Nature Newsmaker of the Year is CERN’s Lyn Evans, the project director for the Large Hadron Collider. His year has seen a remarkable high, the much-heralded start-up of the LHC. And a notable low, when it broke down expensively, following a helium leak. Geoff Brumfiel profiles Evans and looks to the future of the new collider, which is to form the cornerstone of CERN’s particle physics research for the next two decades. (Cover photo: Maximilien Brice/CERN) [News Feature p. 862; Editorial p. 837; www.nature.com/podcast] In Research Highlights [page 840], Nature editors pick some of the outstanding papers of the year that we didn’t publish and in the extended Contents pages we select some of our favourites from Nature. Other year-end content in this double issue includes a selection of the most eye-catching images of the year [2008 Gallery p. 854], and a round-up of some of the medal- and prize-winners of 2008 [page 860]. The year-end content, with much more including videos and podcast highlights, can be found on www.nature.com/news/specials/2008/index.html.

Where next on Mars? Life after Phoenix The $420 million Phoenix lander project was a low-cost mission by the standards of space research, but its brief working life on Mars yielded spectacular results. It showed what NASA’s “faster, better, cheaper” principle of the 1990s could achieve, but it followed two high-profile failures — Mars Climate Orbiter burned up in the martian atmosphere in September 1999 and months later Mars Polar Lander failed during its descent. Landing successfully near the north pole on 25 May this year, Phoenix lander performed science on 149 sols (martian days) of its 152-sol life before the mission was officially declared over with martian winter closing in. In that time it took more than 25,000 pictures (including the cover image, taken on 'sol 2' of the lander’s life), performed chemistry on icy soil samples, recorded snow falling from overhead clouds, and photographed frost gathering on the ground. Eric Hand tells the story of a mission that almost didn’t happen and logs its scientific legacy.

Tumorigenic potential: A common attribute of human melanoma cells Cancer stem cells in human tumours have been defined in functional experiments as cells that are tumorigenic and self-renew when transplanted into immunocompromised mice. It has been shown for a number of tumour types that such cells are relatively rare. This has informed some approaches to therapy based on a ‘cancer stem cell model’, which targets these stem cells, rather than a whole tumour or cell population. New work suggests that for human melanomas at least, the cancer stem cell model may not apply. Rather, tumorigenic potential is a common attribute of melanoma cells. The experiments took melanoma cells from twelve patients, and using a xenotransplantation assay, found that about a quarter of the melanoma cells were tumour producing in mice. This suggests that a broad spectrum of cancer cells has the potential to contribute to tumour progression, and raises doubts over therapies specifically directed against small ‘cancer stem cell’ populations. The cover image depicts melanoma cells and tumours formed from such cells.

Sparkng a revolution: can plug in cars create the grid of the future? Sparking a revolution: Can lithium ion batteries power the car of the future? The appearance of affordable, rechargeable lithium-ion batteries in the 1990s revolutionized consumer electronics, first in video cameras and later in power tools, cell phones and of course laptop computers. The next generation of lithium-ion batteries — now emerging from the research labs — could have an even greater influence on the way we live. Imagine a world where today’s gas-guzzlers are replaced by millions of battery-powered cars plugged into a ‘green’ electricity grid. Effective lithium-ion batteries could even tip the balance in favour of an increased reliance on renewable electricity sources such as wind and solar power by providing a distributed electricity storage network. In a News Feature, Jeff Tollefson reports on the latest developments in and future prospects for lithium-battery technology and talks to the experts about when and whether electric cars will consign the internal combustion engine to motoring history.

Darwin 200: Beyond the origin February 2009 sees the 200th anniversary of the birth of Charles Robert Darwin and November 2009 the 150th anniversary of the publication of his great work, On the Origin of Species. In the intervening two centuries, no single scientist has matched Darwin’s impact on the sciences, politics, religion, philosophy and art. This issue of Nature [see Introduction page 295; Editorial, p. 281] brings together news, research and analysis of Darwin, his life, his science and his legacy. Darwin saw the eye — so complex and seemingly useless with any of its components part-formed — as an obstacle to the acceptance of natural selection. Today we know it as one of evolution’s crowning glories — celebrated with a fold-out pictorial feature [p. 304] and current research [p. 395] that refers right back to the ‘protoeyes’ hypothesized by Darwin. In later writings (Descent of Man ,1871), Darwin touched on a topic that still divides evolutionary biologists — group selection. Does natural selection work for individuals against the interests of the group? Or is such thinking a historical mistake? We report on the debate and why it is important [p. 296], and review a ‘landmark book’ on the superorgansims of the insect world, where the group looms large [p. 320]. Extinction comes with the evolutionary territory. But is it for ever? With the publication of the genome sequence of the long-gone woolly mammoth [pp. 387, 330], some researchers are even claiming that mammoths will one day be recreated [News Feature p. 310]. Biologists tend to see evolved living systems as finely tuned machines, prone to failure if one component is faulty. But, as Tanguy Chouard reveals, this is not what happens in the real world [News Feature p. 300]. Plenty for biologists to celebrate and plenty of places to do it: we have trawled the world for events commemorating Darwin’s life and works [p. 322] and trawled the publishers’ lists for books doing the same [Books & Arts p. 323]. Not quite everybody will be in celebratory mood. The scientists we spoke to mostly are [Commentary p, 317], but past celebrations have had to tread carefully [Essay p. 324]. The Darwin-related content from this issue — and extra online-only material — can be accessed via: www.nature.com/darwin. Cover graphic: Jonathan Williams

Illuminating camouflage: light-induced dopamine neurons help tadpoles disappear The balance between neurons expressing various neurotransmitters is thought to be set under genetic control during brain development. It’s a crucial step, enabling signalling among populations of neurons. A new study by Davide Dulcis and Nicholas Spitzer shows that natural stimuli can also regulate the class of transmitter expressed in the brain of postembryonic Xenopus tadpoles. Like endogenously dopaminergic neurons, neurons newly expressing dopamine drive a simple camouflage behaviour. The cover shows sibling tadpoles, one adapted to a dark background and the other to a white background. Natural light increases the number of dopaminergic neurons in the hypothalamus where this behaviour is controlled; dark exposure causes a decrease. This plasticity in the developing nervous system may have broad implications, and could be relevant to changes in cognitive states regulated by biogenic amines. Intriguingly, bright light therapy is used to treat patients with seasonal affective disorder, a type of depression linked to dysfunctional dopamine signalling. [Article p. 195; News & Views p. 177] (Cover photo: Norma Velazquez Ulloa, Armando de la Torre and Krista Todd.)

Your life in your hands: Instructions for the personal genome age As the number of humans with their genomes fully sequenced grows and direct-to-consumer gene profiling companies push the boundaries of medical genetics, the once fanciful idea that medical and other interventions can be tailored around an individual's personal genome begins to look plausible. Which raises the question: how do we use this wealth of information? This issue focuses on personal genomics and its consequences. In News Features we seek the 'missing heritability' that seems to limit the number of disease-linked genes being found [page 18], look at a technology that may drive next generation of DNA sequencing machines [page 23] and reflect on the surprise closure of a lab at the forefront of genomics research [page 26]. Commentaries discuss the problems of balancing an individual's rights to privacy with the maximization for public benefit [page 32] and the ethics of personal genome tests [page 34]. These matters are considered in the Editorial [page 1] and go to http://tinyurl.com/6clk2x to air your views in the Nature forum. See also News [pages 11 & 12] and download the podcast from www.nature.com/podcast. Cover graphic by Jay Taylor