Understanding the genome
The sequencing of the 6 billion chemical “letters” of human DNA was completed in draft in 2000 and in final form in 2003. But clinical benefits have arrived more slowly than the initial hype suggested. This is mainly because the human genome actually works in a much more complex way than predicted by the late-20th-century model.
Twenty-first-century research shows that we have only 21,000 genes, one-fifth of the number predicted when the project started, and that just 1.5 per cent of the genome consists of conventional protein-coding genes. Efforts are under way to understand the vital regulatory and other functions of the non-coding regions of the genome, once dismissed wrongly as “junk DNA”.
Extra planets – and extraterrestrials?
Astronomers have long theorised that many of the billions of stars in our galaxy must have orbiting planets. Since 1995 they have been finding these “exoplanets” at an increasing rate although those identified so far are much larger than Earth. More excitement will come with the discovery of Earth-like planets in Earth-like orbits around Sun-like stars, because of the possibility of extraterrestrial life. The next generation of space observatories should be able to examine these planets’ atmospheres for the spectroscopic signatures of molecules produced by biological processes. There is even the remote chance that radiotelescopes may pick up signals from an extraterrestrial civilisation.
The composition of the cosmos
Cosmologists are still coming to terms with the surprising 1998 discovery that mysterious “dark energy” is accelerating the expansion of the universe. Astronomers calculate that dark energy makes up 74 per cent of the universe but they have no idea what it is. The marginally less mysterious “dark matter” makes up 22 per cent – leaving just 4 per cent for all the ordinary matter in the objects we can see directly. Dark matter is probably made of massive particles, which interact so little with ordinary matter that instruments have been unable to detect them. But the subatomic debris from smashing atoms together at Cern’s Large Hadron Collider may offer a chance of identification in the future.
Leap for quantum computing
Quantum computing offers the possibility of a radical transition: a fundamentally different way of processing data. Prototype devices are beginning to emerge around the world. Last year, a team at Bristol University made a photonic chip that processes data according to the counter-intuitive rules of quantum physics, rather than conventional electronics. Because quantum particles can influence one another at a distance (“entanglement”) and be in several places at the same time (“superposition”), they could in principle perform parallel calculations far beyond the capability of today’s supercomputers. Governments and companies are investing hundreds of millions of dollars but formidable technical barriers must be overcome.
Graphene, the ‘wonder material’
Graphene, first made in 2004 and recognised by last year’s Nobel physics prize, is the “wonder material” of the 21st century. Andre Geim and Konstantin Novoselov succeeded in laying down two-dimensional carbon sheets just a single atom thick, which have astonishing physical and electronic properties.
The superlatives are endless. Graphene has astonishing strength and the best heat and electricity conductivity of any known material. Hundreds of research teams are competing to investigate its use for everything from transistors to memory chips. But some people worry that the field is over-hyped, with insufficient attention paid to the difficulties of manufacturing devices in commercial quantities.
Embryonic stem cells and regenerative medicine
The field of regenerative medicine was ignited by the discovery in 1998 that “pluripotent” stem cells, capable in principle of becoming any type of specialised cell from brain to blood, could be grown from early human embryos. Despite opposition from some religious groups, embryonic stem cells have progressed into early clinical trials.
Meanwhile some scientific attention has switched to an alternative way of producing embryo-like stem cells. These induced pluripotent stem cells, or iPSCs, are made by treating adult cells, usually from skin, with a biochemical cocktail that turns back their developmental clock to an embryonic state.
Global warming: the future
Climate change has risen to the top of the political controversy list. But if the majority of experts are right and human activities are driving the world toward a warmer and more unstable climate, then the question of how to reduce its potentially catastrophic impact is one of the most important fields in science.
Opposition has not cut significantly the funding for research. Scientists are working to convert the broad predictions of global warming into more specific, detailed forecasts of how particular regions will be affected. The time period during which weather forecasts morph into climate prediction – between one and 10 years ahead – is especially fertile ground.
Plants to feed the world
With the population set to pass 7 billion this year and rising to 9 billion in mid-century, the world faces a formidable challenge. If everyone is to be fed without appalling environmental consequences, the yield of staple crops must increase enormously. Some plant scientists are still licking their wounds from the onslaught against genetically modified crops. But there is an intensified effort, among public-sector laboratories and industry companies, to breed better plants for farmers. This involves both direct genetic modification to make plants more resistant to stress and disease and the use of genomic information to accelerate improvement through conventional breeding.
The ‘plastic brain’
The 20th-century idea of the adult brain as essentially fixed – incapable of rewiring itself – is changing into a new model of a “plastic” organ that adapts to changing circumstances. If the capacity of one brain region is underused, it can take over some of the functions of an overloaded region.
Recent research has shown that brand-new neurons can grow in at least one key part of the brain, the hippocampus. Neuroscientists are working with plasticity and this “neurogenesis” to find new ways of treating people with mental illness and to learn more about the brain – biology’s greatest challenge.
Population growth and people crowding into mega-cities has made the world more vulnerable to natural and man-made disasters. The fast-growing field of disaster prediction looks for clues that something serious is going wrong, in time for those affected to do something about it.
Although the research covers a very broad field, from the collapse of ecosystems to a crash in financial markets, mathematicians believe that at the fundamental level such events have much in common. Increasingly, powerful computers and mathematical models enable experts to identify signs of impending collapse that would previously have been lost amid all the data.