Evolution in small steps and giant leaps

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. hybridisation, whole-genome duplication). Despite this, a comprehensive review of plant invasion genomics has been lacking. Here, we aim to address this gap, highlighting recent discoveries that have helped progress the field. For example, by leveraging genomics in natural and experimental populations, botanical research has confirmed the importance of large-effect standing variation during adaptation in invasive species. Further, genomic investigations of plants are increasingly revealing that large structural variants, as well as genetic changes induced by whole-genome duplication such as genomic redundancy or the breakdown of dosage-sensitive reproductive barriers, can play an important role during adaptive evolution of invaders. However, numerous questions remain, including when chromosomal inversions might help or hinder invasions, whether adaptive gene reuse is common during invasions, and whether epigenetically induced mutations can underpin the adaptive evolution of plasticity in invasive populations. We conclude by highlighting these and other outstanding questions that genomic studies of invasive plants are poised to help answer.

Life history in Caenorhabditis elegans: from molecular genetics to evolutionary ecology

Life history is defined by traits that reflect key components of fitness, especially those relating to reproduction and survival. Research in life history seeks to unravel the relationships among these traits and understand how life history strategies evolve to maximize fitness. As such, life history research integrates the study of the genetic and developmental mechanisms underlying trait determination with the evolutionary and ecological context of Darwinian fitness. As a leading model organism for molecular and developmental genetics, Caenorhabditis elegans is unmatched in the characterization of life history-related processes, including developmental timing and plasticity, reproductive behaviors, sex determination, stress tolerance, and aging. Building on recent studies of natural populations and ecology, the combination of C. elegans' historical research strengths with new insights into trait variation now positions it as a uniquely valuable model for life history research. In this review, we summarize the contributions of C. elegans and related species to life history and its evolution. We begin by reviewing the key characteristics of C. elegans life history, with an emphasis on its distinctive reproductive strategies and notable life cycle plasticity. Next, we explore intraspecific variation in life history traits and its underlying genetic architecture. Finally, we provide an overview of how C. elegans has guided research on major life history transitions both within the genus Caenorhabditis and across the broader phylum Nematoda. While C. elegans is relatively new to life history research, significant progress has been made by leveraging its distinctive biological traits, establishing it as a highly cross-disciplinary system for life history studies.

Evolution: Unearthing missing links in the origin of our planet's primary carbon-fixing enzyme

Form I rubisco underpins life on Earth, but the origins of its anomalous and highly complex multimeric structure have long proven elusive. New research helps to unravel this enigma by uncovering key missing links in the enzyme's evolutionary history.

Chasing the mechanisms of ecologically adaptive salinity tolerance

Plants adapted to challenging environments offer fascinating models of evolutionary change. Importantly, they also give information to meet our pressing need to develop resilient, low-input crops. With mounting environmental fluctuation-including temperature, rainfall, and soil salinity and degradation-this is more urgent than ever. Happily, solutions are hiding in plain sight: the adaptive mechanisms from natural adapted populations, once understood, can then be leveraged. Much recent insight has come from the study of salinity, a widespread factor limiting productivity, with estimates of 20% of all cultivated lands affected. This is an expanding problem, given increasing climate volatility, rising sea levels, and poor irrigation practices. We therefore highlight recent benchmark studies of ecologically adaptive salt tolerance in plants, assessing macro- and microevolutionary mechanisms, and the recently recognized role of ploidy and the microbiome on salinity adaptation. We synthesize insight specifically on naturally evolved adaptive salt-tolerance mechanisms, as these works move substantially beyond traditional mutant or knockout studies, to show how evolution can nimbly "tweak" plant physiology to optimize function. We then point to future directions to advance this field that intersect evolutionary biology, abiotic-stress tolerance, breeding, and molecular plant physiology.

The evolutionary tuning of hearing

After the transition to life on land, tympanic middle ears emerged separately in different groups of tetrapods, facilitating the efficient detection of airborne sounds and paving the way for high frequency sensitivity. The processes that brought about high-frequency hearing in mammals are tightly linked to the accumulation of coding sequence changes in inner ear genes; many of which were selected during evolution. These include proteins involved in hair bundle morphology, mechanotransduction and high endolymphatic potential, somatic electromotility for sound amplification, ribbon synapses for high-fidelity transmission of sound stimuli, and efferent synapses for the modulation of sound amplification. Here, we review the molecular evolutionary processes behind auditory functional innovation. Overall, the evidence to date supports the hypothesis that changes in inner ear proteins were central to the fine tuning of mammalian hearing.

The problem of interaction

As we look to the next 75 years, I recount how the sociopolitical milieu in which the Society for the Study of Evolution (SSE) and the journal Evolution were formed in 1947 was a "problem of interaction."