Przewalski’s horses (PHs, Equus ferus ssp. przewalskii) were discovered in the Asian steppes in the 1870s and represent the last remaining true wild horses. PHs became extinct in the wild in the 1960s but survived in captivity, thanks to major conservation efforts. The current population is still endangered, with just 2,109 individuals, one-quarter of which are in Chinese and Mongolian reintroduction reserves. These horses descend from a founding population of 12 wild-caught PHs and possibly up to four domesticated individuals.

The deep sea is the world’s largest ecosystem, with high levels of biodiversity and many species that exhibit life-history characteristics that make them vulnerable to high levels of exploitation. Many fisheries in the deep sea have a track record of being unsustainable. In the northeast Atlantic, there has been a decline in the abundance of commercial fish species since deep-sea fishing commenced in the 1970s.

The emergence of infectious diseases with a broad host range can have a dramatic impact on entire communities and has become one of the main threats to biodiversity. Here, we report the simultaneous exploitation of entire communities of potential hosts with associated severe declines following invasion by a novel viral pathogen. We found two phylogenetically related, highly virulent viruses (genus Ranavirus, family Iridoviridae) causing mass mortality in multiple, diverse amphibian hosts in northern Spain, as well as a third, relatively avirulent virus.

Primary tropical forests are lost at an alarming rate, and much of the remaining forest is being degraded by selective logging. Yet, the impacts of logging on biodiversity remain poorly understood, in part due to the seemingly conflicting findings of case studies: about as many studies have reported increases in biodiversity after selective logging as have reported decreases. Consequently, meta-analytical studies that treat selective logging as a uniform land use tend to conclude that logging has negligible effects on biodiversity.

The indiscriminate disposal of plastic to the environment is of concern. Microscopic plastic litter (

The likelihood that continuing greenhouse-gas emissions will lead to an unmanageable degree of climate change has stimulated the search for planetary-scale technological solutions for reducing global warming (