The most important scientific breakthroughs

THE NOUGHTIES:From the discovery of water on Mars to the discovery of a 10th solar system planet - albeit a dwarf - here, in no particular order, are the most important discoveries of the past 10 years, writes DICK AHLSTROM, Science Editor

The Large Hadron Collider

The largest atom smasher in the world has set records and continues to do so, even as these words are written. The Large Hadron Collider, at Europe’s nuclear research centre at Cern on the French-Swiss border, broke down at start-up in 2008, but restarted last month. It sends twin particle beams racing around a 27km circuit, then smashes them together. On November 30th it set a world record for beam energy, surpassing energy levels achieved in the Tevatron, a particle accelerator based outside Chicago. Cern will continue to push these energy levels to new highs, and next week may allow particle collisions, also then breaking the collision record. The purpose behind the €4 billion machine is to study the fundamental nature of matter and learn more about the Big Bang that created the universe. By January, Cern expects the collider will be operating at energies seven times higher.

The 10th planet

Astronomers made a surprise find in 2005 – a 10th planet orbiting the sun. Eris – aka 136199 Eris – joined the solar-system club, but its inclusion proved a problem. Scientists were already having difficulties, given the discovery of a collection of small planets beyond the orbit of Pluto, plus one in the asteroid belt. The International Astronomical Union stepped in to deliver a formal definition of a planet, and in one step our solar system was down to eight planets, plus five “dwarf planets”. Eris could not be disregarded – it is 27 per cent bigger than Pluto, and ranks as the biggest dwarf. The mini planets comprise Eris, Pluto, Haumea, Makemake and Ceres.

Foxp2 gene

Two mutations in a single gene may have provided the evolutionary push that opened the way to human conversation. It all comes down to a master switch for language, the Foxp2 gene, which was first identified in 2001. It was found because of its associations, when switched off, in speech and language problems in humans. The following year German and British researchers compared our Foxp2 gene with matching ones in chimps, gorillas, orang-utans and rhesus macaque monkeys. They found two alterations seen only in humans, and surmised that these mutations had opened the way to language. Extensive research since has shown how the altered Foxp2 also triggered

physiological changes that delivered the capacity to talk, something that gave humans a huge evolutionary advantage. Researchers are now studying how Foxp2 interacts with a large collection of genes associated with language.

Extrasolar planets

We are not alone in this universe, at least in terms of there being many more planets out there than those found orbiting in our solar system. The past decade has seen the discovery of hundreds of extrasolar or “exoplanets”, as space agencies around the world crank up their efforts to find them. The first tentative discoveries actually occurred in the early 1990s, but in 2000 almost 20 were found, and since then the numbers have climbed, with 75 found so far in 2009. Most of the more than 400 known exoplanets are huge gas giants like Jupiter or Saturn, but astronomers have refined their methods to pinpoint small rocky Earth-like planets. The thinking is that these may harbour life much like our own, and Earth-like planets could also serve as a home away from home if we could develop methods of reaching them.

Reprogrammed pluripotent cells

Japanese scientist Shinya Yamanaka shocked the world in November 2007 when he announced he had successfully “reprogrammed” ordinary adult skin cells to become something akin to an embryonic stem cell. The implications are profound, given the strong scientific belief that in time these cells may be used to cure currently intractable diseases. The previous main source for pluripotent stem cells was by destroying living human embryos, something ethically unpalatable for many. Yamanaka and colleagues discovered a way to turn adult cells back into a pluripotent state, opening up the potential for stem cell research free of the ethical complexities. The method also delivers stem cells perfectly matched to an individual, and without the risk of rejection, given the donor can be the recipient. Much research remains to be done, but if successful then scientists will have a powerful new tool in the battle against disease.

The Toumaï skull

In 2001 fossil hunters discovered a skull in the Djurab Desert in Chad, dated to between six and seven million years old. It was named Sahelanthropus tchadensis, but was quickly nicknamed Toumaï ("hope of life"). The team that discovered Toumaï, led by Michel Brunet of the University of Poitiers, declared it to be a hominid, a human ancestor. Scientists immediately began arguing over its significance, some claiming it to be the missing link between ancient apes and early humans. Others dismissed this view, arguing that it was a gorilla skull. Toumaï now occupies an uncertain place in the human/ape family tree. It has characteristics linked to both but leaves too many questions, with these unlikely to be answered until more fossilised remains can be found.

Cloning

Cloning hasn't gone away you know. Dolly the sheep (1996-2003) is undoubtedly the most famous clone, being the first mammal cloned by inserting an adult cell into an emptied-out egg cell, but the work has continued apace. The last decade has seen a surprising collection of animals join the cloned brigade. A rhesus monkey was cloned in 2000, to be joined in subsequent years by horses, cattle, cats and mules. In 2001 the guar – a large southern Asian bovine – in 2001 became the first endangered species to be cloned, and in 2009 the camel and the Indian water buffalo were cloned. Development of the science could open the way to cloning extinct species, such as the woolly mammoth or make less fanciful Jurassic Park'srecreation of dinosaurs. Its scary side, however, is producing human clones for tissue-matched body parts.

Water on Mars

We almost take for granted the idea that there is water on Mars, but the first solid evidence for it really didn’t begin flowing until 2000, when Nasa made the claim. Since then there has been repeated evidence and new discoveries of water, not just on the surface of Mars but most recently in the constantly shaded craters at the moon’s south pole. It is hugely significant for a number of reasons, given that water can be used in so many ways by humans seeking to visit or live there. As well as needing liquid water for drinking and growing food, it can be split into oxygen for breathing and hydrogen for burning as a fuel. If water is as plentiful as Nasa and Esa satellites and experiments suggest, then the idea of human colonies on Mars and the moon become a real possibility.

MicroRNAs

Small RNAs or microRNAs are pieces of genetic coding that have a massive part to play in health and disease. They were first discovered in 1993, but weren’t named microRNAs until 2001. These tiny bits, between 21 and 23 steps long, control how our genes work, either tuning up genes or damping them down. They help maintain the fine biochemical balance needed to keep our cells working properly, so when they fail to do their job disease can result. For this reason they represent useful targets for pharmaceuticals to counter disease.

The genome zoo

Few collaborative scientific endeavours can match the one that in 2000 delivered the human genome, the complete map of our genetic blueprint. It cost €635 million and took 10 years. Science does not stand still, and since then the genomes of thousands of organisms – from primates to bacteria – have been sequenced in full. They provide an unprecedented method for studying health and disease, and for understanding how cells work. Now scientists hope to create a “genomic zoo” called Genome 10K. A huge international collaboration will deliver the genomes of 10,000 vertebrate species, with a central goal being to develop technology to reduce costs. A genome can now be sequenced for as little as €35,000, but researchers hope to get this down to €700 in the coming years.