Suminia: Life in the Trees 260 Million Years Ago
(Laelaps, May 28, 2010)
When I hear the phrase “early human relative” I cannot help but think of an ape-like creature. Something like Sahelanthropus fits the bill nicely – it may not be a hominin but it is still a close relative from around the time that the first hominins evolved. That is why I was a bit puzzled to see MSNBC.com parroting a story written by the Discovery Channel which proclaimed “Early human relative predates even dinosaurs”! Was this another fossil that would change everything? While not quite as startling as a Precambrian rabbit, a 260-million-year-old-hominin (or even primate) would certainly be a shocker!
The truth of the matter, however, is that the fossil described in the MSNBC story is only a distant relative of humans. Called Suminia getmanovi, it was a synapsid (the diverse group of vertebrates to which mammals and their closest relatives belong) that lived during the Permian in what is now Russia. More specifically, it was an anomodont, or a relative of the tubby Lystrosaurus and the small, tusked Robertia. The attempt to make Suminia relevant to human ancestry, therefore, was a quick and dirty way of grabbing attention, but in this case I think it stirred more confusion than enlightenment.
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Ocean heat content increases update
(RealClimate, May 29, 2010)
There is a new paper in Nature this week on recent trends in ocean heat content from a large group of oceanographers led by John Lyman at PMEL. Their target is the uncertainty surrounding the various efforts to create a homogenised ocean heat content data set that deals appropriately with the various instrument changes and coverage biases that have plagued previous attempts.
We have discussed this issue a number of times because of its importance in diagnosing the long term radiative imbalance of the atmosphere. Basically, if there has been more energy coming in at the top than is leaving, then it has to have been going somewhere – and that somewhere is mainly the ocean. (Other reservoirs for this energy, like the land surface or melting ice, are much smaller, and can be neglected for the most part).
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On attribution
(RealClimate, May 29,2010)
How do we know what caused climate to change – or even if anything did?
This is a central question with respect to recent temperature trends, but of course it is much more general and applies to a whole range of climate changes over all time scales. Judging from comments we receive here and discussions elsewhere on the web, there is a fair amount of confusion about how this process works and what can (and cannot) be said with confidence. For instance, many people appear to (incorrectly) think that attribution is just based on a naive correlation of the global mean temperature, or that it is impossible to do unless a change is ‘unprecedented’ or that the answers are based on our lack of imagination about other causes.
In fact the process is more sophisticated than these misconceptions imply and I’ll go over the main issues below. But the executive summary is this:
STRONG EVIDENCE ON CLIMATE CHANGE UNDERSCORES NEED FOR ACTIONS TO REDUCE EMISSIONS AND BEGIN ADAPTING TO IMPACTS
at 11:12 am on Tuesday, 25 May 2010
(News from the National Academies, May 19, 2010)
WASHINGTON — As part of its most comprehensive study of climate change to date, the National Research Council today issued three reports emphasizing why the U.S. should act now to reduce greenhouse gas emissions and develop a national strategy to adapt to the inevitable impacts of climate change. The reports by the Research Council, the operating arm of the National Academy of Sciences and National Academy of Engineering, are part of a congressionally requested suite of five studies known as America’s Climate Choices.
“These reports show that the state of climate change science is strong,” said Ralph J. Cicerone, president of the National Academy of Sciences. “But the nation also needs the scientific community to expand upon its understanding of why climate change is happening, and focus also on when and where the most severe impacts will occur and what we can do to respond.”
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Tracking the Ancestry of Corn Back 9,000 Years
at 8:50 am on Tuesday, 25 May 2010
It is now growing season across the Corn Belt of the United States. Seeds that have just been sown will, with the right mixture of sunshine and rain, be knee-high plants by the Fourth of July and tall stalks with ears ripe for picking by late August.
Corn is much more than great summer picnic food, however. Civilization owes much to this plant, and to the early people who first cultivated it.
(New York Times, May 25, 2010)
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Mediterranean Sea Getting Saltier, Hotter
at 2:52 pm on Monday, 24 May 2010
The Western Mediterranean Sea is heating up and getting saltier, a new study finds.
Each year the temperature of the deep layer of the Western Mediterranean increases by 0.0036 degrees Fahrenheit (0.002 degrees Celsius), and its salt levels increase by 0.001 units of salinity, researchers monitoring the sea found. The change is consistent with the expected effects of global warming.
These changes may sound like small beans, but they have been building up at a faster pace since the 1990s, the study, detailed in the April 1 edition of the Journal of Geophysical Research, suggests.
(Live Science, May 24, 2010)
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I, microbe: Sequencing the bugs in our bodies
20 May 2010 by Caitlin Stier
People are more microbe than human, with microbes outnumbering our cellsby 10 to 1. But strangely, scientists know more about the microbes that inhabit the soil and sea than those that call us home. Now, the genetic sequencing of 178 of these microbes will help close that gap.
Scientists have long known that our microbial inhabitants, collectively known as the microbiome, can contribute to disease. But culturing the cells outside of the human body can be difficult, complicating efforts to identify many of them, particularly rare species.
Read the rest of this entry here.
U.S. Science Body Urges Action on Climate
at 11:27 am on Thursday, 20 May 2010
By JOHN M. BRODER
(NY Times, May 19, 2010)
WASHINGTON — In its most comprehensive study so far, the nation’s leading scientific body declared on Wednesday that climate change is a reality and is driven mostly by human activity, chiefly the burning of fossil fuels and deforestation.
The group, the National Research Council, an arm of the National Academy of Sciences, issued three reports describing the case for a harmful human influence on the global climate as overwhelming and arguing for strong immediate action to limit emissions of climate-altering gases in the United States and around the world — including the creation of a carbon pricing system.
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The Anthropocene Debate: Marking Humanity’s Impact
(Yale:Environment 360, May 17, 2010)
Marking Humanity’s Impact
Is human activity altering the planet on a scale comparable to major geological events of the past? Scientists are now considering whether to officially designate a new geological epoch to reflect the changes thathomo sapiens have wrought: the Anthropocene.
by elizabeth kolbert
The Holocene — or “wholly recent” epoch — is what geologists call the 11,000 years or so since the end of the last ice age. As epochs go, the Holocene is barely out of diapers; its immediate predecessor, the Pleistocene, lasted more than two million years, while many earlier epochs, like the Eocene, went on for more than 20 million years. Still, the Holocene may be done for. People have become such a driving force on the planet that many geologists argue a new epoch — informally dubbed the Anthropocene — has begun.
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New Study Finds Ocean Warmed Significantly Since 1993
at 7:53 am on Thursday, 20 May 2010
(NASA, May 20, 2010)
The upper layer of Earth’s ocean has warmed since 1993, indicating a strong climate change signal, according to a new international study co-authored by oceanographer Josh Willis of NASA’s Jet Propulsion Laboratory, Pasadena, Calif. The energy stored is enough to power nearly 500 100-watt light bulbs for each of the roughly 6.7 billion people on the planet.
“We are seeing the global ocean store more heat than it gives off,” said John Lyman, an oceanographer at the National Oceanic and Atmospheric Administration’s Joint Institute for Marine and Atmospheric Research, who led the study that analyzed nine different estimates of heat content in the upper ocean from 1993 to 2008.
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What we can learn from studying the last millennium (or so)
(Real Climate, May 15, 2010)
With all of the emphasis that is often placed on hemispheric or global mean temperature trends during the past millennium, and the context they provide for interpreting modern warming trends, one thing is often lost in the discussion: space matters as much as time. Indeed, it is likely that the regional patterns of past climate changes, rather than simple hemispheric or global mean temperature trends, will best inform our understanding of the dynamical mechanisms involved. Since much of the uncertainty in future projections relates to regional climate change impacts, it makes particular sense to focus on those changes in the past that involve regional changes and the underlying mechanisms behind them.
For instance, melting of the cryosphere (and consequent rises in sea level), subtle shifts in drought and rainfall patterns, and extreme events, are all regional effects that could be important threats to ecosystems and our environment. Such changes are often associated with phenomena like ENSO or the North Atlantic Oscillation. Yet there remain large uncertainties about how such mechanisms will respond to anthropogenic climate change.
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Smallest waterlily in the world saved from extinction – by Kew Gardens
(guardian.co.uk, May 19, 2010)
The thermal waterlily, extinct in the wild since it disappeared from Rwanda in 2008, has been granted a new lease of life.
Plant experts at Kew Gardens have rescued the smallest waterlily in the world from the brink of extinction.
The thermal waterlily has not grown in the wild since the last specimens vanished two years ago from its only known habitat, a hot spring in southwest Rwanda.
After a year-long struggle, a Kew Gardens biologist worked out a way to grow the plants at the botanic gardens, paving the way for their reintroduction in the wild.
Read the rest of this entry here.
New Climate Physics forum link added to arguendo
Has the greenhouse effect been falsified?
at 7:20 am on Wednesday, 19 May 2010
(Skeptical Science, May 19, 2010)
Most participants in climate debates can agree that the atmosphere’s capacity to interact with thermal radiation helps maintain the Earth’s surface temperature at a livable level. The Earth’s surface is about 33 degrees Celsius warmer than required to radiate back all the absorbed energy from the Sun. This is possible only because most of this radiation is absorbed in the atmosphere, and what actually escapes out into space is mostly emitted from colder atmosphere.
Read the rest of this entry here.
Ancient mass extinction of fish may have paved way for modern species
By Amina Khan, Los Angeles Times
May 17, 2010 | 3:56 p.m.
A report looks at a 360-million-year-old gap in the fossil record and finds that marine vertebrates were recovering from an extinction event on par with the one that killed the dinosaurs. What happened is unclear.
Modern-day lizards, snakes, frogs and mammals — including us — may owe their existence to a mass extinction of ancient fish 360 million years ago that left the oceans relatively barren, providing room for marginal species that were our ancestors to thrive and diversify, paleontologists said Monday.
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NOAA: Warmest April Global Temperature on Record
at 10:44 am on Tuesday, 18 May 2010
The combined global land and ocean surface temperature was the warmest on record for both April and for the period from January-April, according to NOAA. Additionally, last month’s average ocean surface temperature was the warmest on record for any April, and the global land surface temperature was the third warmest on record.
The monthly analysis from NOAA’s National Climatic Data Center, which is based on records going back to 1880, is part of the suite of climate services that NOAA provides government, business and community leaders so they can make informed decisions.
(NOAA, My 17, 2010)
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Creatures of Cambrian May Have Lived On
at 6:21 am on Tuesday, 18 May 2010
Ever since their discovery in 1909, the spectacular Burgess Shale outcrops in the Canadian Rockies have presented scientists with a cornucopia of evidence for the “explosion” of complex, multicellular life beginning some 550 million years ago.
The fossils, all new to science, were at first seen as little more than amazing curiosities from a time when life, except for bacteria and algae, was confined to the sea — and what is now Canada was just south of the Equator. In the last half century, however, paleontologists recognized that the Burgess Shale exemplified the radiation of diverse life forms unlike anything in earlier time. Here was evolution in action, organisms over time responding to changing fortunes through natural experimentation in new body forms and different ecological niches.
(New York Times, May 17, 2010)
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The majestic Megatherium
at 6:04 am on Tuesday, 18 May 2010
For over a century and a half dinosaurs have been the unofficial symbols and ambassadors of paleontology, but this was not always so. It was fossil mammals, not dinosaurs, which enthralled the public during the turn of the 19th century, and arguably the most famous was the enormous ground slothMegatherium. It was more than just a natural curiosity. The bones of the “great beast” represented a world which flourished and disappeared in the not-so-distant past, but, as illustrated by Christine Argot in a review of its history, illustrations of whatMegatherium looked like have been in flux since the time of its discovery.
No doubt humans have been finding the remains of giant ground sloths for quite some time, but the story of Megatherium as we know it began in 1788. It was in that year that Manuel Torres discovered the nearly complete skeleton of an immense, strange animal on the banks of the river Luján about 65 kilometers west of Buenos Aires in northern Argentina. . .
(Laelaps, May 18, 2010)
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The significance of the CO2 lag
at 5:56 am on Tuesday, 18 May 2010
When we examine past climate change using ice cores, we observe that CO2 lags temperature. In other words, a change in temperature causes changes in atmospheric CO2. This is due to various processes such as warmer temperatures causing the oceans to release CO2. This has lead some to argue that the CO2 lag disproves the warming effect of CO2. However, this line of thinking doesn’t take in the full body of evidence. We havemany lines of empirical evidence that CO2 traps heat. Decades of lab experiments reveal how CO2 absorbs and scatters infrared radiation. Satellite measurements find CO2 trapping heat and surface measurements confirm more radiation at CO2 wavelengths returning to the Earth’s surface. So the full body of evidence gives us these two facts: warming causes more CO2 and more CO2 causes warming. The significance should by now be obvious. The CO2 lag is evidence of a climate positive feedback.
(Skeptical Science, May 18, 2010)
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Giant oarfish caught off Sweden
at 9:29 am on Monday, 17 May 2010
. . . The giant oarfish, also known as “the king of herrings” (Regalecus glesne), is the world’s largest bony fish (“teleost”), and can grow up to 11 meters (36 feet) long! It’s rarely photographed because it lives in the deep sea, but one just washed up on the coast of Sweden, where it hasn’t been seen for 150 years. They eat plankton. Until today I didn’t know these creatures existed.
(Why Evolution is True, May 17, 2010)
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Is Africa’s Lake Tanganyika -One of the Planet’s Most Ancient & Deepest Lakes is Endangered?
at 8:32 am on Monday, 17 May 2010
Geologists led by Brown University have determined that Lake Tanganyika, the source of the Congo River, has experienced unprecedented warming during the last century, and its surface waters are the warmest on record. Lake Tanganyika is bordered by Burundi, the Democratic Republic of Congo, Tanzania, and Zambia — four of the poorest countries in the world, according to the United Nations Human Development Index. An estimated 10 million people live near the lake, and they depend upon it for drinking water and for food. Fishing is a crucial component for the region’s diet and livelihood: Up to 200,000 tons of sardines and four other fish species are harvested annually from Lake Tanganyika, a haul that makes up a significant portion of local residents’ diets, according to a 2001 report by the Lake Tanganyika Biodiversity Project.
(The Daily Galaxy, May 17, 2010)
Woody Guthrie award to The Science of Doom
at 8:18 am on Monday, 17 May 2010
Back in February, Skeptical Science was honoured to receive the Woody Guthrie award from Dan’s Wild Science Journal. The idea is the award gets passed on from blog to blog, to those whom they deem a ‘thinking blog’. I’ve been sitting on it for nearly 3 months now but it’s time to dust off the award and regretfully pass it onto a worthier recipient. I’ve been agonising between a well known climate blog which I’ve admired for years and a newer, lesser known blog which has been a favourite haunt of mine in recent months. Finally, I made a decision today and have passed the award onto The Science of Doom by Steve Carson.
(Skeptical Science, May 10, 2010)
Read the rest of the entry here.
How important is group selection?
at 8:04 am on Monday, 17 May 2010
The idea that selection operates on entire groups rather than individuals, and can lead to the evolution of group-level traits (altruism is supposed to be one of these), has been revived by several people. Among them are E. O. Wilson, but especially David Sloan Wilson, who has defended his notion of group selection in a fifteen-part (!) series on HuffPo, infelicitiously called “Truth and Reconciliation for Group Selection.”. . .
Fortunately, you can get an excellent summary of the state of the field in a little over an hour, thanks to the London Evolutionary Research Network, a consortium of researchers who hold regular meetings and debates. Last July, they held a very nice debate, “Is natural selection at the group level an important evolutionary force?” which is now available at Vimeo.
(Why Evolution Is True, May 17, 2010)
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Climate Bill Cheat Sheet
After six months of grueling negotiations, John Kerry (D-Mass.) and Joe Lieberman (I-Conn.) on Wednesday unveiled a 987-page draft of climate and energy legislation that they believe can win the support of 60 senators. “We are closer than we’ve ever been to a breakthrough,” said Kerry at the bill’s release. Notably absent, however, was their onetime Republican co-author, Lindsey Graham (SC), who walked away from the effort amid partisan wrangling over the legislative calendar. So, after all the delays and setbacks and suspense, what’s in the bill?
(Mother Jones, May 12, 2010)
Read the rest of the entry here.
Baby Coral Home In By Sound
How do baby coral find a new home in the open ocean? They listen – very closely—for reef sounds.
Scientists at the University of Bristol in England had already discovered in the last few years that baby fish who live among coral use sound to find the reefs. So they decided to check out the coral larvae themselves. These are tiny creatures, the size of a flea.
The researchers created so-called choice chambers. When the chambers were silent, the larvae floated about, equally distributed. But when the scientists played sounds of reefs, featuring the murmurs of fish and crustaceans, the larvae swarmed towards the speakers.
(Scientific American, May 17, 2010)
Read the rest of this entry here.