Oct
07
2013

Enrolled trilobite: The trilobite's strategy of rolling itself up into a ball for protection dates back to some of its earliest known ancestors in the fossil record. This fossil trilobite (Isotelus?) was found in Late Ordovician shale in St. Paul, Minnesota.
Enrolled trilobite: The trilobite's strategy of rolling itself up into a ball for protection dates back to some of its earliest known ancestors in the fossil record. This fossil trilobite (Isotelus?) was found in Late Ordovician shale in St. Paul, Minnesota.Courtesy Mark Ryan
A new study appearing in Biology Letters shows that trilobites - everyone's favorite prehistoric water bug - developed an effective survival strategy much earlier than previously thought.

Trilobite fossils from Early Cambrian rock formations in the Canadian Rockies and elsewhere lend evidence that some of the earliest trilobites used enrollment (i.e rolling themselves up into a ball like an armadillo) to protect themselves from predators or the environment. Trilobite fossils found here in Minnesota are several million years younger dating back to the Late Cambrian through Late Ordovician Periods (500 - 430 mya) and are often found enrolled. It was an effective survival strategy.

Trilobites were arthropods, which meant they possessed exoskeletons, segmented bodies and jointed appendages. Their closest extant relative is the horseshoe crab. Trilobite bodies - for the most part - were comprised of a head (cephalon) positioned on a body (thorax) that was divided into three lobes: essentially an axial dividing a left and right pleura, and a tail (pygidium). The mouth (hypostome) was located on the underside. It's thought that most early trilobites were predators and/or scavengers who spent their lives roaming the sea floors looking carcasses, detritus or living prey to feed upon. Most trilobites possessed complex eyes (although some were eyeless). Like other arthropods (e.g. today's lobsters), trilobites would outgrow their exoskeletons, discarding them (molting) as they grew in size or changed shape. Their newly exposed soft skin soon hardened into a new, tough, outer casing. Once hardened, their segmented exoskeletons (composed of calcium carbonate) were ventrally flexible, giving them the ability to roll up into a ball should they need sudden protection from whatever threatened them.

Some early trilobite forms from Middle Cambrian-aged fossils had been viewed as incapable of enrolling but the new research based on much older fossils found in mudstones in the Canadian Rockies in Jasper Park pushes back the origins of the strategy to some of the earliest trilobites to appear in the fossil record (Suborder Olenellus). These appeared 10-20 million years earlier at the very beginnings of the Cambrian Period and show evidence of having already developed the ability to enroll.

Trilobites in some form or another existed across a span of more than 270 million years, a very successful run by any measure. The enrollment strategy certainly contributed to their longevity. Although trilobites were already in decline, the last of their kind were wiped out in the great extinction event that marked the end of the Permian Period and the start of the Triassic. They weren't the only casualty of the extinction: nearly 90 percent of Earth's species were terminated along with them.

Even though trilobites are extinct (they died out in the Permian Mass Extinction along with around 90 percent of Earth's species) they were an extremely successful and adaptable life form. No wonder they remain today a favorite among fossil collectors.

SOURCE and LINKS
Paper at Biology Letters
Major Trilobite features
A Guide to the Orders of Trilobites

Tyrannosaurus rex: remains of the Tyrant Lizard King on display at the Royal Tyrrell Museum in Drumheller, Alberta.
Tyrannosaurus rex: remains of the Tyrant Lizard King on display at the Royal Tyrrell Museum in Drumheller, Alberta.Courtesy Mark Ryan
One hundred and eight years ago, on October 5th, vertebrate paleontologist Henry Fairfield Osborn bestowed upon a collection of recently discovered fossil bones one of the greatest names in the annals of dinosaur and binomial nomenclature: Tyrannosaurus rex!

Oct
02
2013

Gravity: Do they get the science right in the new action film Gravity?
Gravity: Do they get the science right in the new action film Gravity?Courtesy Wikipedia
Film goers will have the chance to travel through space this weekend with the blockbuster movie "Gravity" hitting the theaters. Its a ficticious story about two American astronauts dealing with disaster during a space shuttle mission.

I've come to expect Hollywood to place loose and easy with actual science when it comes to movies with scientific themes. And then today I stumbled upon this article in Time by Jeffrey Kluger, the co-author, with astronaut Jim Lovell, of Lost Moon: The Perilous Voyage of Apollo 13, which was the basis of the Apollo 13 movie released in 1995.

He applies his extensive space knowledge to fact check what's depicted in the new George Clooney/Sandra Bullock film. Here's his analytical summary: "So, that’s a lot that Gravity gets wrong. But you know what? So what? The shuttle, space station and spacesuits are painstakingly recreated; the physics of moving about in space—thrusts requiring counterthrusts, spins requiring counterspins, the hideous reality that if you do go spiraling off into the void your rotation never, never stops—are all simulated beautifully, scarily and accurately."

Click on the link above to get detailed analysis of what's scientifically right and wrong with Gravity.

Have you seen the film? What do you think about its accuracy in portraying the science of living and traveling in space?

This is surprising on a couple levels.

Do you like hot weather? Do you like playing with graphs? Combine those two interests in at this interactive website that charts the fluxuation in global temperature over your own personal lifetime.

Sep
30
2013

Spider Web
Spider WebCourtesy Wikimedia - en:User:Fir0002
Eden Steven, a physicist at Florida State University is developing ways to possibly conduct electricity using spider webs and carbon nanotubes.

A carbon nanotube is a one-atom thick sheet of carbon that’s been rolled into a tube. A nanotube’s diameter is at least 10,000 times smaller than a strand of human hair. Carbon nanotubes are strong and have been found to conduct electricity and heat.

Florida State University reports Steven used just a drop of water to attach powdery carbon nanotubes onto spider silk. He gathered the spider silk himself, using a stick to gather webs outside his lab.

The experiment has drawn much national attention. “It turns out that this high-grade, remarkable material has many functions,” Steven said of the silk coated in carbon nanotubes. “It can be used as a humidity sensor, a strain sensor, an actuator (a device that acts as an artificial muscle, for lifting weights and more) and as an electrical wire.”

Steven wanted to investigate eco-friendly materials and was especially interested in materials that could deal with humidity without complicated treatments and chemical additives.

“Understanding the compatibility between spider silk and conducting materials is essential to advance the use of spider silk in electronic applications,” Steven wrote in the online research journal Nature Communications. “Spider silk is tough, but becomes soft when exposed to water. … The nanotubes adhere uniformly and bond to the silk fiber surface to produce tough, custom-shaped, flexible and electrically conducting fibers after drying and contraction.”

To learn more about Eden Steven's work visit:
http://www.magnet.fsu.edu/mediacenter/news/pressreleases/2013/2013septem...

To learn more about nanotechnology, science, and engineering, visit:
www.whatisnano.org

To see other nano stories on Science Buzz tagged #nano visit:
http://www.sciencebuzz.org/buzz_tags/nano

Sep
28
2013

A lake carrier heads out on Lake Superior from Duluth: As with the world's oceans, researchers have now detected plastic pollution in all the Great Lakes.
A lake carrier heads out on Lake Superior from Duluth: As with the world's oceans, researchers have now detected plastic pollution in all the Great Lakes.Courtesy Mark Ryan
Over the past couple years, Science Buzz has posted several stories (here and here) about the humongous patches of garbage and plastic debris found floating in the world's oceans. It's a serious problem and one that should raise red flags for anyone concerned with the Earth's environment. But even more troubling is the recent news that plastic particles have now been found in all five of the Great Lakes lining the border of the USA and Canada. Unlike the large globs of plastic clogging areas of the ocean, the plastics polluting the Great Lakes are microscopic particles detectable only in a microscope. But they're no less disturbing.

A team of researchers led by Dr. Sherri “Sam” Mason, professor of chemistry at SUNY-Fredonia has been gathering water samples and reported finding high concentrations of plastic particles in the chain of freshwater lakes. One of the researchers involved is environmental chemist Lorena Rios-Mendoza from University of Wisconsin-Superior. Both she and Mason have studied the Great Trash Island (aka Trashlantis) in the Pacific Ocean but has now turned their attention to the Great Lakes.

Most of the plastic found in the water is visible only under a microscope, but has been found in all five of the Great Lakes, both in the water column, and in lake sediment. The amount of micro-plastic varies between lakes with Lake Erie - the shallowest and smallest by water volume - containing the largest ratio and Lake Superior - the largest and most voluminous - a much smaller ratio. But it doesn't matter; the point is that we're polluting some of our important sources of fresh water with plastic.

It's thought that cosmetics with could one of the sources, since the industry relies heavily on using micro-beads in its products. These tiny plastic particles used on our faces, skin, and teeth, eventually get washed off into the water supply where they're too small to get filtered out. But cosmetics certainly aren't the only source. Plastic refuse obliterates the shoreline in Haiti
Plastic refuse obliterates the shoreline in HaitiCourtesy tedxgp2
Think of the ungodly amount of plastic material we use and discard every year. Surprisingly, only about five percent of the bags, bottles, cups, electronics, etc. get recycled; most plastic trash ends up in landfills where it slowly degrades and eventually finds its way into the world's favorite garbage dump: the oceans.

“We have no idea how long some of these plastics stay in the ocean, could be more than 40 years,” Rios-Mendoza said. She also worries if organic toxins in the water can attach themselves to the tiny plastic particles, and end up in the food chain. In this regard, Rios-Mendoza has been sampling Great Lake fish to see if such toxic particles are present in their guts.

It's important to remember that only 3 percent of the world's water is freshwater and the five Great Lakes - Superior, Huron, Michigan, Ontario, and Erie - together contain 20 percent of that freshwater. That's a large portion of a relatively scarce and essential life ingredient. Last fall, I posted an interesting graphic that illustrates nicely Earth's total water supply versus fresh water and puts things in perspective.

Lake Superior: Plastic pollutants have now invaded the upper Great Lake.
Lake Superior: Plastic pollutants have now invaded the upper Great Lake.Courtesy Mark Ryan
Rios-Mendoza and Mason have been collaborating with a research and education group called 5Gyres Institute that monitors and studies garbage patches found in five subtropical gyres in the world's oceans. Rio-Mendoza presented a preliminary study of their work on the Great Lakes at a recent meeting of the American Chemical Society. The team's future studies involve pinpointing the sources of plastic pollution and acquiring a better understanding of how plastics degrade in the environment.

"We all need to become aware of how much plastic we use in our lives and avoid using single-use products. Don’t buy water in plastic bottles or cosmetic products with micro beads. Bring re-usable bags to the store with you. Simple things like this make a big difference, but it’s also important to keep talking about this issue and raising awareness about how it affects the Great Lakes and the world’s oceans.” --- Dr. Sherri Mason“

By the way, here in Minnesota, and situated at the western tip of Lake Superior, the city of Duluth was recently proclaimed to have the best tasting drinking water in the state. By best-tasting, I'm assuming they mean it has no taste whatsoever since water is described as a colorless, tasteless liquid. Whatever the case, I always thought Duluth's drinking water was the best while growing up there (my grandparents lived in a Twin Cities' suburb and I never liked the taste of their softener-treated water).
In another water-related story, it's estimated that life on Earth can survive for at least another 1.75 billion years until we move out of the habitable zone and our oceans (and other water sources) will evaporate in the increased heat. So it's probably best that we take care of what water we have - it needs to sustain us for a long time.

SOURCE and LINKS
National Geographic story
Red Orbit story
The World's Largest Dump
The Great Pacific garbage patch
Star Tribune story on Duluth's water

Signs of Curiosity's work at the Rocknest site: Soil samples taken and analyzed from this site have been found to contain Martian water.
Signs of Curiosity's work at the Rocknest site: Soil samples taken and analyzed from this site have been found to contain Martian water.Courtesy NASA/JPL-Caltech/MSSS
After last week's disappointing news that no signs of current life have been found living on Mars, NASA scientists have just confirmed some pretty exciting news: the Mars rover, Curiosity, has found water on the Red Planet. Analysis of dirt and fine soil scooped up from the Rocknest site on the surface of Mars has revealed that it contains water. This is big news. Read here what NASA has to say about it.

Going down: A golden eagle was captured on camera attacking a deer in Russia.
Going down: A golden eagle was captured on camera attacking a deer in Russia.Courtesy WSI
A camera trap in Russia was set up to capture the movements of tigers. What researchers found one day was much different: three images showing a golden eagle taking down a deer running in the snow. You can read all about it here along with seeing enlarged versions of these fairly graphic images. The sika deer being attacked is estimated to be around 90 to 100 pounds. The linked story also goes into good detail about the grisly events that transpired at the scene (also captured on camera) after the eagle left.

Kristi Curry Rogers: turned her childhood passion for dinosaurs into a career as a vertebrate paleontologist. She's seen here talking about her work with titanosaurs to the Geological Society of Minnesota.
Kristi Curry Rogers: turned her childhood passion for dinosaurs into a career as a vertebrate paleontologist. She's seen here talking about her work with titanosaurs to the Geological Society of Minnesota.Courtesy Mark Ryan
Are you like me? Has your passion for paleontology remained with you beyond your childhood fascination with dinosaurs and fossils? Do you still yearn to become a paleontologist and uncover the next great sauropod discovery or rare trilobite fossil? Paleontology's not a particularly easy field to get into - and the jobs aren't as numerous as you'd hope - but it can be done. Amy Atwater is a blogger and paleontology intern (like me!) and lists ten things you can do to fulfill your paleo aspirations. Her advice is aimed more toward the female side of the gender spectrum (her column is part of the Huffington Post's Girls in STEM series) but her tips are useful to just about anyone who wishes to pursue a career in the fascinating science of fossils and ancient life.

More about STEM