Volume 542 Number 7641

Editorials

News

News Features

News & Views

Pulsating ice sheet p.298

During the last ice age, huge numbers of icebergs were episodically discharged from an ice sheet that covered North America. Numerical modelling suggests that these events resulted from a conceptually simple feedback cycle. See Letter p.332

doi: 10.1038/542298a

An atypical switch for metabolism and ageing p.299

The enzyme S6K1 phosphorylates the enzyme glutamyl-prolyl tRNA synthetase to modulate metabolic activity and lifespan, revealing an atypical role for this synthetase as a target of a key metabolic signalling pathway. See Letter p.357

doi: 10.1038/nature21500

Keen insights from quinoa p.300

Technological advances have allowed scientists to sequence the complex quinoa genome. This highlights the ongoing expansion of genomics beyond major crops to other plants that have relevance for global food security. See Article p.307

doi: 10.1038/nature21495

Gut feeling for food choice p.302

One effect of weight-loss surgery is a change in food preferences. An analysis in rats shows that this is caused by altered nutrient signals in the intestine. These activate the vagus nerve to increase signalling in the brain by the neurotransmitter dopamine.

doi: 10.1038/nature21499

Oceans lose oxygen p.303

Oxygen is essential to most life in the ocean. An analysis shows that oxygen levels have declined by 2% in the global ocean over the past five decades, probably causing habitat loss for many fish and invertebrate species. See Letter p.335

doi: 10.1038/542303a

Catastrophe triggers diversification p.304

An analysis of more than 2,000 species of bird provides insight into how the animals' diverse beak shapes evolved, and points to a single rare event as a trigger for the rapid initial divergence of avian lineages. See Letter p.344

doi: 10.1038/nature21494

Articles

The genome of Chenopodium quinoa OPEN p.307

Constructing a reference genome for quinoa (Chenopodium quinoa) allows for genetic diversity during the evolution of sub-genomes in quinoa to be characterized and markers that may be used to develop sweet commercial varieties are identified.

doi: 10.1038/nature21370

Letters

Primordial helium entrained by the hottest mantle plumes p.340

Analysis of helium isotope ratios in volcanic hotspot lavas suggests that hotter, more buoyant plumes upwelling from the deep mantle entrain high-3He/4He material, unlike cooler, less buoyant plumes, implying the existence of a dense, relatively undisturbed primordial reservoir in the deep mantle.

doi: 10.1038/nature21023

Mega-evolutionary dynamics of the adaptive radiation of birds p.344

A study of more than 2,000 bird species shows that diversity in bill shape expands towards extreme morphologies early in avian evolution in a series of major jumps, before switching to a second phase in which bills repeatedly evolve similar shapes by subdividing increasingly tight regions of already occupied niche space.

doi: 10.1038/nature21074