Science News Update: April 12th

April 12 sci news 3

Science News for the Science Classroom

Skewed Bird Gender Ratios

Humans aren’t the only species to face relationship problems. In a recent study of 187 bird species, scientist found that populations which exhibit skewed gender ratios- more males than females, or vice versa- are more likely to result in divorce, infidelity, or polygamy in mated pairs.

While 90% of bird species remain monogamous for life, having one gender more popular than another can break these norms. In populations with more females than males, divorce is twice as more likely to occur than in populations with more males. Consequently, male-dominated populations practice infidelity more often. In both cases, the rarer sex tends to be more susceptible to practicing polygamy.

Interestingly enough, these relationship behaviors featured in correlate surprisingly close to humans’ behaviors in similar population disparities.

Link: http://goo.gl/soFHDz

Why Do Zebras Have Stripes?

It’s an age old question: why do zebras have stripes? Hypothesis have varied, from being used as camouflage to confusing predators to reducing body temperature, but a new study seems to point in a different direction: that Zebras evolved striped to ward away biting insects.By using a model that compares the seven living species of the equid group- including horses, asses, and zebras- researchers discovered that the presence of striping directly correlates with the number of biting flies in an environment.

While this is a huge step in figuring out the mystery behind a Zebra’s stripes, scientists are still unsure exactly how these stripes ward away flies, in part because Zebras are notoriously difficult to thoroughly study in the wild.

Read more: http://goo.gl/FM7n6d

The Oceans of Enceladus

Not too long ago, it was believed that Earth was the only body in the solar system with liquid water and, therefore, the only planet capable of harboring life. Recent evidence has proved otherwise: from the dried riverbeds and lakes that prove that water once flowed on Mars to the oceans that lie beneath Europa’s ice, liquid water- and the possibility of life- is becoming more and more prevalent in our solar neighborhood. Now, another moon of Saturn, tiny Enceladus, may very well be our best candidate for extraterrestrial life.

After witnessing plums of water-vapor ejecting from “tiger stripe” formations on Enceladus’ south pole, Scientists at NASA have concluded the presence of an ocean the size of lake Superior trapped beneath the ice of the frozen moon. Even more exciting is that fact that the plums ejected from Enceladus’ tiger stripes contain organic molecules. Should the moon’s interior be warm enough, microbial life isn’t out of the picture.

Learn more here: http://goo.gl/RyaSnb

RicochetScience Article: Endeladus and Water – What this Means for Life

The Microbe That (Almost) Killed All Life

250 million years ago, the Permian extinction resulted in the loss of 90%of ocean species and nearly 70% of land-dwelling species, making it the closest life has ever come to being completely eradicated on planet Earth. Theories have ranged from a gamma ray burst to intense volcanic activity, though the true culprit may be much smaller: small enough to be invisible to the naked eye.

Methanosarcina is a member of a group of single-celled organisms called archaea – organisms that are adapted for life in extreme environments. While it had been present before the Permian extinction, sometime around 250 million years ago it developed the ability to produce methane, probably borrowing the ability from another kind of microbe through a process known as “gene transfer”. Methanosarcina would go on to explode in the ocean biome, releasing massive amounts of methane into the atmosphere and making the planet inhospitable to almost all life.

Methanosarcina may explain why the Permian mass extinction lasted nearly ten thousand years, as opposed to the relatively short extinction period that occurred after the dinosaur’s own demise by the hands of an asteroid.

Link: http://goo.gl/vuEFTZ

Black Death Airborne?

The Black Death- or the bubonic plague- hit London in 1349, killing 6 out of every 10 people. It’s perhaps the most devastating disease in human history, yet according to the findings of at least a few scientists, our commonly held beliefs that the disease was carried by fleas living on rats may be completely false.

While researching several newly uncovered bodies of plague victims from London’s 1349 outbreak and comparing them to a recent outbreak of bubonic plague in Madagascar, these scientists found that the DNA of the plague strains were exactly the same, over 600 years later. Because of this, they determined that a flea-borne disease could not have spread so fast as the Black Death that ravaged London. The plague, therefore, would have to be pneumonic- airborne- rather than bubonic. Rats and fleas would have very little to do with the plague’s spread.

The findings are still rather controversial, but at the very least it is an interesting theory that sheds a different light on the nature of the Black Death.

Read more here: http://goo.gl/c8xZIg

Human Sense of Smell is Better than Predicted

How good is your sense of smell? Scientists used to say that people could smell over 10,000 different scents. They were definitely right with the over part because they have now found that we can smell over one trillion scents!

It may not always seem like we can smell that many different things because different molecules are mixed together making one final scent. Yet, each molecule has its own scent when apart!

link: http://goo.gl/Xs15ER

Videos

This week we released the third part of our Mendelian genetics tutorials – The Dihybrid Cross. This short video explains the basic principles of a two-trait cross with an emphasis on probability. You can view the entire set of videos from our Biology 101 page.

 

For more science news, follow us on Twitter and FlipBoard.

This article was edited on April 15th to correct for a statement that Methanosarcina possessed a nucleus.

Enceladus and Water – What This Means for Life

Scientists at the California Institute of Technology recently announced that they have evidence of water on Saturn’s tiny moon Enceladus. And not only is there water, it is probably liquid water.

How can this be possible on an object that is almost 900 million miles away from the Sun (about 10 times the Earth-Sun distance) and has a temperature of – 201 degrees Celsius (-330 degrees F) ? The answer has to to with gravity. Enceladus is small – its diameter is only 310 miles – and it is caught in a gravitational battle between massive Saturn and the moon Dione. This basically warps the surface of Enceladus, producing enough heat to liquify the water in its center. Enceladus is not unique in this regard, scientists have long suspected that there is water on Jupiter’s moon Europa, and that it is liquid water due to the gravitational tug-of-war between Europe and Jupiter.

Since 2005 scientists have know about the possibility of water on Enceladus when they discovered plumes of ice coming from the southern surface of the planet. Within the ice were molecules of carbon dioxide and methane. Carbon compounds, and energy source, and liquid water are the prime ingredients for life.

water plumes on Enceladus

NASA / JPL-Caltech

So how much water is there? Remember that Enceladus is small – but the initial research suggests that there is a sea about the size of Lake Superior located in the southern hemisphere. This sea is located between an ice covering (about 20 miles thick) and the rocky core of the planet (see the artist rendition below). It is estimated that this sea may be about 6 miles deep, providing plenty of water for the evolution of life.

art of Enceldadus interiot

Image courtesy of JPL-NASA

Why is Water Important?

Water has a special relationship with life. It is an excellent solvent, it is both cohesive and adhesive, and it regulates changes in temperature. In fact, we haven’t found any evidence of life yet on Earth that isn’t based on water. While that does not mean that there aren’t examples out there somewhere in the Universe, it does allow us a starting point with which to begin our search for life outside of Earth.

For a quick review, here is our video on the properties of water:

So what is next? While we are actively searching Mars for signs of life that most likely went extinct millions of years ago, there is a possibility that life, or maybe just he early forms of life, may be underneath the ice at Enceladus. Seems like that warrants a look.

Additional Resources

  •  Iess L., Stevenson D.J., Parisi M., Hemingway D., Jacobson R.A., Lunine J.I., Nimmo F., Armstrong J.W., Asmar S.W. & Ducci M. & (2014). The Gravity Field and Interior Structure of Enceladus, Science, 344 (6179) 78-80. DOI:

Video: Punnett Squares and the Monohybrid Cross

We have prepared two new videos as part of our Biology 101 series of content. Both of these videos provide a quick introduction to Mendelian genetics and focus on how to determine simple genotypic and phenotypic ratios.

Both of these videos are also located on our YouTube Channel.

Understanding the Punnett Square

The Punnett square is often used to  visualize the phenotypic and genotypic ratios of simple Mendelian crosses. In this quick video, we present how to set up and interpret a Punnett square for a single-trait cross.

YouTube Link: http://youtu.be/wAPpKtwOayk

Understanding a Single-Trait (Monohybrid) Cross

The second video explore a one-trait Mendelian cross. In this example we are using the flower color of pea plants, since these traits are what are most often used in classes to describe a one trait cross. In this example we are using parents that are heterozygous for the trait, and therefore this is also an example of a monohybrid cross.

YouTube Link: http://youtu.be/rKE-HX3v50g

For more resources, check out our Biology 101 project which contains additional articles and videos. You can also follow Ricochet Science on YouTube.

Looking for something specific, or have a general idea for a video? Use our Contacts page to let us know.

Science News Update: March 16th

Science News March 16th

Science News for the Science Classroom

Pygmy Tyrannosaur

Tyrannosaurine dinosaurs, the gargantuan carnivores native to the Late Cretaceous and popularized by the infamous T. Rex, have traditionally only been discovered in North America and Asia. Nanuqsaurus hoglundi, the “Pygmy Tyrannosaur”, is the most recent species of this group to be discovered. Related both to both Tarbosaurus and TyrannosaurusN. hoglundi was found not in China or the United States but in Alaska, making it the first tyrannosaurine species yet known to live in arctic climates.

While Alaska may not have been as cold as it is now 70 million years ago, it still would have featured the extreme seasonal differences that characterize the state today. Because of these varying conditions, N. hoglundi developed to be much smaller than its more southern cousins. For instance, N. hoglundi’s skull measures only 25 inches, whereas the legendary T. Rex sports a skull some 60 inches long. The “Pygmy Tyranosaur” may also have been influenced by geographical isolation, with the ancient Brooks Range separating it from other dinosaur species.

As the N. hoglundi fossil was found in fragments, it was believed to belong to a different, non-tyrannosaurine species before recently being re-classified as a new kind of Dinosaur.

Read more here: http://goo.gl/jTzFY7

Second Child ‘Cured’ of HIV

In recent years, claims that people have been “cured” of HIV/AIDS have surfaced in the media. From the Berlin patient, who through a bone marrow transplant cured both his leukemia and his AIDS, to the “Mississippi Baby”, who was born HIV positive but when administered high dosages of certain drugs had the virus eliminated from its system. Now, a second baby has been rid of HIV, through much the same way as the Mississippi baby.

The baby, born in Long Beach, California, was born HIV positive from a likewise HIV positive mother who had not had antiretoviral therapy. When doctors administered three drugs- AZT, 3T and Nevirapine- into the baby’s system, the virus apparently went into remission. Scientists believe this is because the virus, at such an early stage in the child’s life, had not had time to spread to the viral reservoirs that allow the HIV virus to survive the lifetime of its host.

The baby is still on antiretroviral treatment, so it is unknown if the virus is truly gone, yet 8 months after the procedure it has yet to retain any traces of HIV in its blood.

Link: http://goo.gl/gsG2Mg

“Lost Years” of Sea Turtles Uncovered

The first two years of life for a sea turtle have remained a mystery for scientists for years. What we know is that they are dangerous years- only 1% of the 50 to 250 eggs a female sea turtle lays survives into adulthood. While trackers have been proposed to help understand these “lost years”, until recently such technology has been too large to be put on juvenile turtles.

A recent study conducted by the University of Central Florida raised 17 baby turtles to the ages of 3.5-9 months old, when they had grown large enough to fit the trackers onto their backs. From there, they released the turtles into the open ocean and studied the courses they took.

All of the Sea Turtles turned north along the Gulf Stream upon release, some traveling as far as the Azores near Portugal, with most (but not all) eventually turning east towards North Carolina. The Sea Turtles also spent all of their time on the surface, presumably to keep warm.

Read more: http://goo.gl/4uKE6H

Black Hole Spinning Half the Speed of Light

In the first measurement of a black hole’s rotational speed, a “quasar” 6 billion light years away has been measured at spinning half the speed of light. While more measurements of the speeds of other black holes is needed to determine if this speed is the norm for supermassive black holes or an outlier, it is believed that the more often a black hole eats, the faster it spins. In the case of RX J1131-1231, this rate is close to one stellar mass per year.

While RX J1131-1231 should be too far away to accurately measure, scientists were able to determine its speed through a technique called “gravitational lensing”, in which a closer galaxy, in this case one 3 billion years away, “magnifies” the galaxies directly behind it. Scientists believe that this technique can be used to determine the speeds of even more distant and massive black holes.

Learn more: http://goo.gl/Fgpgne

 

Videos

Drones have far more uses than for war or delivering Amazons packages- like studying volcanoes! In this video, a Phantom drone gets closer to an erupting volcano than a human ever could.

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Science News Update: March 9th

science news march 3rd

Science News For The Science Classroom

Artificial muscles made of fishing wire

While artificial muscles are hardly a new idea, they are often made out of incredibly expensive materials, such as carbon nanotubes, making them infeasible to develop commercially. New innovations, however, may have just removed that cost barrier, creating artificial muscles at merely $5 a kilogram- out of fishing wire.

These new artificial muscles are 100 times stronger than human sinew, and can develop 7.1 horsepower per kilogram- proportionally the same power as a jet engine.

In addition to their potential to be used for prosthetic limbs and military or industrial exoskeletons, the nature of these cheap, powerful muscles can allow for more expressive and realistic robotic faces and can even be used in clothing, creating pores that expand or contract depending on outside temperatures.

Read more: http://goo.gl/PfPbhu

Dogs process voices in the same way as humans

It may not surprise dog owners that dogs develop emotional connections to what they hear, but for scientists, the findings of a new study conducted in Hungary have allowed for a much better understanding of the minds of our canine companions.

In the experiment, 11 dogs, made up of border collies and golden retrievers, were trained to sit in an MRI while being subjected to several auditory signals- from a dog whining to a human laughing. Likewise, 22 humans were subjected to the same signals while the MRI measured corresponding blood flow in their brain.

In both species, the brain reacted in similar ways to differences in emotion- whining vs. playful parking or laughing vs. scolding. While some scientists claim that this is a result of dogs molding their brains to human domestication, most believe these findings to suggest that emotional context evolved in a shared ancestor to both dogs and humans, which probably lived around 100 million years ago.

If this is the case, than many more animals besides dogs could share the same emotional connection to speech.

Link: http://goo.gl/UT2ckg

New materials help wounds heal faster

Growth factors are the proteins that allow us to heal.  When we get a cut or a bruise, these proteins signal certain cells to help heal the wounds, and for nearly a decade, scientists have been trying to figure out how to manipulate these growth factors to help wounds heal faster and more efficiently.

Researchers in Switzerland have come one step closer in developing such a growth factor substance. By encouraging growth factor proteins to “stick” to wounds, the researchers managed to quickly heal the wounds of several lab mice with genetic traits that made wounds difficult to heal.

While growth factor substances are still new to the market, the work of these scientists could one day allow for growth factors to be cheaper, more efficient, and require less material to work.

Learn more here: http://goo.gl/WGhTsM

Using Silk to Heal Bones

Traditionally, doctors treat broken bones by inserting metal “fixation devices” that help the bone heal back to its original form. Yet these fixation devices often come with disadvantages, such as causing unnecessary stress on the broken bone or even causing inflammation and infection. Metal fixation devices also have to be sometimes removed via a second surgery, causing stress and placing financial burden on the patient.

In yet another advance in medicine this week, scientists have developed a new kind of fixation device, made not of metal but of the silk of the B. mori silkworm. In addition to being more efficient at healing bones, these silk fixation devices carry less risk of infection and, most importantly, biodegrade within the human body, ridding the need for follow-up surgery.

Link: http://goo.gl/B27wSn

World’s Largest Virus

It used to be thought that all viruses were incredibly small- so small that they could never be seen under a typical microscope. Yet, in recent years, so-called “Megaviruses” and “Pandoraviruses” that are up to 100 times larger than typical viruses have been discovered. Luckily, however, these huge viruses are only a threat to single-celled organisms, as they lack the complicated entry mechanisms that allow smaller viruses to enter the more complex cells that humans and other animals possess.

What’s interesting, then, about the latest megavirus discovered, is not just it’s huge size- the largest yet recorded, at over 100 times the size of a normal virus- but how ancient it is. Discovered in permafrost in Siberia, Pithovirus sibericum is nearly 30,000 years old, having “survived” 100 meters beneath the ice for thousands of years before re-emerging to feed on its single-celled prey.

As viruses are not truly alive, they also cannot really die- as evident by sibericum‘s incredible age. It’s probably that viruses, therefore, could live for millions of years until their DNA breaks down.

Link: http://goo.gl/lK8BQs

Placing a Severe Winter in Perspective

For Eastern America, it may seem as if this January set records for cold temperatures, however, it was the 4th warmest January for earth as a whole! It was cold in certain areas, but the US does not have a ton of say in the global temperatures.

The rest of the earth was actually warmer than normal despite Eastern America’s nasty January.

Link: http://goo.gl/l1KY3G

Videos

Olympic Records

Since 1894, there have been 32 Olympic games. With the best athletes in the world competing each year, one would think that records would start to “plateau”, with few if any records being made as the Olympics progressed. Yet each year, new records are being made- is this because humans are naturally becoming better at sports, or is something else at play?

Olympic Physiology: The Toll of Competition

The winter Olympics serve as a showcase for some of the finest athletes in the world. Many of the winter events involve sports that are unusually demanding on the human body. Take the case of Evegeni Plushenko, the Russian hope for gold in men’s figure skating.

Rus-nat-ep

The Russian men’s and women’s teams have long been a dominant force in figure skating and the decision was made to go with Plushenko despite the fact that he was considered quite old at age 31. The Russians hoped his long experience at 4 Olympic games and multiple medal wins would put him in position to win again even after undergoing painful surgery to replace a disc in his back with a synthetic one. Plushenko’s final chance at glory was cut short when he was forced to withdraw from Olympic competition due to the pain of years of injuries finally catching up with him.

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