeling and a Lack of Reliable Information at the Point of Sale.

Species diagnosis is essential to assess the level of mislabeling or misnamed seafood products such as sushi. In Chile, sushi typically includes salmon as the main ingredient, but species used are rarely declared on the menu. In order to identify which species are included in the Chilean sushi market, we analyzed 84 individual sushi rolls sold as "salmon" from sushi outlets in ten cities across Chile. Using a polymerase chain reaction-restriction fragment length polymorphism protocol (PCR-RFLP), we identified mislabeled and misnamed products. Atlantic salmon was the most common salmonid fish used in sushi, followed by coho salmon, rainbow trout, and Chinook salmon. We found a total of 23% and 18% of the products were mislabeled and misnamed, respectively. In 64% of cases, the salesperson selling the product could not identify the species. We also identified the use of wild-captured Chinook salmon samples from a naturalized population. Our results provide a first indication regarding species composition in Chilean sushi, a quantification of mislabeling and the level of misinformation declared by sales people to consumers. Finally, considering that Chinook salmon likely originates from a non-licensed origin and that sushi is an uncooked product, proper identification in the food production chain may have important consequences for the health of consumers.

Whole genome re-sequencing reveals recent signatures of selection in three strains of farmed Nile tilapia (Oreochromis niloticus).

Nile tilapia belongs to the second most cultivated group of fish in the world, mainly because of its favorable characteristics for production. Genetic improvement programs and domestication process of Nile tilapia may have modified the genome through selective pressure, leaving signals that can be detected at the molecular level. In this work, signatures of selection were identified using genome-wide SNP data, by two haplotype-based (iHS and Rsb) and one FST based method. Whole-genome re-sequencing of 326 individuals from three strains (A, B and C) of farmed tilapia maintained in Brazil and Costa Rica was carried out using Illumina HiSeq 2500 technology. After applying conventional SNP-calling and quality-control filters, ~ 1.3 M high-quality SNPs were inferred and used as input for the iHS, Rsb and FST based methods. We detected several candidate genes putatively subjected to selection in each strain. A considerable number of these genes are associated with growth (e.g. NCAPG, KLF3, TBC1D1, TTN), early development (e.g. FGFR3, PFKFB3), and immunity traits (e.g. NLRC3, PIGR, MAP1S). These candidate genes represent putative genomic landmarks that could be associated to traits of biological and commercial interest in farmed Nile tilapia.

Interaction of landscape and life history attributes on genetic diversity, neutral divergence and gene flow in a pristine community of salmonids.

Landscape genetics holds promise for the forecasting of spatial patterns of genetic diversity based on key environmental features. Yet, the degree to which inferences based on single species can be extended to whole communities is not fully understood. We used a pristine and spatially structured community of three landlocked salmonids (Salvelinus fontinalis, Salmo salar, and Salvelinus alpinus) from Gros Morne National Park (Newfoundland, Canada) to test several predictions on the interacting effects of landscape and life history variation on genetic diversity, neutral divergence, and gene flow (m, migration rate). Landscape factors consistently influenced multispecies genetic patterns: (i) waterfalls created strong dichotomies in genetic diversity and divergence between populations above and below them in all three salmonids; (ii) contemporary m decreased with waterway distance in all three species, while neutral genetic divergence (theta) increased with waterway distance, albeit in only two taxa; (iii) river flow generally produced downstream-biased m between populations when waterfalls separated these, but not otherwise. In contrast, we expected differential life history to result in a hierarchy of neutral divergence (S. salar > S. fontinalis > S. alpinus) based on disparities in dispersal abilities and population size from previous mark-recapture studies. Such hierarchy additionally matched varying degrees of spatial genetic structure among species revealed through individual-based analyses. We conclude that, whereas key landscape attributes hold power to predict multispecies genetic patterns in equivalent communities, they are likely to interact with species-specific life history attributes such as dispersal, demography, and ecology, which will in turn affect holistic conservation strategies.

Phylogeography and Population Genetics of Vicugna vicugna: Evolution in the Arid Andean High Plateau.

The vicuña (Vicugna vicugna) is the most representative wild ungulate of the high Andes of South America with two recognized morphological subspecies, V. v. mensalis in the north and V. v. vicugna in the south of its distribution. Current vicuña population size (460,000-520,000 animals) is the result of population recovery programs established in response to 500 years of overexploitation. Despite the vicuña's ecosystemic, economic and social importance, studies about their genetic variation and history are limited and geographically restricted. Here, we present a comprehensive assessment of the genetic diversity of vicuña based on samples collected throughout its distribution range corresponding to eleven localities in Peru and five in Chile representing V. v. mensalis, plus four localities each in Argentina and Chile representing V. v. vicugna. Analysis of mitochondrial DNA and microsatellite markers show contrasting results regarding differentiation between the two vicuña types with mitochondrial haplotypes supporting subspecies differentiation, albeit with only a few mutational steps separating the two subspecies. In contrast, microsatellite markers show that vicuña genetic variation is best explained as an isolation by distance pattern where populations on opposite ends of the distribution present different allelic compositions, but the intermediate populations present a variety of alleles shared by both extreme forms. Demographic characterization of the species evidenced a simultaneous and strong reduction in the effective population size in all localities supporting the existence of a unique, large ancestral population (effective size ∼50,000 individuals) as recently as the mid-Holocene. Furthermore, the genetic variation observed across all localities is better explained by a model of gene flow interconnecting them rather than only by genetic drift. Consequently, we propose space "continuous" Management Units for vicuña as populations exhibit differentiation by distance and spatial autocorrelation linked to sex biased dispersal instead of population fragmentation or geographical barriers across the distribution.

Contrasting genetic metrics and patterns among naturalized rainbow trout (Oncorhynchus mykiss) in two Patagonian lakes differentially impacted by trout aquaculture.

Different pathways of propagation and dispersal of non-native species into new environments may have contrasting demographic and genetic impacts on established populations. Repeated introductions of rainbow trout (Oncorhynchus mykiss) to Chile in South America, initially through stocking and later through aquaculture escapes, provide a unique setting to contrast these two pathways. Using a panel of single nucleotide polymorphisms, we found contrasting genetic metrics and patterns among naturalized trout in Lake Llanquihue, Chile's largest producer of salmonid smolts for nearly 50 years, and Lake Todos Los Santos (TLS), a reference lake where aquaculture has been prohibited by law. Trout from Lake Llanquihue showed higher genetic diversity, weaker genetic structure, and larger estimates for the effective number of breeders (Nb) than trout from Lake TLS. Trout from Lake TLS were divergent from Lake Llanquihue and showed marked genetic structure and a significant isolation-by-distance pattern consistent with secondary contact between documented and undocumented stocking events in opposite shores of the lake. Multiple factors, including differences in propagule pressure, origin of donor populations, lake geomorphology, habitat quality or quantity, and life history, may help explain contrasting genetic metrics and patterns for trout between lakes. We contend that high propagule pressure from aquaculture may not only increase genetic diversity and Nb via demographic effects and admixture, but also may impact the evolution of genetic structure and increase gene flow, consistent with findings from artificially propagated salmonid populations in their native and naturalized ranges.

Genetic signals of artificial and natural dispersal linked to colonization of South America by non-native Chinook salmon (Oncorhynchus tshawytscha).

Genetics data have provided unprecedented insights into evolutionary aspects of colonization by non-native populations. Yet, our understanding of how artificial (human-mediated) and natural dispersal pathways of non-native individuals influence genetic metrics, evolution of genetic structure, and admixture remains elusive. We capitalize on the widespread colonization of Chinook salmon Oncorhynchus tshawytscha in South America, mediated by both dispersal pathways, to address these issues using data from a panel of polymorphic SNPs. First, genetic diversity and the number of effective breeders (Nb) were higher among artificial than natural populations. Contemporary gene flow was common between adjacent artificial and natural and adjacent natural populations, but uncommon between geographically distant populations. Second, genetic structure revealed four distinct clusters throughout the Chinook salmon distributional range with varying levels of genetic connectivity. Isolation by distance resulted from weak differentiation between adjacent artificial and natural and between natural populations, with strong differentiation between distant Pacific Ocean and Atlantic Ocean populations, which experienced strong genetic drift. Third, genetic mixture analyses revealed the presence of at least six donor geographic regions from North America, some of which likely hybridized as a result of multiple introductions. Relative propagule pressure or the proportion of Chinook salmon propagules introduced from various geographic regions according to government records significantly influenced genetic mixtures for two of three artificial populations. Our findings support a model of colonization in which high-diversity artificial populations established first; some of these populations exhibited significant admixture resulting from propagule pressure. Low-diversity natural populations were likely subsequently founded from a reduced number of individuals.

Temporal Genetic Variance and Propagule-Driven Genetic Structure Characterize Naturalized Rainbow Trout (Oncorhynchus mykiss) from a Patagonian Lake Impacted by Trout Farming.

Knowledge about the genetic underpinnings of invasions-a theme addressed by invasion genetics as a discipline-is still scarce amid well documented ecological impacts of non-native species on ecosystems of Patagonia in South America. One of the most invasive species in Patagonia's freshwater systems and elsewhere is rainbow trout (Oncorhynchus mykiss). This species was introduced to Chile during the early twentieth century for stocking and promoting recreational fishing; during the late twentieth century was reintroduced for farming purposes and is now naturalized. We used population- and individual-based inference from single nucleotide polymorphisms (SNPs) to illuminate three objectives related to the establishment and naturalization of Rainbow Trout in Lake Llanquihue. This lake has been intensively used for trout farming during the last three decades. Our results emanate from samples collected from five inlet streams over two seasons, winter and spring. First, we found that significant intra- population (temporal) genetic variance was greater than inter-population (spatial) genetic variance, downplaying the importance of spatial divergence during the process of naturalization. Allele frequency differences between cohorts, consistent with variation in fish length between spring and winter collections, might explain temporal genetic differences. Second, individual-based Bayesian clustering suggested that genetic structure within Lake Llanquihue was largely driven by putative farm propagules found at one single stream during spring, but not in winter. This suggests that farm broodstock might migrate upstream to breed during spring at that particular stream. It is unclear whether interbreeding has occurred between "pure" naturalized and farm trout in this and other streams. Third, estimates of the annual number of breeders (Nb) were below 73 in half of the collections, suggestive of genetically small and recently founded populations that might experience substantial genetic drift. Our results reinforce the notion that naturalized trout originated recently from a small yet genetically diverse source and that farm propagules might have played a significant role in the invasion of Rainbow Trout within a single lake with intensive trout farming. Our results also argue for proficient mitigation measures that include management of escapes and strategies to minimize unintentional releases from farm facilities.

Contemporary effective population and metapopulation size (N e and meta-N e): comparison among three salmonids inhabiting a fragmented system and differing in gene flow and its asymmetries.

We estimated local and metapopulation effective sizes ([Formula: see text] and meta-[Formula: see text]) for three coexisting salmonid species (Salmo salar, Salvelinus fontinalis, Salvelinus alpinus) inhabiting a freshwater system comprising seven interconnected lakes. First, we hypothesized that [Formula: see text] might be inversely related to within-species population divergence as reported in an earlier study (i.e., FST: S. salar> S. fontinalis> S. alpinus). Using the approximate Bayesian computation method implemented in ONeSAMP, we found significant differences in [Formula: see text] ([Formula: see text]) between species, consistent with a hierarchy of adult population sizes ([Formula: see text]). Using another method based on a measure of linkage disequilibrium (LDNE: [Formula: see text]), we found more finite [Formula: see text] values for S. salar than for the other two salmonids, in line with the results above that indicate that S. salar exhibits the lowest [Formula: see text] among the three species. Considering subpopulations as open to migration (i.e., removing putative immigrants) led to only marginal and non-significant changes in [Formula: see text], suggesting that migration may be at equilibrium between genetically similar sources. Second, we hypothesized that meta-[Formula: see text] might be significantly smaller than the sum of local [Formula: see text]s (null model) if gene flow is asymmetric, varies among subpopulations, and is driven by common landscape features such as waterfalls. One 'bottom-up' or numerical approach that explicitly incorporates variable and asymmetric migration rates showed this very pattern, while a number of analytical models provided meta-[Formula: see text] estimates that were not significantly different from the null model or from each other. Our study of three species inhabiting a shared environment highlights the importance and utility of differentiating species-specific and landscape effects, not only on dispersal but also in the demography of wild populations as assessed through local [Formula: see text]s and meta-[Formula: see text]s and their relevance in ecology, evolution and conservation.