Human evolution, alcohol and chemistry


This video is called African Animals Getting Drunk From Ripe Marula Fruit.

By Bob Yirka today:

Study shows pre-human ancestors adapted to metabolize ethanol long before humans learned about fermentation

19 hours ago

(Phys.org)—A team of researchers in the U.S. has found evidence to support the notion that our pre-human ancestors were able to metabolize ethanol long before our later ancestors learned to take advantage of fermentation—to create alcoholic beverages. In their paper published in Proceedings of the National Academy of Sciences, the team describes how they genetically sequenced proteins from modern primates and used what they found to work backwards to discover just how long ago our ancestors have been able to metabolize ethanol.

Humans have been consuming beverages that make them tipsy, drunk and/or sick for a very long time, of that there is little doubt. But why do we have the ability to metabolize ethanol in the first place? That’s what the team set out to answer. They began by sequencing an enzyme called ADH4—it’s what’s responsible for allowing us to metabolize ethanol. Other have it as well, but not all metabolize ethanol as well as we do. By sequencing ADH4 found in a 28 including 17 that were primates, the team was able to create a family tree of sorts based on ethanol metabolizing ability. The team then tested those sequences for their metabolizing ability by synthesizing nine kinds of the ADH4 enzyme. Doing so showed the researchers that most early primates had very little ability to metabolize ethanol for most of their early history.

Then, about 10 million years ago, some of the ancestors of modern humans suddenly were able to do a much better job of it, while others that diverged and led to apes such as orangutans, did not. This discovery led the team to wonder what might have occurred to cause this to come about. They note that other evidence has shown that around this same time, the planet cooled slightly, making life a little more difficult for our tree dwelling ancestors. They suggest they began climbing down out of the trees to eat the fruit that fell, which gave them a food advantage and a reason for developing the ability to metabolize —otherwise they would have become too drunk from eating the fermenting fruit to defend themselves or live otherwise normal lives. If true, the theory would also offer a major clue as to why our became terrestrial.

Explore further: Study unlocks secret of how fruit flies choose fruit with just the right amount of ethanol

More information: Hominids adapted to metabolize ethanol long before human-directed fermentation, PNAS, Matthew A. Carrigan, DOI: 10.1073/pnas.1404167111

Abstract

Paleogenetics is an emerging field that resurrects ancestral proteins from now-extinct organisms to test, in the laboratory, models of protein function based on natural history and Darwinian evolution. Here, we resurrect digestive alcohol dehydrogenases (ADH4) from our primate ancestors to explore the history of primate–ethanol interactions. The evolving catalytic properties of these resurrected enzymes show that our ape ancestors gained a digestive dehydrogenase enzyme capable of metabolizing ethanol near the time that they began using the forest floor, about 10 million y ago. The ADH4 enzyme in our more ancient and arboreal ancestors did not efficiently oxidize ethanol. This change suggests that exposure to dietary sources of ethanol increased in hominids during the early stages of our adaptation to a terrestrial lifestyle. Because fruit collected from the forest floor is expected to contain higher concentrations of fermenting yeast and ethanol than similar fruits hanging on trees, this transition may also be the first time our ancestors were exposed to (and adapted to) substantial amounts of dietary ethanol.

Shame-faced crabs of the Pacific


This video from the sea near Samal island in the Philippines is about a shame-faced crab, eating a Terebra maculata mollusk.

From Australian Geographic:

Shame-faced crab has nothing to hide about

November 27, 2014

It may look like its hiding its face out of embarrassment, but this crab has everything to be proud of

by Becky Crew

I DON’T THINK I’ve ever loved another crab as much as I love this crab right now. He’s so embarrassed he can barely even look at us. He’s so ashamed that he has to cover his face with his two humungous front pincers. Don’t feel bad, shame-faced crab, we don’t care what you did; you’re just a crab.

Found at depths of up to 50m below the surface of the Indo-Pacific, these large crabs range as far as Madagascar to west, Japan to the north, and throughout Indonesia, Papua New Guinea and New Caledonia a little closer to home.

Despite their looks and their funny little name, shame-faced crabs (Calappa calappa) are no victims. These highly armoured creatures are like walking tanks, their 15cm-long, burnt-caramel-coloured carapace acting as the perfect cover from predators until they have a chance to bury themselves right into the sand. Watch the video [above], it’s almost a little creepy how it inches deeper and deeper into the ocean floor, until all that’s left is a pair of beady eyes and the upper edges of its jagged pincers, looking just like a monster face peering up at you.

Shame-faced crabs don’t have to worry too much about predators, but keep themselves hidden during the day all the same. At night they turn to hunting, targeting little mollusks such as clams, oysters and sea snails. While hard-shelled prey like these present a challenge to many would-be predators, the shame-faced crab has evolved to deal with them expertly.

Of its two huge, meaty pincers, the right one is perfect for cracking into its prey’s tough outer shell. It’s equipped with a single, specially curved tooth that works with the flat surface of the pincer just like a can-opener to cut into its prey. Then the left pincer, which is longer, smaller, and sharper, takes over to extract the flesh from inside.

Being elegant about how you eat your dinner is nothing to be ashamed about, shame-faced crab. Just because the rest of the ocean is filled with barbaric rubes that wouldn’t know a utensil if it landed on them. Chin up, little man!

Coconut crabs in Hawaii: here.

Organic molecules discovery on comet


This 13 November 2014 video is called Rosetta Comet Landing: Philae send first image of 67P.

From daily The Guardian in Britain:

Philae lander detects organic molecules on surface of comet

Spacecraft beams back evidence of carbon and hydrogen that could provide clues about origins of life on Earth

Richard Gray

Tuesday 18 November 2014 22.58 GMT

The Philae lander has found organic molecules – which are essential for life – on the surface of the comet where it touched down last week.

The spacecraft managed to beam back evidence of the carbon and hydrogen–containing chemicals shortly before it entered hibernation mode to conserve falling power supplies.

Although scientists are still to reveal what kind of molecules have been found on comet 67P/Churyumov-Gerasimenko, the discovery could provide new clues about how the early chemical ingredients that led to life on Earth arrived on the planet.

Many scientists believe they may have been carried here on an asteroid or comet that collided with the Earth during its early history.

The DLR German Aerospace Centre, which built the Cosac instrument, confirmed it had found organic molecules.

It said in a statement: “Cosac was able to ‘sniff’ the atmosphere and detect the first organic molecules after landing. Analysis of the spectra and the identification of the molecules are continuing.”

The compounds were picked up by the instrument, which is designed to “sniff” the comet’s thin atmosphere, shortly before the lander was powered down.

It is believed that attempts to analyse soil drilled from the comet’s surface with Cosac were not successful.

Philae was able to work for more than 60 hours on the comet, which is more than 500m miles from Earth, before entering hibernation.

“We currently have no information on the quantity and weight of the soil sample,” said Fred Goesmann principal investigator on the Cosac instrument at the Max Planck Institute for Solar System Research.

Goesmann said his team were still trying to interpret the results, which will hopefully reveal whether the molecules contain other chemical elements deemed important for life.

Professor John Zarnecki, a space scientist at the Open University who was the deputy principal investigator on another of Philae’s instruments, described the discovery as “fascinating”.

“There has long been indirect evidence of organic molecules on comets as carbon, hydrogen and oxygen atoms have been found in comet dust,” he said.

“It has not been possible to see if these are forming complex compounds before and if this is what has been found then it is a tremendous discovery.”

Organic molecules, which are chemical compounds that contain carbon and hydrogen, form the basic building blocks of all living organisms on Earth.

They can take many forms from simple small molecules like methane gas to complex amino acids that make up proteins.

Philae landed on comet 67P/Churyumov–Gerasimenko after a 10-year journey through space aboard the Rosetta space probe. Philae’s initial attempt to touch down on the comet’s surface were unsuccessful when it failed to anchor itself properly, causing it to bounce back into space twice before finally coming to rest.

It meant the lander’s final resting place was about half a mile from the initial landing site and left Philae lying at an angle and its solar panels partially obscured.

In a desperate attempt to get as much science from the lander as possible before its meagre battery reserves ran out, scientists deployed a drill to bore down into the comet surface.

It is thought, however, that the drilling was unsuccessful and it failed to make contact with the comet.

But other findings from instruments on the lander, which were beamed back shortly before it powered down into a hibernation mode, suggest that the comet is largely composed of water ice that is covered in a thin layer of dust.

Preliminary results from the Mupus instrument, which deployed a hammer to the comet after Philae’s landing, suggest there is a layer of dust 10-20cm thick on the surface.

Beneath that is very hard water ice, which Mupus data suggests is possibly as hard as sandstone.

“It’s within a very broad spectrum of ice models. It was harder than expected at that location, but it’s still within bounds,” said Professor Mark McCaughrean, senior science adviser to Esa.

“You can’t rule out rock, but if you look at the global story, we know the overall density of the comet is 0.4g/cubic cm. There’s no way the thing’s made of rock.”

At Philae’s final landing spot, the Mupus probe recorded a temperature of –153°C before it was deployed and then once it was deployed the sensors cooled further by 10°C within half an hour.

“If we compare the data with laboratory measurements, we think that the probe encountered a hard surface with strength comparable to that of solid ice,” said Tilman Spohn, principal investigator for Mupus. Scientists hope that as comet 67P/Churyumov-Gerasimenko moves closer to the sun in the next few months, some light will start to reach Philae’s solar panels again, giving it enough power to come out of hibernation.

This could allow further analysis to take place on the surface.

“Until then we are going to have to make do with the data we have got,” said Zarnecki.

The Philae spacecraft may not be dead quite yet.

Why autumn leaves are colourful


This video is called Why Leaves Change Color: Untamed Science.

From eNature Blog in the USA:

What Makes Autumn’s Leaves So Colorful?

Posted on Monday, October 06, 2014 by eNature

Sometime between now and the middle of November, the trees in North America’s eastern broadleaf forests will reach their full fall glory.

From Vermont’s Northeast Kingdom and New Hampshire’s White Mountains to the Shenandoah Valley and beyond, leaf peepers will bring traffic to a standstill on beautiful fall weekends. By the carful and busload, they’ll come to gawk at the beautiful countryside.

But what will they be seeing? How do leaves end up in such spectacular colors?

Hidden Colors

Leaf color arises from various chemicals within trees. It’s the strength as well as the presence or absence of compounds like tannins, xanthophylls, and carotenes that determines fall hues in the scores of tree species found in the East.

Back in the spring and summer, when the millions of trees in these same woodlands were busily growing and producing food, their leaves were chock full of chlorophyll, and it was the chlorophyll that colored the forests varying shades of green. But chlorophyll is a mask, and once trees sense the change in the weather and start to stop chlorophyll production, the mask drops and the other colors of the leaves come to the forefront.

A Color For Every Tree

The fall colors can be so distinctive in some tree species that it’s possible to identify these trees from a distance merely by noting their hues. The brilliant red leaves belong to the Red Maple, American Mountain Ash, and Black Tupelo, plus sumacs, blueberries, and Virginia Creeper in the understory. Richer red foliage is typical of Red Oak, Scarlet Oak, and White Oak. Birches and beeches sparkle with bright yellow foliage, while Witch Hazel and Striped Maple are a less intense yellow, and walnuts, hickories and aspens attain a truly golden glow.

Of course, not all trees settle on a single color. Sugar Maples, for example, blaze in green, yellow, orange, and startling red, and Sassafras comes in various shades of red, orange, yellow, and purple.

If you want to enjoy the fall colors yourself, plan ahead and, if possible, venture out during the week as opposed to on a crowded weekend.

No matter when you go, though, spend a little time outside your car. The trees are even prettier close-up, along a quiet trail or down a less traveled side road.

Have you had time to enjoy Fall’s colors this year?

We always enjoy hearing about your experiences.

New orchid species discoveries on Azores volcano


This shows details of the flowers of Hochstetter's Butterfly-orchid, a newly recognized and exceptionally rare orchid recently discovered on the Azorean island of São Jorge. Credit: Richard Bateman

From LiveScience:

New Orchid Species Found on ‘Lost World’ Volcano in the Azores

By Douglas Main, Staff Writer

December 10, 2013 07:32am ET

For years, there was only one formally recognized species of orchid on the Azores, a cluster of volcanic islands west of Portugal, though some claimed there were two species. However, a recent, three-year study to describe these Azorean flowers found that three species of orchids exist on the islands, including two that are newly recognized.

One of the new species was found atop a remote volcano and is arguably Europe’s rarest orchid, said Richard Bateman, a botanist at Kew Royal Botanic Gardens in London. Researchers were surprised to find the new species atop the volcano, which had “a really ‘Lost World’ feel to it,” he told LiveScience.

The orchids likely originate from a single species that arrived by seed millions of years ago. They soon developed smaller flowers, unlike their ancestors, which had large blooms. The most widespread orchid on the island, the short-spurred butterfly orchid (Platanthera pollostantha), is known for these small flowers, Bateman said. [Photos: The Orchids of Latin America]

Analysis of other orchids found on the islands soon turned up another species, known as the narrow-lipped butterfly orchid (Platanthera micrantha).

But then scientists happened upon an even rarer and more striking orchid, with large flowers, like those of the plants’ ancestors. “In a sense, evolution has reversed itself,” Bateman said. This species, now known as Platanthera azorica or Hochstetter’s butterfly orchid, was originally collected more than 170 years ago, but hadn’t been further studied or recognized as a unique species.

Mónica Moura, a researcher at the University of the Azores, happened upon the flower, and noticed it was different. “I immediately recognized the flowers as being exceptionally large for an Azorean butterfly orchid,” Moura said, according to a release describing the study.

The new species require urgent conservation; the International Union for Conservation of Nature, a global environmental organization, currently lumps all of these into a single species, which is incorrect, Bateman said.

The two rare orchids are threatened by invasive species and habitat destruction, Bateman said. Much of the unique dwarf forests that once covered the Azores—and in which the rare orchids are found—have been destroyed by inefficient dairy farming and other development, Bateman added.

Like many other orchids, the two rare orchid species have symbiotic relationships with fungi that allow them to survive. Without a certain type of fungi, the seeds can’t germinate, Bateman said. It’s possible these rare species can only survive in the presence of a single fungal species, which helps them germinate and supplies them with nutrients as adult plants, he said. More widespread species can likely partner with a variety of fungi, he added.

Blind mole-rats resistant to cancer


This video is called Spalax microphthalmus, Mole-Rat.

Today, there was news about “deaf” frogs which turned out to be not really deaf.

Now, about blind mole-rats which turn out to be blind indeed; however, they turn out to have other strong points.

From the University of Illinois at Urbana-Champaign in the USA today:

Blind mole-rats are resistant to chemically induced cancers

Like naked mole-rats (Heterocephalus gaber), blind mole-rats (of the genus Spalax) live underground in low-oxygen environments, are long-lived and resistant to cancer. A new study demonstrates just how cancer-resistant Spalax are, and suggests that the adaptations that help these rodents survive in low-oxygen environments also play a role in their longevity and cancer resistance.

The findings are reported in the journal Biomed Central: Biology.

“We’ve shown that, compared to mice and rats, blind mole-rats are highly resistant to carcinogens,” said Mark Band, the director of at the University of Illinois Biotechnology Center and a co-author on the study. Band led a previous analysis of in blind mole-rats living in low-oxygen (hypoxic) environments. He found that genes that respond to hypoxia are known to also play a role in aging and in suppressing or promoting cancer.

“We think that these three phenomena are tied in together: the hypoxia tolerance, the longevity and ,” Band said. “We think all result from to a .”

Unlike the naked mole-rat, which lives in colonies in Eastern Africa, the blind mole-rat is a solitary rodent found in the Eastern Mediterranean. Thousands of blind mole-rats have been captured and studied for more than 50 years at Israel‘s University of Haifa, where the animal work was conducted. The Haifa scientists observed that none of their blind mole-rats had ever developed cancer, even though Spalax can live more than 20 years. Lab mice and rats have a maximum lifespan of about 3.5 years and yet regularly develop spontaneous cancers.

To test the blind mole-rats’ cancer resistance, the Haifa team, led by Irena Manov, Aaron Avivi and Imad Shams, exposed the animals to two cancer-causing agents. Only one of the 20 Spalax tested (an animal that was more than 10 years old) developed after exposure to one of the carcinogens. In contrast, all of the 12 mice and six rats exposed to either agent developed cancerous tumors.

The team next turned its attention to fibroblasts, cells that generate extracellular factors that support and buffer other cells. Previous studies of naked mole-rat cells have found that fibroblasts and their secretions have anti-cancer activity. Similarly, the researchers at Haifa found that Spalax fibroblasts were efficient killers of two types of breast and two types of lung cancer cells. Diluted and filtered liquid medium drawn from the fibroblast cell culture also killed breast and lung cancer cells. Mouse fibroblasts, however, had no effect on the cancer cells.

To help explain these results, Band and his colleagues looked to the gene expression profiles obtained from their previous studies of blind mole-rats in hypoxic environments. The researchers had found that genes that regulate DNA repair, the cell cycle and programmed cell death are differentially regulated in Spalax when exposed to normal, above-ground oxygen levels (21 percent oxygen) and conditions of hypoxia (3, 6 and 10 percent oxygen). These changes in gene regulation differed from those of mice or rats under the same conditions, the researchers found.

Spalax naturally have a variant in the p53 gene (a transcription factor and known tumor suppressor), which is identical to a cancer-related mutation in humans, Band said. Transcription-factor genes code for proteins that regulate the activity of other genes and so affect an animal’s ability to respond to its environment. The research group in Israel showed “that the Spalax p53 suppresses apoptosis (programmed cell death), however enhances cell cycle arrest and DNA repair mechanisms,” he said.

Hypoxia can damage DNA and contribute to aging and cancer, so mechanisms that protect against hypoxia – by repairing DNA, for example – likely also help explain the blind mole-rat’s resistance to cancer and aging, Band said.

“So now we know there’s overlap among the genes that affect DNA repair, hypoxia tolerance and suppression,” he said. “We haven’t been able to show the exact mechanisms yet, but we’re able to show that in Spalax they’re all related. One of the lessons of this research is that we have a new model animal to study mechanisms of disease, and possibly discover new therapeutic agents.”

Explore further: The naked mole-rat’s secret to staying cancer free

More information: “Pronounced Cancer Resistance in a Subterranean Rodent, the Blind Mole-Rat, Spalax: In Vivo and In Vitro Evidence,” www.biomedcentral.com/1741-7007/

Scientists have been fascinated by the long lives of the nearly hairless, big-toothed rodents known as naked mole rats that live in the Horn of Africa. The animals have lifespans of up to 31 years, which is decades longer than would be expected for something of their size. By comparison, for instance, mice live for four years at most: here.

Ice Age ocean life and iron


This video says about itself:

NASA | Earth Science Week: The Ocean’s Green Machines

“The Ocean’s Green Machines” is Episode 3 in the six-part series “Tides of Change”, exploring amazing NASA ocean science to celebrate Earth Science Week 2009.

One tiny marine plant makes life on Earth possible: phytoplankton. These microscopic photosynthetic drifters form the basis of the marine food web, they regulate carbon in the atmosphere, and are responsible for half of the photosynthesis that takes place on this planet. Earth’s climate is changing at an unprecedented rate, and as our home planet warms, so does the ocean. Warming waters have big consequences for phytoplankton and for the planet.

From Woods Hole Oceanographic Institution in the USA:

Scientists solve a 14,000-year-old ocean mystery

At the end of the last Ice Age, as the world began to warm, a swath of the North Pacific Ocean came to life. During a brief pulse of biological productivity 14,000 years ago, this stretch of the sea teemed with phytoplankton, amoeba-like foraminifera and other tiny creatures, who thrived in large numbers until the productivity ended—as mysteriously as it began—just a few hundred years later.

Researchers have hypothesized that iron sparked this surge of ocean life, but a new study led by Woods Hole Oceanographic Institution (WHOI) scientists and colleagues at the University of Bristol (UK), the University of Bergen (Norway), Williams College and the Lamont Doherty Earth Observatory of Columbia University suggests iron may not have played an important role after all, at least in some settings. The study, published in the journal Nature Geoscience, determines that a different mechanism—a transient “perfect storm” of nutrients and light—spurred life in the post-Ice Age Pacific. Its findings resolve conflicting ideas about the relationship between iron and biological productivity during this time period in the North Pacific—with potential implications for geo-engineering efforts to curb climate change by seeding the ocean with iron.

“A lot of people have put a lot of faith into iron—and, in fact, as a modern ocean chemist, I’ve built my career on the importance of iron—but it may not always have been as important as we think,” says WHOI Associate Scientist Phoebe Lam, a co-author of the study.

Because iron is known to cause blooms of biological activity in today’s North Pacific Ocean, researchers have assumed it played a key role in the past as well. They have hypothesized that as Ice Age glaciers began to melt and sea levels rose, they submerged the surrounding continental shelf, washing iron into the rising sea and setting off a burst of life.

Past studies using sediment cores—long cylinders drilled into the ocean floor that offer scientists a look back through time at what has accumulated there—have repeatedly found evidence of this burst, in the form of a layer of increased opal and calcium carbonate, the materials that made up phytoplankton and foraminifera shells. But no one had searched the fossil record specifically for signs that iron from the continental shelf played a part in the bloom.

Lam and an international team of colleagues revisited the sediment core data to directly test this hypothesis. They sampled GGC-37, a core taken from a site near Russia’s Kamchatka Peninsula, about every 5 centimeters, moving back through time to before the biological bloom began. Then they analyzed the chemical composition of their samples, measuring the relative abundance of the isotopes of the elements neodymium and strontium in the sample, which indicates which variant of iron was present. The isotope abundance ratios were a particularly important clue, because they could reveal where the iron came from—one variant pointed to iron from the ancient Loess Plateau of northern China, a frequent source of iron-rich dust in the northwest Pacific, while another suggested the younger, more volcanic continental shelf was the iron source.

What the researchers found surprised them.

“We saw the flux of iron was really high during glacial times, and that it dropped during deglaciation,” Lam says. “We didn’t see any evidence of a pulse of iron right before this productivity peak.”

The iron the researchers did find during glacial times appeared to be supplemented by a third source, possibly in the Bering Sea area, but it didn’t have a significant effect on the productivity peak. Instead, the data suggest that iron levels were declining when the peak began.

Based on the sediment record, the researchers propose a different cause for the peak: a chain of events that created ideal conditions for sea life to briefly flourish. The changing climate triggered deep mixing in the North Pacific ocean, which stirred nutrients that the tiny plankton depend on up into the sea’s surface layers, but in doing so also mixed the plankton into deep, dark waters, where light for photosynthesis was too scarce for them to thrive. Then a pulse of freshwater from melting glaciers—evidenced by a change in the amount of a certain oxygen isotope in the foraminifera shells found in the core—stopped the mixing, trapping the phytoplankton and other small creatures in a thin, bright, nutrient-rich top layer of ocean. With greater exposure to light and nutrients, and iron levels that were still relatively high, the creatures flourished.

“We think that ultimately this is what caused the productivity peak—that all these things happened all at once,” Lam says. “And it was a transient thing, because the iron continued to drop and eventually the nutrients ran out.”

The study’s findings disprove that iron caused this ancient bloom, but they also raise questions about a very modern idea. Some scientists have proposed seeding the world’s oceans with iron to trigger phytoplankton blooms that could trap some of the atmosphere’s carbon dioxide and help stall climate change. This idea, sometimes referred to as the “Iron Hypothesis,” has met with considerable controversy, but scientific evidence of its potential effectiveness to sequester carbon and its impact on ocean life has been mixed.

“This study shows how there are multiple controls on ocean phytoplankton blooms, not just iron,” says Ken Buesseler, a WHOI marine chemist who led a workshop in 2007 to discuss modern iron fertilization. “Certainly before we think about adding iron to the ocean to sequester carbon as a geoengineering tool, we should encourage studies like this of natural systems where the conditions of adding iron, or not, on longer and larger time scales have already been done for us and we can study the consequences.”