Reviews & Analysis

A cell population in the neural plate border region of embryos of ascidians, the closest relatives of vertebrates, has properties similar to those of the neural crest cells and neuromesodermal cells of vertebrate embryos. The evolutionary origin of these multipotent cells may date back to the common ancestor of vertebrates and ascidians.

Long-term experimental evolution in brewer’s yeast reveals how the transition to simple multicellularity can drive ecological divergence and maintain diversity.

Climate warming is triggering a steady increase in the mean thermal optimum of plant communities. We show that this increase reflects the dieback of cold-adapted species rather than the arrival of warmer-adapted species, with negative effects on local diversity and mutually cancelling effects on community heterogeneity.

We evaluate the drivers of intensification traps — the combined loss of biodiversity and crop production that results from too-intensive agriculture. Our results reveal the conditions under which these lose–lose situations emerge and highlight the strong ramifications of disregarding biodiversity in agricultural management.

Using over 200 chromosomal genomes to reconstruct 250 million years of evolutionary history, we define the 32 linkage groups (Merian elements) that were present in the ancestor of Lepidoptera. We chart the dynamics of chromosome fusion and fission that accompanied the global diversification of Lepidoptera.

Efforts to monitor genetic diversity in populations vary greatly among European countries. The populations and species that are most likely to experience the greatest impacts of climate change are not well covered by these efforts, which suggests an urgent need for a substantial expansion in their monitoring.

Floristic homogenization — an increase in plant similarity within a given region — threatens biodiversity. By studying the taxonomic similarity of the floras of South Pacific islands over the past 5,000 years, we find that initial human settlement was probably a major driver of floristic homogenization.

Sequencing of a hagfish genome — one of the two jawless vertebrate lineages (cyclostomes) — constrains the timing and nature of genome duplication events that characterize early vertebrate evolution. Genome duplications occurred among ancestral vertebrates and cyclostomes, but genome-doubling in ancestral jawed vertebrates was caused by hybridization, which resulted in an unparalleled morphological diversification.

Data that span 15 generations reveal how gene flow and selection in a subordinate mesopredator are affected by pathogen-driven declines in the population density of a top predator. This work highlights the evolutionary impacts of interspecific competition and elucidates landscape-scale effects of an indirect interaction between a pathogen and nonhost species.

Humans are considered to be altricial (strongly underdeveloped at birth) with respect to other primates, but this observation is driven by the strong postnatal enlargement of human brains. We inferred that the developmental stage of human brains at birth does not differ substantially from that of other fossil hominins.

Microbiomes show dynamic compositions and behaviours. The prediction of microbiome dynamics over time has proven difficult. Now, in an open system with relatively controlled environmental constraints, it is possible to correctly predict the future composition and dynamics of a resident microbial community.

We examined the interactive effects of temperature and the presence of apex fish predators on food web structure in Icelandic geothermal streams. Fish suppressed the biomass of invertebrates and thus released algae from grazing pressure, but only at higher temperatures, which illustrates how the combination of warming and apex predators triggers this trophic cascade.

Fire activity and deforestation accelerated in Remote Oceania following human settlement. However, geoarchaeology and palaeoecology indicate that peak fire activity and grassland expansion primarily coincided with high frequencies of El Niño droughts, which suggests that there are complex relationships among human land use, fire and climate in the western Pacific.

Data from 5,525 in-water reef fish surveys conducted between 1- and 30-m depth reveal predictable depth-dependent zonation across the Pacific Ocean, particularly in the absence of a local human population. By contrast, relationships between depth and biomass were reduced or absent at populated islands, which suggests a human impact on depth-dependent ecological organization.

A defensive bacterial symbiont, spreading rapidly through populations of whitefly in nature, suppresses the proliferation, sporulation and transmission of a fungal pathogen in the whitefly. The pathogen is shown to be an important driving force for rapid shifts of the symbiont in the natural niche.

Using a mechanistic model based on neutral theory, we examined the effects of the ‘Carboniferous rainforest collapse’ on early tetrapod diversity. Our findings highlight the power of mechanistic models for decoding the fossil record and underscore the criticality of adjusting for sampling biases.

Analysis of an ocean basin-scale dataset revealed the existence of clear biogeographic provinces (deep and shallow abyssal zones) delimited by the carbonate compensation depth in Pacific Ocean seabed communities. Species diversity is maintained or increases with depth owing to phylum-level taxonomic replacements.

An analysis of millions of wildlife photographs has revealed that survival and colonization probabilities of mammals in protected areas are associated with people and what they do both inside and outside these areas.

Across taxa, increased temperature has been reported to generally reduce individual body size and change the body size structure of wild communities. Our research reveals that the effects of climate warming on the body size structure of stream fishes are also dependent on the intensity of other human pressures.

Efforts to document biodiversity have created large species datasets, but new research shows that field observations are biased towards particular regions, clades, traits and time periods, and do not accurately represent global biodiversity patterns. Although specimens are only infrequently preserved in natural history collections, they show relative congruence with expected biodiversity patterns and are vital for ecological research.