Science's breakthrough of the year: Uncovering 'Ardi'

December 17, 2009

The research that brought to light the fossils of Ardipithecus ramidus, a hominid species that lived 4.4 million years ago in what is now Ethiopia, has topped Science's list of this year's most significant scientific breakthroughs. The monumental find predates "Lucy," -- previously the most ancient partial skeleton of a hominid on record -- by more than one million years, and it inches researchers ever-closer to the last common ancestor shared by humans and chimpanzees.

Science and its publisher, AAAS, the nonprofit science society, recognize the Ardipithecus ramidus fossils, including the partial named "Ardi," as 2009's Breakthrough of the Year. They also identify nine other important scientific accomplishments from this past year in a top ten list, appearing in a special news feature in the journal's 18 December 2009 issue.

The Ardipithecus research "changes the way we think about early human evolution, and it represents the culmination of 15 years of painstaking, highly collaborative research by 47 scientists of diverse expertise from nine nations, who carefully analyzed 150,000 specimens of fossilized animals and plants," said Dr. Bruce Alberts, editor-in-chief of Science, in a related editorial.

Back in October, an international team of scientists offered this first comprehensive, peer-reviewed description of Ardipithecus. This research appeared in a special issue of Science, published on 2 October 2009. Until then, the contained only scant evidence of other hominids older than "Lucy."

After analyzing the skull, teeth, pelvis, hands, feet, and other bones, they determined that Ardipithecus possessed a mix of "primitive" traits, shared with its predecessors—the apes of the Miocene epoch—and "derived" traits, which it shared exclusively with later hominids.

However, many of its traits do not appear in modern-day African apes. One surprising conclusion, therefore, is that it is likely that the African apes have evolved extensively since we shared that last common ancestor, which thus makes living chimpanzees and gorillas poor models for the last common ancestor and for understanding our own evolution since that time.

The first Ardipithecus fossils were actually dug up in 1994, but the team of researchers responsible for their discovery was careful not to rush the findings to the public. Instead, more than a decade of detailed analysis and documentation followed, as the experts sent their fossils to various laboratories around the world for evaluation. This collaborative, international effort to study "Ardi" and her environment represents a major scientific landmark of both discovery and analysis.

Science's list of the nine other groundbreaking achievements from 2009 follows:

Pulsars Detected by Fermi: NASA's Fermi Gamma-Ray Space Telescope helped to identify previously unknown pulsars—highly magnetized and rapidly rotating neutron stars—and shed light onto their unique gamma-ray emissions.

Rapamycin: Researchers found that tinkering with a key signaling pathway produces life-extending benefits in mice—the first such result ever achieved in mammals. The discovery was particularly remarkable because the treatment did not start until the mice were middle-aged.

Graphene: In a string of rapid-fire advances, materials scientists probed the properties of —highly conductive sheets of carbon atoms—and started fashioning the material into experimental electronic devices.

Plant ABA Receptors: Solving the structure of a critical molecule that helps plants survive during droughts may help scientists design new ways to protect crops against prolonged dry periods, potentially improving crop yields worldwide and aiding biofuel production on marginal lands.

LCLS at SLAC: SLAC National Accelerator Laboratory unveiled the world's first x-ray laser, a powerful research tool capable of taking snapshots of chemical reactions in progress, altering the electronic structures of materials, and myriad other experiments spanning a wide range of scientific fields.

Gene Therapy Comeback: European and U.S. researchers made progress in treating a fatal brain disease, inherited blindness, and a severe immune disorder by developing new strategies involving gene therapy.

Monopoles: In an experimental coup, physicists working with strange crystalline materials called spin ices created magnetic ripples that model the predicted behavior of "magnetic monopoles," or fundamental particles with only one magnetic pole.

LCROSS Finds Water on the Moon: In October, sensors aboard a NASA spacecraft detected water vapor and ice in the debris from a spent rocket stage that researchers deliberately crashed near the south pole of the Moon.

Hubble Repair: In May, a nearly flawless final repair mission by space-shuttle astronauts gave the Hubble Space Telescope sharper vision and a new lease on life, resulting in its most spectacular images yet.

Areas to Watch: Science's predictions for hot science topics in 2010 include cancer cell metabolism, the Alpha Magnetic Spectrometer, exome sequencing and disease, pluripotent stem cells for neuropsychiatric disease, and the future of human space flight.

The special news feature will also revisit last year's Breakdown of the Year—the financial meltdown—and explore the effects of this year's Virus of the Year—H1N1 flu—on scientific research and collaborations.

Explore further: Ethiopian fossils link ape-men with earlier hominids

More information: On the afternoon of Thursday, December 17, the Breakthrough of the Year articles, plus a related editorial by Bruce Alberts, Science's editor-in-chief, and related multimedia will be available at .

Related Stories

Ethiopian fossils link ape-men with earlier hominids

April 12, 2006

New fossils discovered in the Afar desert of eastern Ethiopia are a missing link between our ape-man ancestors some 3.5 million years ago and more primitive hominids a million years older, according to an international team ...

Early hominid first walked on two legs in the woods

October 8, 2009

Among the many surprises associated with the discovery of the oldest known, nearly complete skeleton of a hominid is the finding that this species took its first steps toward bipedalism not on the open, grassy savanna, as ...

Recommended for you

The hand and foot of Homo naledi

October 6, 2015

The second set of papers related to the remarkable discovery of Homo naledi, a new species of human relative, have been published in scientific journal, Nature Communications, on Tuesday, 6 October 2015.

Who you gonna trust? How power affects our faith in others

October 6, 2015

One of the ongoing themes of the current presidential campaign is that Americans are becoming increasingly distrustful of those who walk the corridors of power – Exhibit A being the Republican presidential primary, in which ...

The dark side of Nobel prizewinning research

October 4, 2015

Think of the Nobel prizes and you think of groundbreaking research bettering mankind, but the awards have also honoured some quite unhumanitarian inventions such as chemical weapons, DDT and lobotomies.

How much for that Nobel prize in the window?

October 3, 2015

No need to make peace in the Middle East, resolve one of science's great mysteries or pen a masterpiece: the easiest way to get yourself a Nobel prize may be to buy one.


Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Dec 17, 2009
"One surprising conclusion, therefore, is that it is likely that the African apes have evolved extensively since we shared that last common ancestor, which thus makes living chimpanzees and gorillas poor models for the last common ancestor"

No Da! Of course! At least your not using the term "missing link".
Dec 17, 2009
This comment has been removed by a moderator.
not rated yet Dec 17, 2009
Of course, if the detection of dark matter (two particles, 25% likelihood from a known source of error instead) is confirmed over the next year to have happened, that would probably top it, in hindsight.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.