forget me not [smile]

Saturday, October 19, 2013

This skull may have just rewritten the book on human evolution

by Robert T. Gonzales

It’s a discovery that could change our understanding of early humans. An incredibly well-preserved, 1.8-million-year-old skull from Dmanisi, Georgia suggests the evolutionary tree of the genus Homo may have fewer branches than previously believed.

A detailed analysis of the skull (above, in situ, and at left, fully excavated), appears in the latest issue of Science. In their report, the researchers – led by Georgian anthropologist David Lordkipanidze – write that it is “the world’s first completely preserved hominid skull.” And what a skull it is. It suggests that the earliest known members of the Homo genus (H. habilis, H. rudolfensis and H. erectus) may not have been distinct, coexisting species, at all. Instead, they may have been part of a single, evolving lineage that eventually gave rise to modern humans.

Discovered alongside the remains of four other early human ancestors, all of which date to roughly 1.8-million years ago, “Skull 5,” as the specimen is called, has a relatively tiny brain case and a protruding lower jaw – anatomical features reminiscent of Australopithecus, a more primitive human ancestor. And yet, its upper jaw resembles that of a 2.3-million-year-old specimen from Ethiopia, thought to have belonged to H. habilis; its bulky browline bears a strong resemblance to that of H. erectus; and its long, vertically oriented upper face and the overall shape of its braincase are unmistakably Homo. An anatomical chimera, Skull 5 possesses a surprising combination of features that have never before been observed together in an early Homo fossil…

(read more: io9)

Sea Level Rise Swamping Florida’s Everglades

by Becky Oskin

Rising sea levels are transforming the Florida Everglades, a new study shows. Plant communities that thrive in salt water are expanding along the coast, leaving less room for plants that depend on fresh water.

Salt-loving mangroves in the Everglades have marched inland in the past decade, while freshwater plants — such as saw grass, spike rush and tropical hardwood trees — lost ground, according to a study published in the October 2013 issue of the journal Wetlands…

(read more: Live Science)

image by CSTARS / Doug Fuller

Ancient fish face shows roots of modern jaw

Primitive vertebrate’s sophisticated mandible rewrites evolutionary tree.

by Eliot Barford

“It may be hard to see, but you seem to share a family resemblance with Entelognathus primordialis. The fish, which lived 419 million years ago in an area that is now part of China, is the earliest known species with a modern jaw.

Entelognathus primordialis is a new addition to the placoderms, a class of armour-plated fishes that lived from about 430 million to 360 million years ago. Like most vertebrates, including mammals, placoderms had a bony skull and jaw, but most of them had simple beak-like jaws built out of bone plates. Palaeontologists have traditionally believed that the fishes’ features bore no relation to ours.

They assumed that the placoderm face was lost to evolutionary history, and most thought that the last common ancestor of living jawed vertebrates had no distinct jawbones — that it was similar to a shark, with a skeleton made mostly of cartilage and at most a covering of little bony plates. The theory went that the bony fishes evolved later, independently developing large facial bones and inventing the ‘modern’ jaw. Such fishes went on to dominate the seas and ultimately gave rise to land vertebrates.

But findings published today in Nature¹ may turn that view on its head. Min Zhu, a palaeontologist at the Chinese Academy of Sciences’ Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, and his colleagues describe E. primordialis from a fossil that is much better preserved than most placoderms. It has what looks like a bony fish’s jaw, even though it is older than the earliest known sharks and bony fishes” (read more).

(Source: Nature)

nicotine

Nicotine acts on neurons of the mesolimbic reward system in the midbrain.

A burning cigarette quickly converts from a tobacco storehouse to a chemical factory, producing some 4,000 compounds. Of these, 400, including nicotine and carbon monoxide, are toxins, and another 40 are carcinogens.

Nicotine itself is distilled at the tip of the burning cigarette. There it is absorbed onto tar (particulate matter) droplets that are carried deep into the lungs with each intake of smoke. Nicotine’s trip from the lungs to the brain takes about 10 seconds.

After it reaches the brain, nicotine, in its pharmacologically active levorotatory form, (S)-nicotine, shanghais receptor sites on neurons normally activated by the natural nerve-tonerve messenger acetylcholine. (These are called cholinergic receptors.) And by impersonating acetylcholine, nicotine alters the way the brain processes information.

In the brain, nicotine becomes one of nature’s chemical chameleons. It acts on the reward system to cause the release of dopamine—and that makes people feel good. It acts through other brain chemicals thought to be important for activating and alerting systems. And it acts on still other systems that are probably involved in cognition and motivation.

"Nicotine is a pretty amazing drug. If it didn’t kill you, it would be pretty terrific," says Edythe D. London, chief of the National Institute on Drug Abuse’s (NIDA) neuroimaging and drug action branch.

It’s also “an unusually insidious addictive drug,” declares Avram Goldstein, Stanford University professor emeritus of pharmacology and author of “Addiction: From Biology to Drug Policy.” It calms and it stimulates. It affects mood, appetite, and cognition. Many smokers claim smoking helps them handle stress and boredom, control their weight and appetite, and function better in unfamiliar social situations.

How can a single molecule do all these things? Using a fascinating array of research tools, trained laboratory animals, and exotic compounds, scientists are plumbing the depths of the brain in search of answers.

-Lois R. Ember

The Nicotine Connection: Scientists are teasing out the chemistry of nicotine addiction as tobacco firms and government regulators tussle over possible controls on cigarettes

Chemical & Engineering News, November 28, 1994

Jules Cloquet

cloud photographs

Thursday, October 17, 2013

The World’s Most Beautiful Wastewater Treatment Plant

by Chris Tackett

Let this wastewater treatment plant show you how to live.

This may sound crazy, but it is exactly why the Omega Institute for Holistic Studies in Rhinebeck, New York constructed their Omega Center for Sustainable Living (OCSL), also known as the Eco Machine. We can learn some valuable lessons from this building.

The Omega Center for Sustainable Living may be the most beautiful wastewater treatment plant in the world. It is powered by solar and geothermal power, so it requires no additional power to operate. Unlike other wastewater treatment plants, the OCSL does not use chemicals to treat the water, but rather mimics the processes of the nature world, such as using a combination of microorganisms, algae, plants and gravel and sand filtration to clean sewage water and return clean drinkable water back to the aquifer.

In addition to doing all of this, the OCSL also functions as a classroom, to help educate and inspire people about the power of nature to provide solutions…

(read more: TreeHugger)

dark matter explained

8-foot giant squid pillow

You’ll need:

2 yards of felt
1 yard of patterned fabric (I suggest a polka dot-type pattern so it looks like suction cups)
1 medium piece of black felt, 1 medium piece of white felt (for the eyes)
white thread, black thread and thread of the same color as the felt you’re using
pins
about 5 lbs. of stuffing
a couple big sheets of paper to draw your pattern

(read more)

broad bodied chaser dragonfly

A Broad-bodied Chaser (Ladona depressa) dragonfly emerges from its final molt into adulthood, Commanster, Belgium.

(photos: James K. Lindsay)

Amazon fish has super-shield against piranhas

Microscopic examination and mechanical testing have revealed the secrets of the arapaima, one of the biggest freshwater fish on the planet.

Researchers led by Robert Ritchie at the University of California at Berkeley found its scales have an ultra-tough outer shell, designed to “promote tooth fracture at the point of penetration”.

The scales also have a corrugated shape, designed to deflect pressure to a thicker, more elastic layer of collagen that lies underneath. The collagen itself is arranged in twisted overlapping layers, called lamellae, that are around 50 nanometres (50 billionths of a metre) thick.

They can slide slightly in response to a bite, causing its pressure to be spread over a wider area. The scales “are a prime example of a biological material’s evolution for a particular function”, says the paper, appearing in the journal Nature Communications…

Lamprey’s Sexy Secret? … Bile Salt

by Douglas Main

Nothing says “I’m single and ready to mingle” like a dose of salty digestive fluid. For sea lampreys, anyway.

Male sea lampreys use a type of bile salt, which is more typically known for digesting fats, to advertise their genetic fitness to females and readiness to mate, new research shows. This stands in contrast to silver lampreys, which use the enzyme for digestion and other nonsexual functions, said Weiming Li, a researcher at Michigan State University.

The research could be used to help find a way to thwart the mating habits — and thus reduce the population — of sea lampreys, an invasive species that has taken a major toll on a variety of fish species in the Great Lakes…

(read more: Live Science)