Wild-type (left) and CRISPR/Cas9-induced vestigial mutant (right) of the emerging model crustacean Parhyale hawaiensis. The vestigial mutant lacks both the edge of the dorsal body wall and structures associated with proximal leg segments, suggesting that both of these tissues qualify as crustacean tissues that could share ancestry with insect wings.

See Clark-Hachtel & Tomoyasu

A comparison of the plant communities in two long-term grassland experiments (The BioDIV Experiment, Cedar Creek, Minnesota, United States — see picture — and the Jena Experiment, Jena, Germany) to those of related real-world sites shows that accounting for unrealistic experimental communities does not substantially change the conclusions commonly drawn from biodiversity–ecosystem functioning experiments.

See Jochum et al.

A comparison of Mexican cavefish shows that, in contrast to individuals from rivers, individuals from caves have evolved increased sensitivity of the innate and adaptive immune systems and reduced investment in the innate immune system in response to lower parasite diversity.

See Peuß et al.

The COVID-19 pandemic has led to a drastic global reduction in modern human activity. This ‘anthropause’ could enable unprecedented insights into human–wildlife interactions. While this photograph was taken in a deer park, it captures the promise of a research opportunity tragically afforded by the pandemic. The Greta Thunberg mural in the background serves as a reminder that urgent action is required to shape a sustainable future.

See Rutz et al.

A mixed breeding colony of California sea lions (Zalophus californianus) and northern fur seals (Callorhinus ursinus) on San Miguel Island, California.

See Peart et al.

A school of fish on a remote coral reef in the Indian Ocean. Biodiversity was found to be the primary driver of ecosystem functioning of coral-reef fishes. The positive biodiversity-ecosystem function relationships were robust to two human-caused stressors: climate change and invasive species.

See Benkwitt et al

The Moorish idol (Zanclus cornutus), pictured here at Lord Howe Island during the Reef Life Survey underwater monitoring, was among 335 fish species studied to understand changes in body size in response to temperature.

See Audzijonyte et al.

A sunrise silhouette of waterbuck on the Urema floodplain of Mozambique’s Gorongosa National Park. Gorongosa’s wildlife was devastated by civil war in the 1980s and 1990s, but has lately been flourishing under a pioneering rewilding programme. The recovery of waterbuck and other large herbivores has dramatically reduced the abundance of invasive shrubs, which suggests that restoring large mammal populations can revive lost ecosystem functions.

See Guyton et al.

Genetically distinct populations of urban lizards, such as male crested anoles (Anolis cristatellus) in Puerto Rico, provide an opportunity to understand rapid parallel evolution of complex thermal traits. A single non-synonymous polymorphism associated with heat tolerance plasticity may explain how these urban lizards can endure higher temperatures than populations in forests.

See Campbell-Staton et al.

Mounted specimen of Edaphosaurus boanerges, a pelycosaur synapsid, from the collections at the Museum of Comparative Zoology, Harvard University. Pelycosaurs are the most ancient forerunners of mammals; however, despite their bizarre sails, it is likely their backbones were relatively uniform in function, more similar to living lizards or salamanders than to mammals.

See Jones et al

Many arthropod morphological novelties originate as outgrowths of the body wall, and few are as spectacular as the helmets of treehoppers, such as the helicopter-like helmet of Bocydium globulare, depicted. However, comparative transcriptomics demonstrates that treehopper helmets evolved through co-option of the wing gene-regulatory network rather than through modification of the network of the body wall itself.

See Fisher et al.

A celebration of some of the extinct species that have featured in our pages since our launch. Top, left to right: Suskityrannus hazelae and Mansourasaurus shahinae; middle, left to right: Ingentia prima, Elasmotherium sibiricum, Caelestiventus hanseni, Inquicus fellatus and Chimerarachne yingi; bottom, left to right: an anurognathid pterosaur and Ursus spelaeus.