Science Top 10

Genome sequencing Ribosome mapping Plastic electronics Human ancestry Adult stem cells Water on Mars Universe's geometry Hormone receptors Near spacecraft Quantum effects

As well as genome sequencing, the journal points to the investigation of the planet Mars as a field in which sensational discoveries have been made in 2000.

The editors highlight important advances in areas such as electrically conducting plastics and the weird world of quantum physics.

There was also the discovery "that went away". This was Archaeoraptor, thought to be a novel combination of bird and dinosaur but exposed as a composite of different fossils.

Year of the genome

But it is genome sequencing that tops the list. Researchers used a synthesis of biology, chemistry, physics, mathematics, computer science, and engineering to read the genetic code of a variety of organisms, from people to fruit flies.

The fly is the biggest animal so far to have its genome completely sequenced

Just a year ago, scientists had completely read the genome of only one multi-cellular organism: the little soil worm Caenorhabditis elegans.

We now have the fruit fly (Drosophila melanogaster) and the soon-to-be-published DNA sequence of humans. A "rough draft" of our sequence was announced in June amid much hullabaloo.

 US President Bill Clinton: "Today we are learning the language in which God created life"

The genomes of several microbes have also been sequenced, such as those that cause cholera and meningitis.

The genomes of the mouse, rat, zebrafish, and two species of puffer fish are also nearing completion.

Commenting on these efforts, the journal's editors say: "Researchers are already reaping new knowledge from these sequencing efforts, including insights into the diversity of cancer, the causes of ageing, and the complexity of the immune system."

Out of Africa

The past year has also witnessed the unveiling of the first molecular map of the ribosome, the cell's protein factory.

This has given us startling new details about its structure and may boost support for an RNA (ribonucleic acid) being the first "living" molecule on Earth.

Evidence in support of the Out of Africa theory mounted in 2000

Fossil skulls unearthed in the Republic of Georgia dated at 1.7 million years old could represent the first human ancestors to journey out of Africa.

According to scientists, the so-called Dmanisi fossils are the first to be discovered outside Africa that show clear signs of African ancestry, and may be linked to the early human species Homo ergaster, the African version of Homo erectus.

Science magazine says research published during 2000 suggests that electrically conducting plastics could form the basis for new technologies using organic molecules.

Some of the original research in this field also won three scientists the 2000 Nobel Prize in chemistry.

The promise is of thousands of organic computer chip components printed on flexible plastic that can be used in flat-panel displays, electronic tags, and perhaps even disposable cell phones.

Cloning advances

The idea that adult cells cannot be converted to another type of cell was shown to be false in 2000.

Studies involving mice and humans proved that adult cells from certain parts of the body can reprogram themselves into other cell types.

If this process can be controlled, healthy adult cells might be useful for repairing tissues damaged by injury or disease.

 The first pig clones are shown off to the world

Cell manipulation has been a constant theme throughout 2000. Researchers also managed to clone a pig, a development which might provide a source of transplantable organs.

A foetal gaur, an endangered animal from India and Southeast Asia, was also produced using cloning technology, raising hopes for rescuing other endangered species.

A red, wet planet

Mars was frequently in the news, especially the possibility that liquid water may still flow on the planet.

Gullies cut into the sides of Martian craters suggest recent running water

High-resolution images of the Martian surface showed signs of recent groundwater seepage and run-off that may be less than a million years old.

 Nasa scientists announce that water may have flowed on Mars recently

Other images of sedimentary rock suggest that the planet may have been a land of lakes during its earliest history.

Data collected by the Galileo spacecraft on Europa, one of Jupiter's major moons, strengthened the case for a salty, global ocean - and possibly life - lurking beneath the satellite's icy shell.

In 2000, astronomers completed the most detailed map of the early Universe with the help of balloons armed with microwave detectors. These were sent aloft to probe for fluctuations in the Cosmic Microwave Background (CMB), the afterglow of the Big Bang.

 "The Universe is flat and will probably expand forever"

The maps made from the data cast doubt on the current simple models of how much ordinary and dark matter exist in the Universe. They suggested the geometry of the Universe was indeed flat.

Weird effects

After orbiting the asteroid Eros for most of the year, the Near-Shoemaker spacecraft has shown that the space rock contains some of the most primitive matter in the Solar System.

This discovery suggests that Eros and other asteroids like it are the suppliers of the most common meteorites arriving on Earth.

And then there was the weird world of the quantum. It just got stranger in 2000. The perplexing idea that objects can be in two places at once has generally been thought to apply only to tiny particles such as electrons.

 The Near spacecraft thrills scientists with its images

But researchers observed this phenomenon on a much larger scale, reporting that an electric current can flow around a superconducting loop of wire in both directions at the same time.

And in January, a scientist challenged another long-standing assumption by showing that quantum computers do not need a quantum property called entanglement to solve complex problems at lightning speed.