Science's special issue includes its opinion of the breakthroughs of the year:
1.proof of the Poincaré conjecture;
To mathematicians, Grigori Perelman's proof of the Poincaré conjecture qualifies at least as the Breakthrough of the Decade. But it has taken them a good part of that decade to convince themselves that it was for real. In 2006, nearly 4 years after the Russian mathematician released the first of three papers outlining the proof, researchers finally reached a consensus that Perelman had solved one of the subject's most venerable problems. But the solution touched off a storm of controversy and drama that threatened to overshadow the brilliant work.
2.digging out fossil DNA from Neandertal;
This year, on the 150th anniversary of the discovery of the Neandertal type specimen, researchers in Europe and the United States transformed the study of this ancient human by sequencing more than 1 million bases of Neandertal DNA. In November, two groups, one decoding 65,000 Neandertal bases and the other a million bases, showed that researchers can now find sequence changes between modern and ancient humans, differences that may reveal key steps in our evolution. The studies concluded that Neandertals diverged from our own ancestors at least 450,000 years ago--approximately the time suggested by fossil and mitochondrial DNA studies. One group's data also suggest that Neandertals and modern humans may have interbred. In the works are a very rough draft of the complete Neandertal genome sequence and, as more fossils become available to sequencers, the development of bacterial libraries containing DNA from several Neandertals.
3.shrinking ice sheets in Greenland and Antartica;
Glaciologists nailed down an unsettling observation this year: The world's two great ice sheets--covering Greenland and Antarctica--are indeed losing ice to the oceans, and losing it at an accelerating pace. Researchers don't understand why the massive ice sheets are proving so sensitive to an as-yet-modest warming of air and ocean water. The future of the ice sheets is still rife with uncertainty, but if the unexpectedly rapid shrinkage continues, low-lying coasts around the world--including New Orleans, South Florida, and much of Bangladesh--could face inundation within a couple of centuries rather than millennia.
4.375 million year old fish that breathed;
Paleontologists made a major splash this year with the debut of a fossil fish that long ago took a deep breath and made some tentative but ultimately far-reaching steps onto land. With its sturdy, jointed fins, the 375-million-year-old specimen fills an evolutionary gap and provides a glimpse of the features that helped later creatures conquer the continents.
5.the ultimate camoflage;
Science veered toward science fiction this year as physicists cobbled together the first rudimentary invisibility cloak. Although far from perfect--the ring-shaped cloak is invisible only when viewed in microwaves of a certain wavelength traveling parallel to the plane of the ring--the device could usher in a potentially revolutionary approach to manipulating electromagnetic waves.
6.hope against age-related macular degeneration;
The year brought good news to the many people suffering from the vision-robbing disease known as age-related macular degeneration (AMD).In October, The New England Journal of Medicine published the results of two clinical trials showing that treatment with the drug ranibizumab improves the vision of roughly one-third of patients with the more serious wet form of AMD and stabilizes the condition of most of the others. Other approved treatments can only slow the progression of AMD.
7.biodiversity;
It doesn't take much to send an organism down speciation's path. Several studies these past 12 months have uncovered genetic changes that nudge a group of individuals toward becoming a separate species by giving them an edge in a new environment. The year's results speak to the power of genomics in helping evolutionary biologists understand one of biology's most fundamental questions: how biodiversity comes about.
8.looking past the light barrier;
Biologists got a clearer view of the fine structure of cells and proteins this year, as microscopy techniques that sidestep a fundamental limit of optics moved beyond proof-of-principle demonstrations to biological applications. The advances could open a new realm of microscopy.
An ordinary microscope cannot resolve features smaller than half the wavelength of the light used to illuminate an object--about 200 nanometers for visible light. For years, physicists and engineers have devised schemes to get around the "diffraction limit," and this year, researchers used those techniques to do some real biology.
9.persistence of memory;
How the brain records new memories is a central question in neuroscience. One attractive possibility involves a process called longterm potentiation (LTP) that strengthens connections between neurons. Many neuroscientists suspect that LTP is a memory mechanism, but proving it hasn't been easy. Several findings reported this year strongly bolstered the case.
10.RNA molecules shutting down gene expression;
Small RNA molecules that shut down gene expression have been hot, hot, hot in recent years, and 2006 was no exception. Researchers reported the discovery of what appears to be a new and still-mysterious addition to this exclusive club: Piwi-interacting RNAs (piRNAs). Abundant in the testes of several animals, including humans, piRNAs are distinctly different from their small RNA cousins, and scientists are racing to learn more about them and see where else in the body they might congregate.
1.proof of the Poincaré conjecture;
To mathematicians, Grigori Perelman's proof of the Poincaré conjecture qualifies at least as the Breakthrough of the Decade. But it has taken them a good part of that decade to convince themselves that it was for real. In 2006, nearly 4 years after the Russian mathematician released the first of three papers outlining the proof, researchers finally reached a consensus that Perelman had solved one of the subject's most venerable problems. But the solution touched off a storm of controversy and drama that threatened to overshadow the brilliant work.
2.digging out fossil DNA from Neandertal;
This year, on the 150th anniversary of the discovery of the Neandertal type specimen, researchers in Europe and the United States transformed the study of this ancient human by sequencing more than 1 million bases of Neandertal DNA. In November, two groups, one decoding 65,000 Neandertal bases and the other a million bases, showed that researchers can now find sequence changes between modern and ancient humans, differences that may reveal key steps in our evolution. The studies concluded that Neandertals diverged from our own ancestors at least 450,000 years ago--approximately the time suggested by fossil and mitochondrial DNA studies. One group's data also suggest that Neandertals and modern humans may have interbred. In the works are a very rough draft of the complete Neandertal genome sequence and, as more fossils become available to sequencers, the development of bacterial libraries containing DNA from several Neandertals.
3.shrinking ice sheets in Greenland and Antartica;
Glaciologists nailed down an unsettling observation this year: The world's two great ice sheets--covering Greenland and Antarctica--are indeed losing ice to the oceans, and losing it at an accelerating pace. Researchers don't understand why the massive ice sheets are proving so sensitive to an as-yet-modest warming of air and ocean water. The future of the ice sheets is still rife with uncertainty, but if the unexpectedly rapid shrinkage continues, low-lying coasts around the world--including New Orleans, South Florida, and much of Bangladesh--could face inundation within a couple of centuries rather than millennia.
4.375 million year old fish that breathed;
Paleontologists made a major splash this year with the debut of a fossil fish that long ago took a deep breath and made some tentative but ultimately far-reaching steps onto land. With its sturdy, jointed fins, the 375-million-year-old specimen fills an evolutionary gap and provides a glimpse of the features that helped later creatures conquer the continents.
5.the ultimate camoflage;
Science veered toward science fiction this year as physicists cobbled together the first rudimentary invisibility cloak. Although far from perfect--the ring-shaped cloak is invisible only when viewed in microwaves of a certain wavelength traveling parallel to the plane of the ring--the device could usher in a potentially revolutionary approach to manipulating electromagnetic waves.
6.hope against age-related macular degeneration;
The year brought good news to the many people suffering from the vision-robbing disease known as age-related macular degeneration (AMD).In October, The New England Journal of Medicine published the results of two clinical trials showing that treatment with the drug ranibizumab improves the vision of roughly one-third of patients with the more serious wet form of AMD and stabilizes the condition of most of the others. Other approved treatments can only slow the progression of AMD.
7.biodiversity;
It doesn't take much to send an organism down speciation's path. Several studies these past 12 months have uncovered genetic changes that nudge a group of individuals toward becoming a separate species by giving them an edge in a new environment. The year's results speak to the power of genomics in helping evolutionary biologists understand one of biology's most fundamental questions: how biodiversity comes about.
8.looking past the light barrier;
Biologists got a clearer view of the fine structure of cells and proteins this year, as microscopy techniques that sidestep a fundamental limit of optics moved beyond proof-of-principle demonstrations to biological applications. The advances could open a new realm of microscopy.
An ordinary microscope cannot resolve features smaller than half the wavelength of the light used to illuminate an object--about 200 nanometers for visible light. For years, physicists and engineers have devised schemes to get around the "diffraction limit," and this year, researchers used those techniques to do some real biology.
9.persistence of memory;
How the brain records new memories is a central question in neuroscience. One attractive possibility involves a process called longterm potentiation (LTP) that strengthens connections between neurons. Many neuroscientists suspect that LTP is a memory mechanism, but proving it hasn't been easy. Several findings reported this year strongly bolstered the case.
10.RNA molecules shutting down gene expression;
Small RNA molecules that shut down gene expression have been hot, hot, hot in recent years, and 2006 was no exception. Researchers reported the discovery of what appears to be a new and still-mysterious addition to this exclusive club: Piwi-interacting RNAs (piRNAs). Abundant in the testes of several animals, including humans, piRNAs are distinctly different from their small RNA cousins, and scientists are racing to learn more about them and see where else in the body they might congregate.
