Copy number variation contributes to parallel local adaptation in an invasive plant.

Adaptation is a critical determinant of the diversification, persistence, and geographic range limits of species. Yet the genetic basis of adaptation is often unknown and potentially underpinned by a wide range of mutational types-from single nucleotide changes to large-scale alterations of chromosome structure. Copy number variation (CNV) is thought to be an important source of adaptive genetic variation, as indicated by decades of candidate gene studies that point to CNVs underlying rapid adaptation to strong selective pressures.

Rapid Parallel Adaptation in Distinct Invasions of Ambrosia Artemisiifolia Is Driven by Large-Effect Structural Variants.

When introduced to multiple distinct ranges, invasive species provide a compelling natural experiment for understanding the repeatability of adaptation. Ambrosia artemisiifolia is an invasive, noxious weed, and chief cause of hay fever. Leveraging over 400 whole-genome sequences spanning the native-range in North America and 2 invasions in Europe and Australia, we inferred demographically distinct invasion histories on each continent.

The genomic secrets of invasive plants.

Genomics has revolutionised the study of invasive species, allowing evolutionary biologists to dissect mechanisms of invasion in unprecedented detail. Botanical research has played an important role in these advances, driving much of what we currently know about key determinants of invasion success (e.g.

The genetic architecture of repeated local adaptation to climate in distantly related plants.

Closely related species often use the same genes to adapt to similar environments. However, we know little about why such genes possess increased adaptive potential and whether this is conserved across deeper evolutionary lineages. Adaptation to climate presents a natural laboratory to test these ideas, as even distantly related species must contend with similar stresses.

Does urbanisation lead to parallel demographic shifts across the world in a cosmopolitan plant?

Urbanisation is occurring globally, leading to dramatic environmental changes that are altering the ecology and evolution of species. In particular, the expansion of human infrastructure and the loss and fragmentation of natural habitats in cities is predicted to increase genetic drift and reduce gene flow by reducing the size and connectivity of populations. Alternatively, the 'urban facilitation model' suggests that some species will have greater gene flow into and within cities leading to higher diversity and lower differentiation in urban populations.

Temperature and sex shape reproductive barriers in a climate change hotspot.

Climate change is altering species ranges and reproductive interactions in existing ranges, offering species new scope to mate and hybridize. The outcomes will depend on how environmental factors shape reproductive barriers across life stages, yet this is rarely assessed across the environments that species encounter in nature. We assess prezygotic and postzygotic barriers, and their dependence on temperature and parental sex, in species of a reef-building tubeworm (Galeolaria) from a fast-warming biodiversity hotspot in southern Australia.

Assessing the invasive potential of different source populations of ragweed ( L.) through genomically informed species distribution modelling.

The genetic composition of founding populations is likely to play a key role in determining invasion success. Individual genotypes may differ in habitat preference and environmental tolerance, so their ability to colonize novel environments can be highly variable. Despite the importance of genetic variation on invasion success, its influence on the potential distribution of invaders is rarely investigated.

Genomic Tools in Biological Invasions: Current State and Future Frontiers.

Human activities are accelerating rates of biological invasions and climate-driven range expansions globally, yet we understand little of how genomic processes facilitate the invasion process. Although most of the literature has focused on underlying phenotypic correlates of invasiveness, advances in genomic technologies are showing a strong link between genomic variation and invasion success. Here, we consider the ability of genomic tools and technologies to (i) inform mechanistic understanding of biological invasions and (ii) solve real-world issues in predicting and managing biological invasions.

Haplotype-Resolved, Chromosome-Level Assembly of White Clover (Trifolium repens L., Fabaceae).

White clover (Trifolium repens L.; Fabaceae) is an important forage and cover crop in agricultural pastures around the world and is increasingly used in evolutionary ecology and genetics to understand the genetic basis of adaptation. Historically, improvements in white clover breeding practices and assessments of genetic variation in nature have been hampered by a lack of high-quality genomic resources for this species, owing in part to its high heterozygosity and allotetraploid hybrid origin.

Genome assembly of an Australian native grass species reveals a recent whole-genome duplication and biased gene retention of genes involved in stress response.

Background: The adaptive significance of polyploidy has been extensively debated, and chromosome-level genome assemblies of polyploids can provide insight into this. The Australian grass Bothriochloa decipiens belongs to the BCD clade, a group with a complex history of hybridization and polyploid. This is the first genome assembly and annotation of a species that belongs to this fascinating yet complex group.

Large haploblocks underlie rapid adaptation in the invasive weed Ambrosia artemisiifolia.

Adaptation is the central feature and leading explanation for the evolutionary diversification of life. Adaptation is also notoriously difficult to study in nature, owing to its complexity and logistically prohibitive timescale. Here, we leverage extensive contemporary and historical collections of Ambrosia artemisiifolia-an aggressively invasive weed and primary cause of pollen-induced hayfever-to track the phenotypic and genetic causes of recent local adaptation across its native and invasive ranges in North America and Europe, respectively.

Climate adaptation and vulnerability of foundation species in a global change hotspot.

Climate change is altering species ranges, and relative abundances within ranges, as populations become differentially adapted and vulnerable to the climates they face. Understanding present species ranges, whether species harbour and exchange adaptive variants, and how variants are distributed across landscapes undergoing rapid change, is therefore crucial to predicting responses to future climates and informing conservation strategies. Such insights are nonetheless lacking for most species of conservation concern.

Quantitative trait loci mapping reveals an oligogenic architecture of a rapidly adapting trait during the European invasion of common ragweed.

Biological invasions offer a unique opportunity to investigate evolution over contemporary timescales. Rapid adaptation to local climates during range expansion can be a major determinant of invasion success, yet fundamental questions remain about its genetic basis. This study sought to investigate the genetic basis of climate adaptation in invasive common ragweed ().

Uncovering the genomic basis of an extraordinary plant invasion.

Invasive species are a key driver of the global biodiversity crisis, but the drivers of invasiveness, including the role of pathogens, remain debated. We investigated the genomic basis of invasiveness in (common ragweed), introduced to Europe in the late 19th century, by resequencing 655 ragweed genomes, including 308 herbarium specimens collected up to 190 years ago. In invasive European populations, we found selection signatures in defense genes and lower prevalence of disease-inducing plant pathogens.

Pollen competition in hybridizing Cakile species: How does a latecomer win the race?

Premise: Hybridization between cross-compatible species depends on the extent of competition between alternative mates. Even if stigmatic compatibility allows for hybridization, hybridization requires the heterospecific pollen to be competitive. Here, we determined whether conspecific pollen has an advantage in the race to fertilize ovules and the potential handicap to be overcome by heterospecific pollen in invasive Cakile species.

Global urban environmental change drives adaptation in white clover.

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors.

Local adaptation and spatiotemporal patterns of genetic diversity revealed by repeated sampling of Caenorhabditis elegans across the Hawaiian Islands.

The nematode Caenorhabditis elegans is among the most widely studied organisms, but relatively little is known about its natural ecology. Genetic diversity is low across much of the globe but high in the Hawaiian Islands and across the Pacific Rim. To characterize the niche and genetic diversity of C.

Allen Orr and the genetics of adaptation.

Over most of the 20th century, evolutionary biologists predominantly subscribed to a strong form of "micro-mutationism," in which adaptive phenotypic divergence arises from allele frequency changes at many loci, each with a small effect on the phenotype. To be sure, there were well-known examples of large-effect alleles contributing to adaptation, yet such cases were generally regarded as atypical and unrepresentative of evolutionary change in general. In 1998, Allen Orr published a landmark theoretical paper in Evolution, which showed that both small- and large-effect mutations are likely to contribute to "adaptive walks" of a population to an optimum.

Genetically Based Trait Differentiation but Lack of Trade-offs between Stress Tolerance and Performance in Introduced Canada Thistle.

Trade-offs between performance and tolerance of abiotic and biotic stress have been proposed to explain both the success of invasive species and frequently observed size differences between native and introduced populations. Canada thistle seeds collected from across the introduced North American and the native European range were grown in benign and stressful conditions (nutrient stress, shading, simulated herbivory, drought, and mowing), to evaluate whether native and introduced individuals differ in performance or stress tolerance. An additional experiment assessed the strength of maternal effects by comparing plants derived from field-collected seeds with those derived from clones grown in the glasshouse.

The tip of the iceberg: Genome wide marker analysis reveals hidden hybridization during invasion.

Biological invasions are accelerating, and invasive species can have large economic impacts as well as severe consequences for biodiversity. During invasions, species can interact, potentially resulting in hybridization. Here, we examined two Cakile species, C.

Parallel flowering time clines in native and introduced ragweed populations are likely due to adaptation.

As introduced species expand their ranges, they often encounter differences in climate which are often correlated with geography. For introduced species, encountering a geographically variable climate sometimes leads to the re-establishment of clines seen in the native range. However, clines can also be caused by neutral processes, and so it is important to gather additional evidence that population differentiation is the result of selection as opposed to nonadaptive processes.