Volume 6 Issue 7, July 2022

Life emerged from and amidst non-living phenomena that already possessed some of the hallmarks now used four billion years later to recognize fossil organisms. It may be next to impossible to distinguish the earliest signs of life against this background. What can we still learn from fossil-like materials on the early Earth and elsewhere?

Humans have influenced global fire activity for millennia and will continue to do so into the future. Given the long-term interaction between humans and fire, we propose a collaborative research agenda linking archaeology and fire science that emphasizes the socioecological histories and consequences of anthropogenic fire in the development of fire management strategies today.

Analysis of sediment and pore water from three seagrass meadows around the world reveals an unexpected accumulation of labile carbon in the marine rhizosphere, explained by sediment chemistry.

Longitudinal data on gut microbiomes of wild baboons show that microbial communities are highly individualized, despite shared diet and environment within primate social groups.

Whole-genome sequencing and comparative omics analyses highlight recent and parallel paths to adaptive evolution involving expansions in zinc-binding proteins in the genomes of diverse cold-adapted algae.

Examining the evolutionary history of ungulate migration shows that this behaviour has evolved multiple times in response to grassland expansion and increased seasonality of resources.

As extremely large microbial community datasets have proliferated, numerous approaches to studying their ecological properties have emerged. In this Review, the authors offer a guide to five ecological modelling techniques used to study complex microbial communities.

Seagrass meadows are important carbon sinks. Here, the authors show that organic carbon in the form of simple sugars can accumulate at high concentrations in seagrass rhizospheres because plant phenolic compounds inhibit their consumption by microorganisms.

A dataset of 16 plant traits sampled from 2,461 individual trees from 74 tropical forest sites around the world is used to show a strong link between climate and plant functional diversity and redundancy, with drier tropical forests likely being less able to respond to declines in water availability.

A high-resolution map of the realized range limit of high-elevation trees across the Himalayas shows that trees are absent from the thermal treeline, determined by growing-season temperature, across the western and central Himalayas, as a result of human disturbance and/or premonsoon drought.

The authors link fungal diversity to the stability of terrestrial ecosystem productivity across three global datasets, finding that richness of decomposers and mycorrhizae are positively associated with stability while the richness of plant pathogens is negatively related to stability.

Genetic, ecological and simulation data demonstrate that the origin and coexistence of reproductively isolated sympatric groups in a fungus is driven by pleiotropic vegetative incompatibility genes under balancing selection.

Introgression is an important source of genetic variation. Analysing genomes of two sympatric widespread Asian oak species, the authors find introgression across the genome and signatures of adaptive introgression in regions with suppressed recombination rate.

A paleogenome from an approximately 100,000-year-old polar bear shows massive prehistoric, and largely unidirectional, gene flow from polar bears into brown bears at a time of climate change-induced overlap in the ranges of the two species. This admixture event cannot be detected using genomic data from living polar bears.

Social living has costs and benefits; here the authors use field studies, experiments and models to show that non-consumptive predation pressure in Trinidadian guppy shoals increases parasite transmission and selects for higher virulence.

Analysing gut microbial time series from wild baboons, the authors show that microbiome dynamics are rarely synchronized across hosts in shared environments but are highly individualized even within the same social groups.

Polar microalgae have high zinc demand. Here, the authors use quantitative proteomics and transcriptomics of polar and non-polar model algae combined with cellular physiology to show that zinc plays an important role in supporting photosynthetic growth in eukaryotic polar phytoplankton.

Using in vitro model communities and in vivo cystic fibrosis sputum samples, the authors show that interspecific competition undergoing in certain microbial communities can constrain the fixation of loss-of-function mutations in Pseudomonas aeruginosa quorum sensing, limiting the fixation of mutators.

Using data from 90 GPS-tagged black kites, the authors show that the ability to negotiate lateral drift is strongly selected over the course of the birds’ lifetimes, thereby shaping the abilities of the adult population.

The authors examine present and past drivers of ungulate migratory behaviour, finding that current migratory ungulates are larger, more grass-dependent and live at higher latitudes on average than non-migrants, and that migration probably emerged after the rise of C₄ grasslands and increased seasonality towards the poles.

Comparative genomics and proteomics of archaea and eukaryotes are used to explore the evolutionary history of eukaryotic chromatin, including modifications, catalytic functions and relationship with genomic parasites.

Genome-wide data of 16 ancient human individuals from islands of the North Moluccas, Sulawesi and East Nusa Tenggara reveal diverse sources of admixture and support a scenario of multiple dispersals into Wallacea.

This paper examines the main approaches for studying gene expression evolution, tests their inherent biases and discusses open questions about the evolution of the transcriptome.