Volume 519 Number 7542

Editorials

An array of problems p.129

Political interference in the selection process for the headquarters of the Square Kilometre Array should not go unchallenged.

doi: 10.1038/519129a

All in good time p.129

Stratigraphers have yet to decide whether the Anthropocene is a new unit of geological time.

doi: 10.1038/519129b

In the beginning p.130

As the first true science journal marks 350 years, we must defend scholarly pursuits.

doi: 10.1038/519130a

News

News Features

The human age p.144

Momentum is building to establish a new geological epoch that recognizes humanity's impact on the planet. But there is fierce debate behind the scenes.

doi: 10.1038/519144a

Wars without end p.148

The world is full of bloody conflicts that can drag on for decades. Some researchers are trying to find resolutions through complexity science.

doi: 10.1038/19148a

News & Views

Enceladus' hot springs p.162

The detection of silicon-rich particles originating from Saturn's moon Enceladus suggests that water–rock interactions are currently occurring inside it — the first evidence of ongoing hydrothermal activity beyond Earth. See Letter p.207

doi: 10.1038/519162a

Disarming Wnt p.163

The secreted enzyme Notum has been found to inhibit the Wnt signalling pathway through removal of a lipid that is linked to the Wnt protein and that is required for activation of Wnt receptor proteins. See Article p.187

doi: 10.1038/nature14208

Fitness tracking for adapting populations p.164

A method for tracking the descendants of hundreds of thousands of yeast cells in an evolving population reveals that thousands of individuals contribute to early increases in population-wide fitness. See Article p.181

doi: 10.1038/nature14207

How bacteria get spacers from invaders p.166

Bacteria use CRISPR–Cas systems to develop immunity to viruses. Details of how these systems select viral DNA fragments and integrate them into bacterial DNA to create a memory of invaders have now been reported. See Articles p.193 & p.199

doi: 10.1038/nature14204

Black carbon and atmospheric feedbacks p.167

Climate simulations show that interactions between particles of black carbon and convective and cloud processes in the atmosphere must be considered when assessing the full climatic effects of these light-absorbing particulates.

doi: 10.1038/519167a

The origin of terrestrial hearing p.168

A study of the African lungfish reveals that it has a rudimentary ability to detect pressure waves caused by sound. The finding expands our knowledge of how hearing evolved in early tetrapods, the first vertebrates to have limbs and digits.

doi: 10.1038/519168a

Perspective

Defining the Anthropocene p.171

Formal criteria must be met to define a new human-driven epoch; the geological evidence appears to do so, with 1610 and 1964 both likely to satisfy the requirements for the start of the Anthropocene.

doi: 10.1038/nature14258

Articles

Notum deacylates Wnt proteins to suppress signalling activity p.187

The biochemical activity of Notum as a carboxylesterase that removes an essential lipid moiety from Wnt proteins is uncovered; the interaction of Notum with glypicans is required to ensure localization at the cell surface, and Notum may provide a new target for therapeutic development in diseases with defective Wnt signalling.

doi: 10.1038/nature14259

Integrase-mediated spacer acquisition during CRISPR–Cas adaptive immunity p.193

The bacterial CRISPR/Cas system acquires short phage sequences known as spacers that integrate between CRISPR repeats and constitute a record of phage infection; this study shows that the Cas1–Cas2 complex is the minimal machinery required for spacer acquisition and the complex integrates oligonucleotide DNA substrates into acceptor DNA in a manner similar to retroviral integrases and DNA transposases with Cas 1 as the catalytic subunit and Cas2 acting to increase integration activity.

doi: 10.1038/nature14237

Cas9 specifies functional viral targets during CRISPR–Cas adaptation p.199

Bacterial CRISPR–Cas loci acquire short phage sequences called spacers that integrate between DNA repeats and how these viral sequences are chosen was unknown; in these studies of the type II CRISPR–Cas system of Streptococcus pyogenes, the Cas9 nuclease known to inactivate invading viral DNA was found to be required for the selection of functional spacers during CRISPR immunity.

doi: 10.1038/nature14245

Letters

Ongoing hydrothermal activities within Enceladus p.207

Analysis of silicon-rich, nanometre-sized dust particles near Saturn shows them to consist of silica, which was initially embedded in icy grains emitted from Enceladus’ subsurface waters and released by sputter erosion in Saturn’s E ring; their properties indicate their ongoing formation and transport by high-temperature hydrothermal reactions from the ocean floor and up into the plume of Enceladus.

doi: 10.1038/nature14262

Observation of antiferromagnetic correlations in the Hubbard model with ultracold atoms p.211

Ultracold atomic gases in optical lattices potentially offer simulations of condensed-matter phenomena beyond what theory and computations can access; compensated optical lattice techniques applied to the Hubbard model now enable unprecedented low temperatures to be reached for fermions — only 1.4 times that of the antiferromagnetic phase transition, approaching the limits of present modelling techniques.

doi: 10.1038/nature14223

Large-scale discovery of novel genetic causes of developmental disorders p.223

Up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis; here, in a systematic and nationwide study of 1,133 children with severe, undiagnosed developmental disorders, and their parents, exome sequencing and array-based detection of chromosomal rearrangements reveals novel genes causing developmental disorders, increasing the proportion of children that can now be diagnosed to 31%.

doi: 10.1038/nature14135

Orientation columns in the mouse superior colliculus p.229

Population recordings reveal that neurons in the mouse superior colliculus are grouped according to their preferred orientations or movement axes for visual line stimuli, similar to the columnar arrangement in visual cortex of higher mammals; this functional architecture suggests that the superior colliculus samples the visual world unevenly for stimulus orientations.

doi: 10.1038/nature14103

Mechanosensory interactions drive collective behaviour in Drosophila p.233

Collective behaviour in animal groups can improve individual perception and decision-making, but the neural mechanisms involved have been hard to access in classic models for these phenomena; here it is shown that Drosophila’s olfactory responses are enhanced in groups of flies, through mechanosensory neuron-dependent touch interactions.

doi: 10.1038/nature14024

Group 2 innate lymphoid cells promote beiging of white adipose tissue and limit obesity p.242

Group 2 innate lymphoid cells are shown to have a critical role in energy homeostasis by producing methionine-enkephalin peptides in response to interleukin 33, thus promoting the beiging of white adipose tissue; increased numbers of beige (also known as brown-like or brite) fat cells in white adipose tissue leads to increased energy expenditure and decreased adiposity.

doi: 10.1038/nature14115