Is DNA Repair a Substitute For Sex?

Bdelloid rotifers seem to get along just fine without sex. What’s more, they have done so over millions of years of evolution, resulting in at least 370 species. These hardy creatures somehow escape the usual drawback of asexuality – extinction!

Bdelloid rotifers have been able to give up sex and survive because they have evolved an extraordinary efficient mechanism for repairing harmful mutations to their DNA.

In animals that do have sex, DNA repair is accomplished during meiosis, when chromosomes pair up (one from the father, one from the mother) and “fit” genes on one chromosome can serve as templates to repair damaged genes on the other chromosome. The bdelloid, though, always seems to reproduce asexually, by making a clone of itself. How then, does it cope with deleterious mutations?

Scientists demonstrated the enormous DNA repair capacity of bdelloid rotifers by zapping them with ionizing radiation (gamma rays), which has the effect of shattering its DNA into many pieces. “We kept exposing them to more and more radiation, and they didn’t die and they didn’t die and they didn’t die,” says Mark Welch. Even at five times the levels of radiation that all other animals are known to endure, the bdelloids were able to continue reproducing.

Philodina roseola

The bdelloids’ DNA repair capacity probably evolved due to a different environmental adaptation – tolerance of extreme dryness. Bdelloids, which live in ephemeral aquatic habitats such as temporary freshwater pools and on mosses, are able to survive complete desiccation (drying out) at any stage of their life cycle. They just curl up and go dormant for weeks, months, or years, and when water becomes available, they spring back to life. Desiccation, like ionizing radiation, breaks up the rotifers’ DNA into many pieces. Presumably, the same mechanisms they use to survive desiccation as part of their life cycle also protect them from ionizing radiation.

Extreme Resistance of Bdelloid Rotifers to Ionizing Radiation.2008. Gladyshev, E., and M. Meselson . Proc. Natl. Acad. Sci. 105 (13): 5139-5144.

Evidence for degenerate tetraploidy in bdelloid rotifers. 2008. Mark Welch, D.B., J.L. Mark Welch and M. Meselson. Proc. Natl. Acad. Sci. 105 (13): 5145-5149.

Died This Day: Hermann Rorschach

Watchmen & Rorschach © DC Comics

Rorschach (Nov. 8, 1884 - April 2, 1922) was a Swiss psychiatrist who devised the inkblot test that bears his name and that is widely used clinically for diagnosing psychopathology. His secondary-school nickname was Kleck, meaning "inkblot," because of his interest in sketching.

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In 1917, he learned of Szyman Hens, who had studied the fantasies of his subjects using inkblot cards. Rorschach began in 1918 using 15 accidental inkblots, asking patients, "What might this be?" He knew the human tendency to project interpretations and feelings onto ambiguous stimuli. The subjective responses of his subjects enabled him to distinguish among them on the basis of their perceptive abilities, intelligence, and emotional characteristics. His published results (1921) drew little interest until after his death. link

Jack Kirby Explains The Origin of Mankind

The Eternals created by Jack Kirby & © Marvel Comics

Jack Kirby retold the origin of the Earth and the evolution of Mankind more than once in his career as he introduced his wild new concepts to the comic book reading world. Here’s his take from ‘The Eternals’:

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Jack explains what it's all about:

Read it all in the next issue of, "THE ETERNALS!"

Read Jack's "Origin of Homo mermanus"

The Hardness of Squid Beaks

Abstract: The beak of the Humboldt squid Dosidicus gigas represents one of the hardest and stiffest wholly organic materials known. As it is deeply embedded within the soft buccal envelope, the manner in which impact forces are transmitted between beak and envelope is a matter of considerable scientific interest

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Challengers of the Unknown © DC Comics

Here, we show that the hydrated beak exhibits a large stiffness gradient, spanning two orders of magnitude from the tip to the base. This gradient is correlated with a chemical gradient involving mixtures of chitin, water, and His-rich proteins that contain 3,4-dihydroxyphenyl-L-alanine (dopa) and undergo extensive stabilization by histidyl-dopa cross-link formation.

These findings may serve as a foundation for identifying design principles for attaching mechanically mismatched materials in engineering and biological applications.

The Transition from Stiff to Compliant Materials in Squid Beaks. 2008. Ali Miserez et al. Science 319: 1816-1819.

Living Upside-Down Shapes Spiders for Energy Saving

Art by Frank Cho

Researchers investigating spider species which live, feed, breed and ‘walk’ in an upside-down hanging position have found that their lifestyle drives a shape in spiders that confers high energy efficiency, as in oscillatory pendulums.

The great majority of land animals evolved legs capable of supporting the weight of their whole bodies, enabling them to move around with their heads above their feet. However, many spider species found it more convenient to literally turn their world upside down. They spend most of their lives hanging suspended by their legs, and ‘walk’ by swinging under the influence of gravity.

One of the focal questions was the evolutionary importance of ‘bridging’ – the technique many spiders use to move between remote plants by building their own silk bridges, which they cross by ‘walking’ suspended upside-down from them. Earlier research by other authors indicated that for monkeys this suspensory way of locomotion might be a more energetically efficient way of transportation than ‘regular’ walking on the ground.

“We discovered that spiders that live upside-down have evolved disproportionately longer legs relative to ‘normal’ spiders, which enables them to move faster while bridging than while ‘normally walking’ on the ground. Particularly ‘clumsy’ walkers are larger spiders, because their long legs – otherwise so convenient for bridging – do not allow an easy lifting of their relatively large body mass” says Dr. Jordi Moya-Laraño from Spain, the principal investigator on this project.





These results have implications for the evolution and ecology of spiders. For example, small spiders that hang from their webs should be able to leave their webs in search for prey by walking on the ground, as found in some tiny spiders, something that large spiders will be unable to do efficiently. link

Ref: Morphological Evolution of Spiders Predicted by Pendulum Mechanics. 2008. Jordi Moya-Laraño et al. PLOS One e1841.

New Organic Molecule Discovered in Space

Art by Vaughn Bode and Larry Todd

Researchers from the Max Planck Institute for Radio Astronomy in Bonn have detected for the first time a molecule closely related to an amino acid: amino acetonitrile. The organic molecule was found in the "Large Molecule Heimat", a giant gas cloud near the galactic centre in the constellation Sagittarius.

The « Large Molecule Heimat » is a very dense, hot gas clump within the star forming region Sagittarius B2. In this source of only 0.3 light-year diameter, which is heated by a deeply embedded newly formed star, most of the interstellar molecules known to date have been found, including the most complex ones such as ethyl alcohol, formaldehyde, formic acid, acetic acid, glycol aldehyde (a basic sugar), and ethylene glycol.

Starting from 1965, more than 140 molecular species have been detected in space, in interstellar clouds as well as in circumstellar envelopes. A large fraction of these molecules is organic or carbon-based. A lot of attention is given to the quest for so-called "bio"-molecules, especially interstellar amino acids. Amino acids, the building blocks of proteins and therefore key ingredients for the origin of life, have been found in meteorites on Earth, but not yet in interstellar space.

Amino acetonitrile (NH2CH2CN)

The simplest amino acid, glycine (NH2CH2COOH), has long been searched for in the interstellar medium but has so far not been unambiguously detected. Since the search for glycine has turned out to be extremely difficult, a chemically related molecule was searched for, amino acetonitrile (NH₂CH₂CN), probably a direct precursor of glycine.

"Finding amino acetonitrile has greatly extended our insight into the chemistry of dense, hot star-forming regions. I am sure we will be able to identify in the future many new, even more complex organic molecules in the interstellar gas. We already have several candidates!" says Karl Menten, director at the Max Planck Institute for Radioastronomy. link

Just as long as they don't find, "The Green Slime"....!

Fear that Freezes the Blood in Your Veins

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"The blood froze in my veins" or "My blood curdled" – these common figures of speech can be taken literally, according to the latest studies. For it turns out that intense fear and panic attacks can really make our blood clot and increase the risk of thrombosis or heart attack.

Earlier studies showed that stress and anxiety can influence coagulation.A Bonn-based research team around Franziska Geiser (from the Clinic and Policlinic for Psychosomatic Medicine and Psychotherapy) and Ursula Harbrecht (from the Institute of Experimental Haematology and Transfusion Medicine) have been the first to conduct a very careful examination of coagulation in patients with anxiety disorders.

In the coagulation system two mechanisms operate that are indispensable to life and normally work in opposite directions, each counterbalancing the other. First, coagulation involves a thickening of the blood so that a plug can form and prevent excessive bleeding from damaged vessels. Second, there is "fibrinolysis", a process that keeps the blood fluid and breaks down clots. In the case of the anxiety-disorder patients, however, the researchers observed through close analysis of the blood an activation of coagulation accompanied by an inhibition of fibrinolysis. For these types of patients, the coagulation system goes out of balance as the coagulation tendency rises – possibly with dangerous consequences. In extreme cases the imbalance can lead to blockage of a coronary artery.

The increased coagulation tendency could, says Franziska Geiser, be the "missing link" that explains why anxiety patients have a statistically higher risk of dying from heart disease by a factor of 3 or 4. link

Sterankos' Batman

The Jam & Batman's Theme Song:

Neanderthals The Result of Genetic Drift

New research adds to the evidence that chance, rather than natural selection, best explains why the skulls of modern humans and ancient Neanderthals evolved differently. The findings may alter how anthropologists think about human evolution.

The study builds on findings from a study he and his colleagues published last year in the Journal of Human Evolution, in which the team compared cranial measurements of 2,524 modern human skulls and 20 Neanderthal specimens. The researchers concluded that random genetic change, or genetic drift, most likely account for the cranial differences.



In their new study, Weaver and his colleagues crunched their fossil data using sophisticated mathematical models -- and calculated that Neanderthals and modern humans split about 370,000 years ago. The estimate is very close to estimates derived by other researchers who have dated the split based on clues from ancient Neanderthal and modern-day human DNA sequences.



The close correlation of the two estimates -- one based on studying bones, one based on studying genes -- demonstrates that the fossil record and analyses of DNA sequences give a consistent picture of human evolution during this time period.



"A take-home message may be that we should reconsider the idea that all morphological (physical) changes are due to natural selection, and instead consider that some of them may be due to genetic drift," Weaver said. "This may have interesting implications for our understanding of human evolution." link

Close correspondence between quantitative-and molecular-genetic divergence times for Neandertals and modern humans. 2008. T. D. Weaver et al. PNAS, published on-line March 17, 2008.

Lobby cards from, "Creatures That Time Forgot".

Premiered This Day (1968): Barbarella

From the Jean-Claude Forest Home Page:

Jean-Claude Forest created the character of Barbarella for V-Magazine in 1962, at the request of its editor, Georges H. Gallet, who was already familiar with Forest's work as France's premier science fiction cover artist and had commissioned an illustrated version of Catherine L. Moore's classic story Shambleau in 1955.

Barbarella was published in book for by Eric Losfeld's publishing company Le Terrain Vague in 1964, became an immediate runaway bestseller and was soon translated in a dozen countries, including by Grove Press in the United States. Not long after, it was adapted into a 1968 motion picture, produced by Dino de Laurentiis, directed by Roger Vadim, and starring Jane Fonda, for which Forest acted as design consultant.

A Forest Barbarella design from the abandoned Nelvana animation project:

Dave Stevens (1955-2008)

Dave Stevens passed away today. Best known for creating and illustrating "The Rocketeer", Dave was a exquisite artist who specialized in 'good girl' art.

Marc Evanier has some nice words about him HERE.

All images from The Grand Comic Book Database.

The Search for A Primordial Dimension

Virgil Finley from goldenagecomicbookstories.blogspot.com

The universe as we currently know it is made up of three dimensions of space and one of time, but researchers are exploring the possibility of an extra dimension.

“The idea we’re exploring is that the universe has an imperceptibly small dimension (about one billionth of a nanometer) in addition to the four that we know currently,” Kavic said. “This extra dimension would be curled up, in a state similar to that of the entire universe at the time of the Big Bang.”

The group is looking for small primordial black holes that, when they explode, may produce a radio pulse that could be detected here on Earth. These black holes are called primordial because they were created a fraction of a second after the beginning of the universe.

A Virginia Tech group is preparing to set up an Eight-meter-wavelength Transient Array radio telescope in Montgomery County to search the sky for these radio pulses from explosions up to 300 light years away. They have a similar telescope in southwestern North Carolina that has been looking for events for several months. link

Diffractive Hygrochromic Effect of the Strongest Creature in the World!

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The Hercules Beetle is remarkable, not only for its strength, able to carry up to 850 times its own weight, the protective outgrowth of the insects’ exoskeleton, also changes from green to black as its surrounding atmosphere gets more humid.

Researchers from the University of Namur in Belgium have used the latest imaging techniques to study the shell of the beetle - a scanning electronic microscope to determine the structure responsible for the colour and a spectrophotometer to analyze how the light interacts with this structure.

The light interferes with the structure to produce the green colour of the shell. When water penetrates through the widely-open porous layers, it destroys the interferences phenomenon leading to a black colouration.

As to why the beetle changes colour, question marks also remain. Some have suggested that it is to do with protection – it becomes more humid at night and is therefore good for cover to turn black. Others have suggested that it is to do with warmth absorption at night. Questions remain.

Marie Rassart, who did the research at the University of Namur, said, “The sort of structural behaviour displayed by the Hercules Beetle could be an important property for ‘intelligent’ materials’. Such materials could be put to work as humidity sensors. This could be useful for example in food processing plants to monitor the moisture level.” link

Diffractive hygrochromic effect in the cuticle of the hercules beetle Dynastes Hercules. 2008. M Rassart et al 2008 New Journal of Physics: (14pp).

Steranko Interviews Conan The Barbarian

Story & Art © Steranko
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From an old issue of Jim Steranko's Mediascene comes this 'interview' with Conan.

Discovered This Day: The Former Planet Pluto

In 1930, the planet Pluto was discovered by Clyde Tombaugh, the only planet to be found by an American astronomer, after three decades of work at Lowell Observatory in Flagstaff, Arizona. Before Tombaugh was born, Percival Lowell had searched unsuccessfully for Pluto, a ninth planet whose gravity would explain deviations in the positions of Uranus and Neptune. In his will he decreed that the hunt should continue. That meant using a telescope to photograph tiny pieces of the sky by night, then and sifting through the millions of star images by day for one dim dot that moved. When Lowell Observatory director Vesto Slipher hired him, a Kansas farmboy, Clyde Tombaugh threw himself into the search in Apr 1929. From Today In Science History.

The above picture captures the true colors of Pluto as well as the highest surface resolution so far recovered. Although no spacecraft has yet visited this distant world, the New Horizons spacecraft launched early this year is expected to reach Pluto in 2015. The above map was created by tracking brightness changes from Earth of Pluto during times when it was being partially eclipsed by its moon Charon. Pluto's brown color is thought dominated by frozen methane deposits metamorphosed by faint but energetic sunlight. The dark band below Pluto's equator is seen to have rather complex coloring, however, indicating that some unknown mechanisms may have affected Pluto's surface. Info from HERE

More info HERE.