Fires in Australia show the devastating interaction between climate and biodiversity emergencies, and make clear that action is needed at all levels.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

This year will see the finalization of a global framework for biodiversity for the next decade and beyond. We look at the reasons to be optimistic and call for increased engagement in the process.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A new study strengthens the evidence base for declining trends in insect abundance, but also adds some much-needed nuance to the apocalyptic narrative.

Prevailing models of sex-chromosome evolution were largely inspired by the stable and highly differentiated XY pairs of model organisms, such as those of mammals and flies. Recent work has uncovered an incredible diversity of sex-determining systems, bringing some of the assumptions of these traditional models into question. One particular question that has arisen is what drives some sex chromosomes to be maintained over millions of years and differentiate fully, while others are replaced by new sex-determining chromosomes before differentiation has occurred. Here, I review recent data on the variability of sex-determining genes and sex chromosomes in different non-model vertebrates and invertebrates, and discuss some theoretical models that have been put forward to account for this diversity.

Among mammals, placental invasion is correlated with vulnerability to malignancy. Animals with more invasive placentation (for example, humans) are more vulnerable to malignancy. To explain this correlation, we propose the hypothesis of ‘Evolved Levels of Invasibility’ proposing that the evolution of invasibility of stromal tissue affects both placental and cancer invasion. We provide evidence for this using an in vitro model. We find that bovine endometrial and skin fibroblasts are more resistant to invasion than are their human counterparts. Gene expression profiling identified genes with high expression in human but not in bovine fibroblasts. Knocking down a subset of them in human fibroblasts leads to stronger resistance to cancer cell invasion. Identifying the evolutionary determinants of stromal invasibility can provide important insights to develop rational antimetastatic therapeutics.

Males and females often differ in their fitness optima for shared traits that have a shared genetic basis, leading to sexual conflict. Morphologically differentiated sex chromosomes can resolve this conflict and protect sexually antagonistic variation, but they accumulate deleterious mutations. However, how sexual conflict is resolved in species that lack differentiated sex chromosomes is largely unknown. Here we present a chromosome-anchored genome assembly for rainbow trout (Oncorhynchus mykiss) and characterize a 55-Mb double-inversion supergene that mediates sex-specific migratory tendency through sex-dependent dominance reversal, an alternative mechanism for resolving sexual conflict. The double inversion contains key photosensory, circadian rhythm, adiposity and sex-related genes and displays a latitudinal frequency cline, indicating environmentally dependent selection. Our results show sex-dependent dominance reversal across a large autosomal supergene, a mechanism for sexual conflict resolution capable of protecting sexually antagonistic variation while avoiding the homozygous lethality and deleterious mutations associated with typical heteromorphic sex chromosomes.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Private-sector capital is needed to scale-up forest and landscape restoration initiatives globally. To ensure the delivery of social and environmental restoration objectives, investors need to be matched appropriately to different types of restoration projects, while policies need to realign investment incentives away from degradation-driving activities.