Stories tagged Life Science

Sep
27
2014

Edwards' Dodo: painted by Roelant Savery in 1626
Edwards' Dodo: painted by Roelant Savery in 1626Courtesy Public domain via Wikipedia
Death of individuals is a fact of life, and in the same way so is extinction of species. An animal species lasts, on average, about 4 million years. It's claimed that 99 percent (or more!) of all species that have ever lived on Earth are now extinct. (If you are wondering how that number was calculated, you can read a couple explanations here).

The statistic becomes more credible when you consider this interesting image compilation of every animal that's gone extinct in just the last 100 years. The death list includes not only all sorts of birds and fish, but rhinos, hippos, deer, bi-valves, bison, horses, geckos, frogs, bats, lions, tigers, and bears - oh, my! (Because of its vastness the insect world is not included in the list).

Most of the life-forms pictured have been confirmed as extinct by the International Union for the Conservation of Nature (IUCN) along with a few others from reliable sources. That's not to say some straggling thought-to-be-gone individuals won't be sighted in some obscure location in the future but until then they'll be considered extinct.

The compilation not only gives a good picture of the diversity of life on our planet but also a good idea of the fragility of the biosphere.

SOURCE and LINKS
Every animal that have gone extinct in the last century on Pixable.com.
Endangered Species International
Center for Biological Diversity

Sep
12
2014

Paleontologist Ernst Stromer: Discoverer of original Spinosaurus aegyptiacus.
Paleontologist Ernst Stromer: Discoverer of original Spinosaurus aegyptiacus.Courtesy Public domain via Wikipedia
Back in 1911, German paleontologist Ernst Stromer discovered and described the remains of a then new Cretaceous dinosaur he named Spinosaurus aegyptiacus. The strange beast sported a huge sail framed around a series of giant spines that ran down its back. Unfortunately, all Stromer's fossil evidence was destroyed during the hostilities of WW II, when the British Royal Air Force bombed the Munich museum where the fossils were stored. Only a few scientific drawings and a single photograph remain.

Ninety years later an international team of researchers led by paleontologist Nizar Ibrahim returned to Stromer's original dig site and discovered additional specimens of Spinosaurus aegyptiacus, and in studying their fossils have come to some startling new conclusions about the strange dinosaur.

Spinosaurus aegyptiacus
Spinosaurus aegyptiacusCourtesy University of Chicago Fossil Lab
Spinosaurus was a big boy - nine feet longer than the largest known Tyrannosaurus rex. And despite a long-held notion that dinosaurs were strictly terrestrial - i.e. they only dwelled on land (although like us, they probably occasionally swam in water), S. aegyptiacus appears to have spent much of his life in water, feeding on fish, and when on land (e.g to lay eggs) probably walked on all-fours, unlike every other known predatory dinosaur.

The new findings are published online on the Science Express website, and in the October issue of National Geographic.

Paul Sereno, vertebrate paleontologist at the University of Chicago and a member of the research team, explains some of the new knowledge gleaned from the newly discovered fossil bones.

SOURCES and LINKS
University of Chicago report
Science Daily story

Aug
18
2014

Hallucigenia sparsa fossil: from the Burgess Shale
Hallucigenia sparsa fossil: from the Burgess ShaleCourtesy M. R. Smith / Smithsonian Institute
One of the strangest and more mysterious critters that scurried across the Middle Cambrian seafloor has baffled paleontologist since it was first identified in the 1970s. Was it a worm? Which side was up? Did it have legs or spikes or both? Was its head actually its tail? Did it have any extant descendents or was it an evolutionary dead-end? The worm-like creature was so baffling and so bizarre, it was given the very apropos name of Hallucigenia.

The tubular, spiked-worm possessed seven or eight pairs of legs and ranged in length from 2/5th of an inch to one and 1/4 inches and looks like something out of a bad dream. Early interpretations of their fossils were all over the map. The stiff spikes on it back were first thought to be its legs, and its legs misidentified as tentacles. What was thought to be its tail ended up being its head.

Using modern imaging technology, researchers from the University of Cambridge have been closely studying fossils from the famous Burgess Shale quarry located high in the Canadian Rockies, and are uncovering Hallucigenia's secrets. By studying the claws at the end of its legs they have been able to link it to modern velvet worms (onychophorans). Scientists have long suspected the two were somehow related but until now have failed to find anything significant to prove it. By studying Hallucigenia's claws they've determined that they're constructed of nested cuticle layers, very similar to how the jaws of velvet worms are organized. The similarity is no surprise since jaws are known to have evolved from a modified set of front legs.

But besides giving Hallucigenia a place in the lineage of life on Earth, the Cambridge team during the course of their study also discovered something else: that arthropods - which include crustaceans, spiders, insects and trilobites - aren't in fact as closely related to velvet worms as previously thought.

“Most gene-based studies suggest that arthropods and velvet worms are closely related to each other," said co-author Dr Javier Ortega-Hernandez. "However, our results indicate that arthropods are actually closer to water bears, or tardigrades, a group of hardy microscopic animals best known for being able to survive the vacuum of space and sub-zero temperatures – leaving velvet worms as distant cousins.”

SOURCE and LINKS

University of Cambridge story
Previous Buzz Post on Hallucigenia
The Cambrian Explosion
More about Tartigrade

Jun
02
2014

Drosophila melanogaster: the fly.
Drosophila melanogaster: the fly.Courtesy André Karwath aka Aka via Wikipedia Creative Commons
FlyMAD could be the best thing since sliced bread. The thermo- and opto- genetic device, created by team of scientists from the Research Institute of Molecular Pathology (IMP) at Vienna University and a US lab, allows the researchers to focus visible light and heat rays onto specific regions in a fly's anatomy and manipulate the annoying insect's behavior.

Using lasers and computers, the tool can precisely target and activate certain neurons in the thorax and brain of the fruit fly Drosophila melanogaster raising its temperature and stirring up its courtship behaviors. In one test, the fly began "singing" (through rapid wing vibration) as it hit on various balls of wax. Another test turned the pesky bug into the King of Plop causing it to switch into courtship dance mode (they had one doing the moonwalk!) What's wild is that FlyMAD performed these manipulations while the erratic test subjects were on the move inside an enclosed box.

The science team, led by biologist Andrew Straw and his lab, documented the test results with video recordings, and published their findings in the journal Nature Methods.

The name FlyMAD, by the way, stands for "Fly Mind Altering Device". Can you think of a cooler name than that? Maybe this could lead to the building of a better fly-swatter.

SOURCE and LINKS

ScienceDaily.com
Straw Lab Blog
Vienna Biocenter story

Apr
17
2014

Virus Filter - The fibers of the filter are white and the virus green.
Virus Filter - The fibers of the filter are white and the virus green.Courtesy Björn Syse

Scientists have developed a paper made of cellulose nanofibers that can be used to filter out harmful viruses.

The new filter paper is made with cellulose fibers, a natural component of green plants that gives wood its strength. Cellulose is the main component of plant cell walls, and the basic building block for many textiles and for paper. Cellulose works well for filters because it is inexpensive, disposable, inert, and non-toxic; cellulose is also mechanically strong and stable in a wide range of acid and alkaline conditions.

But normal filter paper can't trap viruses. A virus is tiny, about a thousand times smaller than a human hair. Normal filter paper has pores that are too large to remove tiny viruses. The new nano fiber filter paper is made with cellulose fibers with diameters of less than 100 nanometers. Viruses range in size from 30-50 nanometers, and can be trapped in the nano fiber filter paper.

The research has been conducted at two Swedish universities, Uppsala University and Swedish University of Agricultural Sciences/Swedish National Veterinary Institute.

To read more about this research visit:
http://www.uu.se/en/media/press-release-document/?id=2271&area=3,8&typ=p...

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

Apr
13
2014

Tiktaalik roseae: Field Museum of Natural History
Tiktaalik roseae: Field Museum of Natural HistoryCourtesy Eduard Solà via Wikipedia
If you missed last week's PBS broadcast of Your Inner Fish, the documentary based on paleontologist-anatomist Neil Shubin's book by the same name, you have another chance to catch up on the first of three segments on the web. It's an excellent opening segment of the 3-part series, but is only available (for free!) right here through April 23, 2014.

The series deals with Shubin's search for the connections we all have with our fishy and reptilian ancestors. His discovery of the remarkable transitional fossil named Tiktaalik roseae on Ellesmere Island in the Canadian Arctic has added great evidence of our ties with our distant piscean relatives. The flat-headed, 375 million year-old Tiktaalik possessed the exact features - such as both lungs and gills, a wrist and neck - that you'd hope to find in a transitional form between swimming fish and land-walking tetrapods.

The next episode, titled Your Inner Reptile airs Wednesday, April 16th on your local PBS station. It's on here in the Twin Cities at 9pm but check your local listing for times in your area.

In the meantime, watch the first episode, and read about some of the reaction to Shubin's find here, here, and here.

LINKS
University of Chicago Tiktaalik roseae page

Mar
05
2014

Virus: Giant viruses are genetically more complex and about 25 percent larger.
Virus: Giant viruses are genetically more complex and about 25 percent larger.Courtesy jiparis
A husband-and-wife-led research team has announced finding an ancient virus laying dormant in Siberian permafrost for more than 30,000 years!

Jean-Michel Claverie and Chantal Abergel of Aix-Marseille University in France and their colleagues cut up pieces of permafrost samples - supplied by scientists from the Russian Academy of Science - and added them to petri dishes of amoebae only to see the one-celled animals ripped apart by unknown viruses. They isolated the attacking, larger-than-usual virus and named it Pithovirus sibericum, because of its resemblance to an earthenware jar. The permafrost samples had been collected from a frozen riverbank in Siberia in 2000.

The discovery brings the total number of known "giant viruses" to three. The extra-large viruses are about 25 percent larger than normal, genetically more complex, and composed of hardier stock.

"Among known viruses, the giant viruses tend to be very tough, almost impossible to break open," said Claverie and Abergel. "Special environments such as deep ocean sediments and permafrost are very good preservers of microbes because they are cold, anoxic and in the dark."

Two other giant viruses Mimivirus and Pandoravirus were also discovered by Claverle and Abergel in the last decade. The latter, in my opinion, is a disturbingly great name for this type of thing. But so far only the pithovirus has been observed in the laboratory infecting contemporary life forms. Luckily, none of them pose a threat to humans, but that's not to say future giant viruses thawed out of frozen environments or released by retreating ice caps won't be.

"I don't see why they wouldn't be able to survive under the same conditions," said Claverie.

Results of the research appear in the Proceedings of the National Academy of Sciences.

SOURCES and LINKS
National Geographic story
Sydney Morning Herald
More about giant viruses

Feb
21
2014

Is obesity in this baby's future?: It could depend on the yogurt's fat content.
Is obesity in this baby's future?: It could depend on the yogurt's fat content.Courtesy Clover_1
Last Christmas, my son's girlfriend introduced me to honey-flavored yogurt, a delicious concoction of creamy sweetness. I've never been a fan of yogurt, but I immediately fell in love with this stuff, and try to keep a container of it on-hand in the fridge at all times. I can't seem to get enough of it.

One of the reasons it's so tasty is because it's made with whole milk which makes it high in fat, and therefore will make anyone who ingests it high in fat, too. Right? Maybe not.

Two new studies seem to point to just the opposite. Several middle-aged men who participated in a Swedish study and consumed high-fat dairy products, were tracked over a 12 year period and showed much less propensity of becoming obese when compared to men who followed a low or no high-fat diet in the same study. The research appeared in the journal Scandinavian Journal of Primary Health Care.

In the second study involving the meta-analysis of 16 empirical studies showed that - despite working under the hypothesis that a diet of high-fat foods leads to higher heart disease risk and contributes to obesity - no evidence supporting the claim was found. Actually, according to the study which appeared in the European Journal of Nutrition, consumption of high-fat dairy products were instead associated with a lower obesity risk.

Non-fat and low-fat yogurts still command a larger portion of the market but on the organic side of the things products with higher saturated fat content is, surprisingly, on the upswing. It's unclear why that is. A previous study involving children also showed that a low-fat diet was more likely to lead to obesity.

"There may be bio-active substances in the milk fat that may be altering our metabolism in a way that helps us utilize the fat and burn it for energy, rather than storing it in our bodies," said Greg Miller, of the National Dairy Council.

Besides the newly associated weight benefits, whole organic milk also contains higher levels of omega-3 fatty acids which help reduce the risk of cardiovascular diseases. It's also speculated that consumption of higher fat content may lead to a greater and faster feeling of being satisfied and full, and lead to a sooner cessation of the urge to eat.

For purely scientific reasons I'll be heading for the refrigerator in a moment to see if that's the case.

SOURCE
NPR story

Jan
03
2014

Aging in reverse gracefully: Scientists are successfully changing old lab mice into young ones.
Aging in reverse gracefully: Scientists are successfully changing old lab mice into young ones.Courtesy Andreas-photography
Bob Dylan first sang about it in the chorus of his 1964 song "My Back Pages" when he wrote ""Ah, but I was so much older then/I'm younger than that now"." He reinforced the notion ten years later when he released "Forever Young" in 1974.

It's all about staying young and not growing old - not ageism mind you - but anti-aging.

In a study appearing in a recent issue of the journal Cell, researchers have successfully reversed the aging process by turning a 2 year-old into one that resembles one that's a mere 6 months old. In human terms this would be equivalent to turning a 60 year-old back into a 20 year-old.

Dr. David Sinclair, professor of genetics at Harvard Medical School, and his team of researchers injected aging mice for a week with a compound known as nicotinamide adenine dinucleotide (NAD+), a natural chemical made from young cells. As mammalian cells age, NAD+ production drops by half causing mitochondrial dysfunction, and the processing of oxygen to fall off. Cells then become vulnerable to the various ailments that aging attracts. But in the treated older mice the cells began to take on the vitality and appearance of young mice.

Sinclair will next try administering NAD+via the drinking water used by lab mice to see how things go . If it has the same effect on the mice's cells, someone call Ponce de Leon because we could be talking about an actual Fountain of Youth!

Since NAD+ is a naturally produced compound, the concern for harmful after-effects is slight. Human trials could begin as early as next year - but it's not going to be cheap - somewhere in the neighborhood of $50,000 a day!

If I win the lottery in the next few months, I'll be first in line to become 20 years-old again, but only if I can retain my experience and any wisdom I may have acquired along the way. But if not, I guess I'll just start humming Dylan's "Knocking on Heaven's Door."

Time magazine story
Guardian story
BBC Health News

Dec
28
2013

Restoration of Haplocanthosaurus: a Late Jurassic sauropod whose remains are found in Colorado, Utah, and Wyoming.
Restoration of Haplocanthosaurus: a Late Jurassic sauropod whose remains are found in Colorado, Utah, and Wyoming.Courtesy FunkMonk via Wikimedia Commons
The partial remains of a somewhat rare sauropod dinosaur have been discovered in Old Snowmass, near Aspen, Colorado. Paleontologist John Foster of the Museum of Western Colorado in Grand Junction said that fossils of a Haplocanthosaurus were found by college student Mike Gordon in 2005 on land owned by his mom and stepfather. If you remember, Snowmass was the site near Aspen where a large collection of mammoths, mastodons, and other Ice Age mammals were uncovered back in 2010. This latest discovery is about six miles from the other site but in a much, much older rock layer. Foster said the Lower Morrison Formation, from where Haplocanthosaurus remains were collected dates back to the Late Jurassic, about 155-152 million years ago.

It's a very exciting find because few specimens of Haplocanthosaurus exist. The first were also found in Colorado, in Garden Park near Canon City, by Carnegie Museum of Natural History paleontologists William H. Utterback and John Bell Hatcher in 1901. The type specimens (H. priscus and H. utterbacki) were described by Hatcher in 1903. The fossils were prepared under the direction of chief preparator, Arthur S. Coggeshall.

Mounted skeleton of Haplocanthosaurus delfsi: Cleveland Museum of Natural History
Mounted skeleton of Haplocanthosaurus delfsi: Cleveland Museum of Natural HistoryCourtesy ScottRobertAnselmo via Wikimedia Commons
Compared to its larger and heavier long-necked, small-headed cousins such as Apatosaurus and Diplodocus, the Haplocanthosaurus was a relatively small-sized sauropod dinosaur with a length of 35 to 40 feet and weighing maybe 14 tons. While most sauropods have hollow spaces in their backbones, a distinguishing characteristic of Haplocanthosaurus is the solidness of its vertebrae which Foster confirmed by doing a scan of the fossil bones at a local hospital in Grand Junction.

Haplocanthosaurus hindlimb: Science Museum of Minnesota
Haplocanthosaurus hindlimb: Science Museum of MinnesotaCourtesy Mark Ryan
The only mounted specimen of Haplocanthosaurus is the referred species (H. delphsi) on exhibit at the Cleveland Museum of Natural History in Ohio. No skull of the sauropod has ever been found so the head is just a fabricated guess. Other post-cranial remains exist, including some here at the Science Museum of Minnesota that were collected in Wyoming, but in general fossils of the dinosaur are rare. Material from only 10 individuals are known.

So far the Old Snowmass site has provided some vertebrae, ribs and a pelvis. but the landowners have been very accommodating in allowing the museum access to the dig site, and Foster hopes to find more Haplocanthosaurus bones - maybe even some skull material - in the coming summer season.

SOURCES and LINKS
Aspen Times story
More Haplocanthosaurus info
Osteology of Haplocanthosaurus by John Bell Hatcher
Jurrassic West: The Dinosaurs of the Morrison Formation and Their World by John Foster