Top Science Stories
Top Science
Stories
A carbon threshold breached, commitments to
brain science made, mystery neutrinos found and human evolution revised—these
and other events highlight the year in science and technology as picked by the
blogger of Amazing Facts.
July 25,
2014 |By Deepak Kumar
Recovery of Oldest Human
DNA
For all the astonishing advances in ancient DNA research in recent years, scientists have maintained that they would never be able to sequence DNA from human fossils more than about 100,000 years old. But in December a team reported that it had managed to recover well-preserved DNA from a 400,000-year-old thighbone belonging to an extinct member of the human family.
For all the astonishing advances in ancient DNA research in recent years, scientists have maintained that they would never be able to sequence DNA from human fossils more than about 100,000 years old. But in December a team reported that it had managed to recover well-preserved DNA from a 400,000-year-old thighbone belonging to an extinct member of the human family.
The
thighbone comes from an important site in northern Spain known as the Sima de
los Huesos. Previously researchers had obtained DNA from similarly ancient cave
bear remains found at the site, raising hopes that recovering DNA from the
fossil humans might be next.
The new
sequence furnished some startling insights into the ancestry of the Sima
people. Based on the anatomy of the fossils, experts suspected they belonged to
eitherearly Neandertals or a species
called Homo heidelbergensis that is thought to have given rise
to Neandertals.
But the
DNA they recovered (so-called mitochondrial DNA, which comes from the cell’s
energy-producing structures and constitutes only a small portion of an
individual’s DNA) resembles that of a mysterious human group known as the Denisovans, who lived in Siberia
around 80,000 years ago.
Exactly
how the Sima people came to have a Denisovan-like DNA sequence and not a
Neandertal-like one is unknown. The recovery of DNA from the cell nucleus,
which is far rarer than mitochondrial DNA, would no doubt clarify matters. The
sequencing ofnuclear DNA from a 700,000-year-old horse fossil in
June hints that such a feat may well lie within the realm of possibility. —Kate
Wong
More:
» Earliest Human DNA Shows Unforeseen Mixing with Mystery Population
» Neandertal Genome Study Reveals That We Have a Little Caveman in Us
» Finding My Inner Neandertal
» New DNA Analysis Shows Ancient Humans Interbred with Denisovans
» Earliest Human DNA Shows Unforeseen Mixing with Mystery Population
» Neandertal Genome Study Reveals That We Have a Little Caveman in Us
» Finding My Inner Neandertal
» New DNA Analysis Shows Ancient Humans Interbred with Denisovans
Typhoon Haiyan, the
Strongest Storm Known to Make Landfall
On November 8, 2013, Typhoon Haiyan slammed into the Philippines with sustained winds of 305 to 314 kilometers per hour—making it the strongest storm on record to hit land. Three prior storms, the earliest in 1958, had higher winds when out at sea but had weakened before making landfall. Haiyan is now blamed for more than 6,000 deaths and for destroying or damaging homes of more than six million people.
On November 8, 2013, Typhoon Haiyan slammed into the Philippines with sustained winds of 305 to 314 kilometers per hour—making it the strongest storm on record to hit land. Three prior storms, the earliest in 1958, had higher winds when out at sea but had weakened before making landfall. Haiyan is now blamed for more than 6,000 deaths and for destroying or damaging homes of more than six million people.
High wind
speeds mean great potential damage, because the power in wind increases as the
cube of speed; wind that is twice as fast delivers eight times as much power.
Jeff Masters, director of meteorology at Weather Underground,
estimates that if Haiyan had hit Miami or New York City it could have caused
$500 billion in losses.
The storm
put climate change back on the front
page. Global warming is raising ocean temperatures and putting more moisture
into the atmosphere, and scientists think both of those factors can strengthen
storms. Research since 2007 indicates thathurricanes, typhoons and cyclones—all just
different names for the same type of system—may be getting stronger in the
North Atlantic. And recent research by Kerry Emanuel at the Massachusetts
Institute of Technology indicates that more storms might form, too, in many of
the world’s tropical ocean regions.
Haiyan
also motivated Yeb Sano, head of the Philippines’ delegation to the United
Nations Framework Convention on Climate Change, to take a personal stand
against the lack of progress in international climate talks. At the
convention’s meeting that began in Warsaw, Poland, just three days after the
typhoon wiped out Sano’s hometown, he announced that he would go on a hunger strike until negotiators
made “meaningful progress.” After two weeks he broke his fast, satisfied that
negotiators had agreed on provisions that would address damage from future
climate change events.—Mark Fischetti
More:
» Was Typhoon Haiyan a Record Storm?
» Did Climate Change Cause Typhoon Haiyan?
» How Do Hurricanes Form? An Instant Egghead Video
» Was Typhoon Haiyan a Record Storm?
» Did Climate Change Cause Typhoon Haiyan?
» How Do Hurricanes Form? An Instant Egghead Video
Meteor Explodes over
Chelyabinsk, Russia
The world received a blaring reminder that Earth is at risk from asteroids when a large rock from space exploded over the Russian city of Chelyabinsk on February 15. The meteor flew in at almost 60 times the speed of sound, and its breakup in the atmosphere packed as much energy as 500 kilotons of TNT, later analysis showed. The meteor's shock wave shook the ground, shattered glass and injured about 1,500 people; thankfully, no one was killed. Scientists estimate the asteroid started out about 20 meters wide, making it the largest known meteor to strike Earth since an asteroid hit Tunguska, Siberia, in 1908.
The world received a blaring reminder that Earth is at risk from asteroids when a large rock from space exploded over the Russian city of Chelyabinsk on February 15. The meteor flew in at almost 60 times the speed of sound, and its breakup in the atmosphere packed as much energy as 500 kilotons of TNT, later analysis showed. The meteor's shock wave shook the ground, shattered glass and injured about 1,500 people; thankfully, no one was killed. Scientists estimate the asteroid started out about 20 meters wide, making it the largest known meteor to strike Earth since an asteroid hit Tunguska, Siberia, in 1908.
The Chelyabinsk fireball came as a surprise,
even to those at NASA and the rest of the world's space agencies, which had not
spotted the asteroid in advance. And it struck just 16 hours before another,
larger asteroid, 2012 DA14, made a close flyby of Earth, passing within the
orbital range of geosynchronous communications satellites.
The
events were a wake-up call to some about the dangers asteroids pose. In October
the United Nations took steps to address the risk by setting up an “International Asteroid Warning Group” for
member nations to share detections of hazardous space rocks. If scientists
discover an asteroid with Earth's name on it, the U.N.’s Committee on the
Peaceful Uses of Outer Space plans to spearhead an international mission to
deflect the rock from its course. —Clara Moskowitz
More:
» Chelyabinsk Eyewitnesses Help Scientists Resolve Meteor Mysteries
» What Do We Know about the Russian Meteor?
» United Nations to Adopt Asteroid Defense Plan
» Chelyabinsk Eyewitnesses Help Scientists Resolve Meteor Mysteries
» What Do We Know about the Russian Meteor?
» United Nations to Adopt Asteroid Defense Plan
Atmospheric CO2 Reaches a
Historical High: 400 Parts per Million
In May concentrations of carbon dioxide in the atmosphere reached 400 parts per million. In other words, human activity, such as fossil-fuel burning and cutting down forests, has boosted greenhouse gas levels to concentrations not seen in at least 800,000 years—or well before human civilization and even modern humans existed.
In May concentrations of carbon dioxide in the atmosphere reached 400 parts per million. In other words, human activity, such as fossil-fuel burning and cutting down forests, has boosted greenhouse gas levels to concentrations not seen in at least 800,000 years—or well before human civilization and even modern humans existed.
In fact,
the last time CO2 levels are known to have been this high was in the Pliocene epoch more than 2.5
million years ago, when the Arctic boasted forests instead of tundra and the
world's average temperature was roughly 3 degrees Celsius warmer. The CO2 in
the atmosphere has already boosted average temperatures by 0.8 degree C since
the 19th century, and more warming is in store.
More CO2
is in the offing as well. At the present pace, the world could reach 450 ppm in
a few decades, ratcheting up concentrations by two ppm or more per year. Ideas
for what to do about it range from building artificial trees to pull CO2 out of
the air to replacing all fossil fuel–fired power plants with nuclear reactors.
But it seems safe to say CO2 levels will get higher—and the globe warmer—before
long. —David Biello
More:
» Dangerous Global Warming Closer Than You Think, Climate Scientists Say
» 400 PPM: Carbon Dioxide in the Atmosphere Reaches Prehistoric Levels
» 400 PPM: What’s Next for a Warming Planet? An In-Depth Report
» Dangerous Global Warming Closer Than You Think, Climate Scientists Say
» 400 PPM: Carbon Dioxide in the Atmosphere Reaches Prehistoric Levels
» 400 PPM: What’s Next for a Warming Planet? An In-Depth Report
U.S. Sequestration: A Body
Blow to Science
U.S. researchers shuddered on March 1, 2013, when the sweeping federal budget cuts known as the sequester went into effect. Born amid congressional failure to strike a budget deal, sequestration forced the slashing $85 billion in government spending for the remainder of the fiscal year—and with it, a cascade of cuts to research funding.
U.S. researchers shuddered on March 1, 2013, when the sweeping federal budget cuts known as the sequester went into effect. Born amid congressional failure to strike a budget deal, sequestration forced the slashing $85 billion in government spending for the remainder of the fiscal year—and with it, a cascade of cuts to research funding.
That $85
billion was just the start: blunt, across-the-board cuts of $1.2 trillion
kicked in, spooling out over nine years through 2021. The mandatory pruning
injected uncertainty into the future of science research because the federal
government holds the purse strings for more than one third of all research and
development in the U.S. Not only did sequestration force the government to
slash funding for grants, it also delayed or scuttled plans to bring on new
hires. Research groups lamented that the litany of cuts will have long-lasting
impacts on innovation because scientific advancement is an incremental process
that depends on future researchers—and research—in the pipeline. Francis Collins,
director of the National Institutes of Health, even grabbed his guitar and
literally sang the “Sequester Blues” this past spring.
Research
across a broad spectrum felt the heat. The NIH, the country’s largest supporter
of basic reach, had to crop its budget by $1.6 billion for the fiscal year.
Those funding constraints helped contribute to 640 fewer research project
grants compared with the prior year. The National Science Foundation, hit with
$283 million in cuts, also doled out about 700 fewer grants this year. Research
grants fluctuate naturally each year, but reductions in various agencies were
far greater than the norm. Federally supported science at other
agencies—including the U.S. Environmental Protection Agency, Department of
Energy and NASA—will also likely feel the budget bite, if they haven’t already.
A new
congressional deal, unveiled December 10, may staunch some of the
funding loss. But the full impact of the cuts so far is shrouded in uncertainty
and may have already set back U.S. innovation for years. —Dina Fine Maron
More:
» Sequestered Science: How Research Got Tied Up with Federal Dollars [Timeline]
» Sequestration Shovels Money to the Russians
» Sequester Cuts to Science Slow Biomedical Research
» There Should Be Grandeur: Science in the Shadow of the Sequester
» Sequestered Science: How Research Got Tied Up with Federal Dollars [Timeline]
» Sequestration Shovels Money to the Russians
» Sequester Cuts to Science Slow Biomedical Research
» There Should Be Grandeur: Science in the Shadow of the Sequester
Honorable Mentions
In no particular order:
In no particular order:
·
The U.S. Supreme
Court strikes down patents on the cancer genes BRCA1 andBRCA2,
ruling that naturally occurring genes cannot be patented.
·
Carbon-nanotube
computers could replace
today’s machines built on silicon, thanks to a new, scalable manufacturing
process.
·
Memory of a fearful
experience can be passed down at least two generations because of epigenetics, the study
of how our experiences toggle genes on or off.
·
The U.S. Food and Drug
Administration tells personal genomics testing company 23andMe in
November to stop marketing its kits, which can also be seen as
a massive
information-gathering operation.
·
The Chang’e 3 rover makes
China the third nation to visit the moon. The achievement shows how space
technology is spreading to other nations and to private companies, which
continue to show their ability in launches.
·
Spectacular human
fossil skeletons in South Africa
rewrite our family history and introduce new relatives.
·
A plethora of Earth-like
exoplanets has been found in
the Milky Way Galaxy by Kepler, NASA’s planet-hunting satellite.