Top ten developments of 2005

THIS YEAR, scientists piled up new insights about evolution at the genetic level and the birth of species, including information that could help us lead healthier lives in the future.
Ironically, these often-startling discoveries occurred in a year when backers of `intelligent design' and other opponents of evolution sought to renew challenges to this fundamental concept.
This milestone, plus nine other research advances, make up Science's list of the top ten scientific developments in 2005, chosen for their profound implications for society and the advancement of science.
Many of this year's breakthrough studies followed evolution at the genetic level. In October this year, an international team of researchers unveiled a map of the chimpanzee genome.
The biggest map to date of single-letter variations in the human genetic sequence, hoping to get a better glimpse of the human species' evolutionary history is another development.
This year's sequencing of the 1918 pandemic flu virus could have a more immediate impact on medicine. Other studies showed how small changes in DNA can trigger dramatic evolutionary events. Researchers found that a single genetic change can be all it takes to turn one species into many.
Beyond the genome, researchers watched evolution in action among a number of animals, from caterpillars to crickets, and found that behavioural differences such as what to eat and when to mate may be enough to turn a single population into two species. Science also salutes nine other scientific achievements of 2005.
Planetary safaris: With spacecraft at or on the way to the moon, Mercury, Venus, Mars, a comet, an asteroid, Saturn, and the very edge of the solar system, planetary discovery soared in 2005.
The high point in a year of highlights may be the landing of the European spacecraft Huygens on Titan, Saturn's largest moon. Huygens' trip to Titan revealed a world where infrequent but drenching rains of liquid methane shape the land and participate in a fascinating hydrologic cycle.
A rich year for plants: Several key molecular cues behind flowering and other plant mysteries and surprises came to light in 2005. For example, plant molecular biologists pinned down the identity of a signal that initiates the seasonal development of flowers. Other research focused on a gene involved in stimulating flowering, and another study highlighted a surprising cache of RNA.
The nature of neutron stars: In 2005, new instruments yielded vivid insights into the most violent behaviours of neutron stars. A short, intense pulse of radiation from near the centre of the Milky Way, recorded on 27 December 2004, may be the result of a short gamma ray burst — a rapid merger of two ancient neutron stars or a neutron star and a black hole.
Brain wiring and disease: Several studies in 2005 suggest that diseases like schizophrenia, Tourette syndrome, and dyslexia are rooted in `faulty wiring' of the brain's neural circuitry during development in the womb.
Where did Earth come from? This year, researchers took another look at Earth rocks and meteorites that resemble the starting material of the solar system and found that their atoms were significantly different. So where did Earth get its building blocks?
Some scientists now say early Earth materials come from a different part of the solar system, while others say parts of early Earth are just sunk deep in the planet, hidden from view.
Key protein's close-up: The most detailed molecular portrait to date of a voltage-gated potassium channel was unveiled in 2005. These channels, gatekeeper proteins that usher potassium ions in and out of cells, are as key to nerve and muscle functioning as transistors are to computers.
Changing climate of climate change? In 2005, evidence linking humans to global warming continued to accumulate and U.S. politicians began to take notice.
From the warming of deep ocean waters and increased frequencies of the most intense tropical cyclones to continued reductions in ice cover in the Arctic Ocean and altered bird migratory patterns, scientific evidence for climate change built up in 2005 and non-scientists seem to have listened.
Cell signalling steps up: Dynamic views of how cells respond to the chemical and environmental signals all around them took hold in 2005 thanks to efforts to track multiple inputs and outputs of cell signalling networks simultaneously.
For example, researchers created a model of nearly 8,000 chemical signals involved in a network leading to programmed cell death.
ITER lands in France: The struggle over the location of the world's first fusion reactor has ended — the International Thermonuclear Experimental Reactor (ITER) will be built at Cadarache in southern France and not in Rokkasho, Japan. One aim of ITER is to generate fusion-powered electricity by recreating the power of the sun on Earth.
Areas to watch in 2006: According to Science's predictions for hot fields include drug and vaccine development for avian flu, RNA-interference in humans, high-temperature superconductors, the microbial family tree, detection of the merging of two neutron stars and ultrahigh-energy cosmic rays.