The discovery that a class of molecules called "small RNAs" control much of a gene's behavior on Thursday was named 2002's most important scientific breakthrough by the journal Science, one of the world's leading peer-reviewed research magazines.
For decades, RNA (ribonucleic acid) has been viewed primarily as an essential but rather dull molecule that takes order from DNA, which encodes the genetic instructions, and converts that information into proteins, the building blocks of all living things.
But an array of studies this year has revealed that short stretches of RNA, or so-called "small RNAs", can also operate many of the cell's controls by switching various genes on and off, even trimming away unwanted sections of DNA.
These findings are "electrifying", editors at the Science magazine said, and are prompting biologists to overhaul their version of the cell and its evolution and may provide new clues for treating diseases such as cancer.
Besides the research on small RNAs, the Science magazine also identified other nine achievements as runners-up in its annual top ten scientific developments, a list seen by some as "the Oscars in science."
Following are a snapshot of this year's runner-up scientific discoveries, which range from the dawn of time to the dawn of human species.
-- How Neutrinos Escaped Notice. Research this year laid to rest a long-standing mystery about some of the least understood particles in the universe, the neutrinos.
-- Genomes for the Global Good. The sequencing of genetic codes of rice, malaria parasite and the mosquito that carries it in 2002 marked the first year the releasing of genome sequence drafts for organisms with major agriculture and public health relevance for the developing world.
-- Infant Universe in View. In 2002, researchers detected patterns of Cosmic Microwave Background, the leftover energy from the Big Bang which is believed to have created the universe about 14 billion years ago, and found structures far smaller than any seen before, yielding new insights into the motion of matter during the early universe.
-- Spicy Hot and Minty Cool. New discoveries this year helped explain why spicy food feels hot, and breath mints give the mouth a chill. Researchers identified several proteins, embedded in the surfaces of certain cells that respond to both chemical "flavors" and changes in temperature.
-- The Fastest Films. In 2002, researchers caught a glimpse of electrons whizzing around atoms, and made it into a movie. This high-speed film-making technique relies on ultra short pulses of laser light to freeze motion in frames just attoseconds (billionths of a billionth of a second) apart.
-- Look Into the Eyes. This year, several research teams found a new class of light-responsive cells in the retinas of mammals, which may lead to new insights on countering the effects of jet lag or winter depression.
-- Sharpened View of Space. New technology erased the blurring effect of Earth's atmosphere on telescopes' view of the heavens in 2002, resulting in a suite of space images crisper than any taken before.
-- Cells in 3-D. A technology for taking three-dimensional pictures of a cell overcame key technical obstacles in 2002, providing insights into how the cell's machinery carries out some of the basic processes of life.
-- Our Oldest Ancestor Yet. Researchers overturned some fundamental ideas about humans' earliest ancestors in July, 2002, when they reported the startling discovery of a primate skull between 6 and 7 million years old, which is almost 3 million years older than any known hominid.
(People's Daily December 20, 2002)
