Stories tagged Life Science
Science FridayCourtesy Science Friday Today,
"Of the orchid genus catasetum, Charles Darwin wrote: "I never was more interested in any subject in all my life than in this of Orchids." The male flowers in this genus evolved an unusual pollination program. They propel a package of pollen onto the backs of visiting bees. The bees endure the blow (which would be like a 150-pound person getting hit with a few bowling balls) in exchange for orchid aromas that the bees use to attract mates.
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Those sassy whalesCourtesy Currier & IvesWord on the street is that sperm whales may have individual names. I hope so, frankly, because I'm sick of calling them ... that.
Sperm whales, it seems, have calls that are unique to the region they live in. So whales in the Caribbean might have a different call than whales living in the South Pacific. But there are parts of sperm whale calls that are, on the surface, the same in whales around the world.
I say, "on the surface" not as some ocean-related pun, but because there's a part of the whale's call—five clicks at the beginning of a call—that seem to be totally unique to individual whales. All whales make the five clicks, but if you analyze the sound in detail, there are actually subtle variations in the sounds that are unique to the whale making them. Because it comes at the beginning of each phrase, or "coda string," and because the variations are perceptible from every direction (some whale calls sound different depending on how the listener is oriented to the caller), some scientists think that the clicks could represent the "names" of individual whales, who are identifying themselves as they call out.
Pretty neat, huh?
PS—"Pretty neat," but not completely neat, because I probably can't distinguish between the whales' clicks. Here, then, is a short list of names for any whales interested in adopting more standard monikers:
-Herman
-Squid Blood
-Crybaby
-Fudgie
-Moby II
-Gentle Jeff
-Spermy
-Winston
There are, like, dozens of other possible names. These are just the first to come to mind.
Archaeopteryx: Thermopolis specimen.Courtesy Mark RyanThis year marks the 150th anniversary of the announced discovery of the first fossils of Archaeopteryx, a remarkable chimera of both bird and reptile traits. The first evidence identified was a single feather discovered at a limestone quarry in Solnhofen, Germany. This was in 1860. The German paleontologist Hermann von Meyer described the fossil in 1861, naming it Archaeopteryx lithographica. That same year, the first skeletal remains came to light, and although headless, the London specimen, as it became known, showed clearly both avian and reptilian characteristics.
The unique and iconic fossil appeared just two years after publication of Charles Darwin’s On the Origin of Species and helped bolster the naturalist’s theory of evolution through natural selection because its appeared to be a transitional fossil between reptile (dinosaur) and bird. Could Darwin have asked for any better evidence?
Since then nine other specimens have been found, including the Berlin specimen around 1877, which is considered one of most complete. For many years some Archaeopteryx specimens languished in collection drawers because they had been initially misidentified as another creature entirely. In 1970, Yale paleontologist John Ostrom was investigating a so-called pteradactyl fossil at a museum in the Netherlands, when he realized it had been misidentified and was actually an Archaeopteryx. The fossil had been found at Solhofen in 1855, five years prior to the feather! The museum curator was so shaken by Ostrom’s announcement, he clumsily wrapped the specimen in a paper bag and presented it to Ostrom so he could take it back to Yale for further study. Ostrom, by the way, re-ignited the “birds are dinosaurs” debate in the 1960s after his discovery of Deinonychus and his comparison of its structural features with those of birds.
The Thermopolis specimen, the latest Archaeopteryx fossil, became known around 2005 and was donated anonymously to the Wyoming Dinosaur Center in Thermopolis, Wyoming. I happened to visit the museum in June of 2007 during the first week the fossil went on public display, and was able to see the spectacular specimen firsthand. The small fossil (about 1.5 feet square) was displayed behind a small, glass opening in the wall. There was no crowd to speak of so I was able to take in and photograph the fossil for a long stretch of time by myself. Looking at it, your eye is immediately drawn to the distinct feather impressions evident on both its wings and tail. The head, arms, and legs are spread out across the slab, and even though it died 150 million years ago, it looks as flat and fresh as road kill on a modern highway.
About the size of a large crow, Archaeopteryx was an odd amalgam of both bird and reptile. It had slightly asymmetrical flight feathers, wings, and a furcula (wishbone) - all traits found in birds. But its pelvis, skull and sharp teeth were reptilian (although some skull features are bird-like), and it ha a long tail like a reptile. Its bones weren’t hollow, like the bones of modern birds are, nor is its sternum (breastbone) very pronounced; it’s flatter and without a large keel where, in birds, muscles flight are attached. And it also possesses gastralia (“belly ribs”), a feature found in reptiles and dinosaurs. The inner toe (the hallux) in the Thermopolis specimen doesn’t appear to be reversed so it couldn't grasp or perch and was probably more earth-bound than arboreal. Interestingly, its second toe was extensible – meaning it could be pulled back and elevated for tearing into flesh, just like the middle toes of such dinosaurs as Troodon and Velociraptor. Truth be told, if its feathers hadn’t been preserved, Archaeopteryx would have been classified a carnivorous bipedal dinosaur. In fact, one of the existing Archaeopteryx fossil was first identified as a Compsognathus until preparation revealed its feathers.
Solnhofen and much of Europe in the Late Jurassic: A cluster of islands off the coast of the North American continent.Courtesy Ron Blakey, NAU GeologySo what kind of environment did Archaeopteryx live in, and why are its fossils so well preserved? Well, during the Late Jurassic, southern Germany and much of the rest of Europe were pretty much a group of large islands poking out of the Tethys Sea off the coast of North America. What is today the Solnhofen quarry was then part of an island lagoon protected by a barrier reef. Geological evidence in the strata suggests the lagoon dried up several times followed by periods of re-flooding with seawater. Mixed into a brackish soup of coral debris and mud, and in a warm climate conducive to rapid evaporation, the lagoon’s bottom water levels became anoxic, that is depleted of oxygen. Low oxygen meant less bacterial activity and subsequently slow decomposition of any organism that happened to die or get swept into the stagnant lagoon. Burial in the carbonate muck was swift, leaving fresh carcasses no time to be pulled apart by currents or scavengers.
Solnhofen limestone has been used for centuries as a building stone. Because the rock’s matrix is so fine and splits so evenly (sediment deposition likely occurred in very calm waters), the material was later quarried to produce stones for lithography, a printing technique first developed in 1796, and the source of Archaeoperyx’s species designation. Many early scientific illustrations, including some of the first images ofArchaeopteryx were preserved as lithographs created using Solnhofen limestone.
Archaeopteryx commorative coin: Germany will issue the 10 Euro coin in the summer of 2011Courtesy Federal Republic of GermanySolnhofen’s fossil record shows that the lagoon’s biological population was diverse. Fish, turtles, lizards and insects, crocodiles, crustaceans, ammonites, squid and starfish, mollusks, pterosaurs, and even the soft remains of jellyfish are preserved in the fine-grained limestone. But the premiere creature is of course the Archaeopteryx, which remains the earliest bird (or most bird-like dinosaur, if you will) known to date. As research on existing specimens continues and new fossils appear it's exciting to imagine what advances will take place in the dinosaur-bird connection debate. Whatever happens, Archaeopteryx lithographica will remain one of the most significant and iconic fossils ever discovered. It's no wonder that later this year on August 11th, the Federal Republic of Germany will issue a 10 Euro silver coin to commemorate the 150th anniversary of the discovery of its most famous fossil.
SOURCES and LINKS
Witmer Lab Archaeopteryx blog
UCMP Archaeopteryx page
Solnhofen limestone of the Jurassic
Polyommatus blue butterflyCourtesy Rongem BoyoOne of my favorite 20th century writers is the Russian-born Vladimir Nabokov (1899-1977). Many people were (and many probably still are) shocked by the subject of his best-known novel, Lolita, which he wrote in English in the early 1950s. But Nabokov’s use of the language in that book - and others - is at times so exquisite and so finely-crafted, that it’s equally shocking to realize that English wasn’t his native tongue but rather his second language taught to him by his governess while he was growing up in St. Petersburg. He was also well versed in French, so language played an important role in his life, as his many novels, poems, and essays attest. But growing up to become one of the 20th century’s greatest writers was not something he planned, because at age seven he had discovered another passion: collecting butterflies.
Nabokov said in later interviews that had it not been for the 1917 Russian Revolution, he would have probably been a lepidopterist at some obscure museum in St. Petersburg. But fate brought him eventually to the United States where (before publication of Lolita made him independently wealthy) he made his living mainly by teaching literature at Wellesley College and Cornell University. He also volunteered at the American Museum of Natural History - where he learned to dissect butterflies - and at the Harvard Museum of Comparative Zoology.
During the summer months he liked to mix his passions as he explained in the afterword to later editions of Lolita:
Every summer my wife and I go butterfly hunting. The specimens are deposited at scientific institution, such as the Museum of Comparative Zoology at Harvard or the Cornell University collections. The locality labels pinned under these butterflies will be a boon to some twenty-first-century scholar with a taste for recondite biography. It was at such of our headquarters as Telluride, Colorado; Afton, Wyoming,; Portal, Arizona, and Ashland, Oregon that Lolita was energetically resumed or on cloudy days.
Around 1945 he came up with a new theory of migration for the Polyommatus blue butterflies. Without the use of genetics and by studying anatomical features (mostly genitalia), Nabokov speculated that Polyommatus blues found in South America evolved by migrating in five waves from Asia across the Bering Strait. At the time the prevailing migration theories involved land bridges across the Pacific, so no one gave Nabokov’s hypothesis much weight.
Professional lepidopterists weren’t that impressed with Nabokov. They admitted he was decent enough researcher and at describing specimens (his published descriptions numbered in the hundreds) but they didn’t think he offered much in the way new ideas.
But now it seems Nabokov has been vindicated. A new report in the journal Proceedings of the Royal Society of London has determined - through DNA analysis – that Polyommatus blues have indeed evolved through five separate migrations from Asia over the Bering Strait.
“It’s really quite a marvel,” said co-author Naomi Pierce of Harvard. Pierce was part of a team of lepidopterists from England and the United States that made several expeditions to Chile to study and collect specimens of Polyommatus blues, then returned to the lab for gene sequencing and computer analysis of the data. The results showed that the Polyommatus blues did indeed originate in Asia, and were more closely related to that 10 million year-old ancestor than they were to their South American neighbors. But they also revealed that the first wave arrived when the temperature along the Bering Strait was warmer. But that temperature was in decline, and subsequent migrations brought in hardier species of Polyommatus, better suited to colder temperatures that correlated with the temperature range existing around the Bering Strait at the time of each wave. The conclusions matched Nabokov’s hypothesis to a “t”.
“By God, he got every one right,” Dr. Pierce said. “I couldn’t get over it — I was blown away.”
Paleontologist Stephen J. Gould included an essay in one of his many books about Nabokov’s split loyalties between art and science (he termed it “intellectual promiscuity”) proposing if the writer had kept focused on just writing he might have created another Lolita. On the other hand, Gould mused, if Nabokov had only studied butterflies, he could have become a well-known (at least in some obscure circles) lepidopterist. If it sounds like the old adage “you can’t serve two masters”, Nabokov seems to have pulled it off equally well in both arenas. I think had it not been for his writing and the lifestyle it afforded him, he wouldn’t have had the luxury of pursuing lepidoptery as fervently and successfully as he did; and without his butterfly collecting, he never would have written his masterpiece. If you asked the seven year-old Vladimir what he wanted most to be remembered for, his answer wouldn’t have been “writing a great novel”. He had another aspiration in mind, which he fulfilled several years later during one of his summer breaks from teaching. While visiting the Grand Canyon with his wife, Nabokov discovered a new species of butterfly which he named Neonympha dorothea in honor of a family friend who was traveling with them. His satisfaction poured out a couple years later in a poem:
I found it and I named it, being versed
in taxonomic Latin; thus became
godfather to an insect and its first
describer – and I want no other fame.
- On Discovering a Butterfly (1943) by Vladimir Nabokov.
SOURCES
NYT story
Bioephemera article
Dragonfly wing: Its structure is aiding wind-power researchersCourtesy Mark RyanResearchers in Japan are studying the wing structure of dragonflies to help improve how micro wind turbines perform during high winds. Micro turbines are small, affordable energy converters that can be used in both urban and rural settings where giant turbines would be too expensive, too large, and too impractical. Micro turbines can be set up relatively easily in configurations of a single unit or as a bank of several units, and the energy generated can be stored in batteries.
They work on the same principle as the large turbines, but can generate power in wind speeds as low as 4 or 5 miles per hour. One fallback, though, is their generators can get overloaded when hit with high storm winds, producing more energy than the system can handle. Large turbines solve this problem by tilting their propellers - either by computer or otherwise - and adjusting their rotation speed. But that kind of technology just isn’t affordable with micro turbines.
That’s where studying dragonfly wings comes in. Aerospace engineer Akira Obata of Nippon Bunri University in Oita, Japan wondered how dragonflies were able to remain stable in flight at low speeds. He placed a plastic model of a dragonfly wing into a large tank of water laced with aluminum powder and videotaped the flow patterns. He noticed that as the water flow slowed down vortices arose on the wing’s surface that allowed the water to pass over the wing at the same speed, thus keeping it stable. But when water flow sped up the wings aerodynamics performance decreased.
So, Obata developed an inexpensive paper micro turbine with similar “dragonfly wing” bumps on its surface and it did just as he hoped. When air speeds flowing over the turbine wing increased between 15 and 90 mph, rather than speeding up its rotation and overwhelming its battery, the micro turbine curved into a conical shape that stunted rotation and kept power generation low.
New Scientist story
CNBC story on homemade micro turbine
Make your own micro turbine
PterodactylsCourtesy Mark RyanA recently discovered pterodactyl fossil is providing lots of new information about the flying reptiles. The 160 million year-old fossil slab contains the remains of an adult specimen known as Darwinopterus, and was brought to light by a farmer who discovered it in Jurassic-aged deposits in China. Pterodactyls - also known as pterosaurs – populated the skies of the Mesozoic Era and were contemporaries of their distant relatives, the dinosaurs. Remains of pterodactyls aren’t uncommon and have been found in many parts of the world. What makes this fossil so unusual and valuable is that it also contains an unhatched egg, evidence that strongly suggests the adult is a female. The research team, made up of scientists from Great Britain and China, nicknamed the specimen “Mrs. T”.
Extensive examination of the fossil revealed that the adult specimen has wide hips, but is without a crest on its head. This contrasts with other known specimens of pterodactyls that have both large crests and narrow hips.
"Mrs T shows two features that distinguish her from male individuals of Darwinopterus,” said David Unwin, a paleobiologist from the University of Leicester who was involved with the study. “She has relatively large hips, to accommodate the passage of eggs, but no head crest. Males, on the other hand, have relatively small hips and a well developed head crest. Presumably they used this crest to intimidate rivals, or to attract mates such as Mrs T.”
Bird eggs are relatively large and hard-shelled, but the Darwinopterus egg is small and appears to be soft-shelled, like that of a crocodile. Dinosaurs, crocodiles and pterosaurs split off from a common archosaur ancestor during the Permian age about 250 million years ago.
This all means paleontologists will be now able to separate male pterodactyls from female pterodactyls. Until this recent discovery many had been categorized as separate species. The study appears in the journal Science.
SOURCES
Science Daily story
NY Times story
Although, despite its elephant mother: it should be a true genetic mammoth, and not some sort of hybrid Altered Beast.Courtesy Tracy OY'all were probably walking around thinking, "Hey! There's pretty much no way a woolly mammoth could kill me. Dip-de-doo!"
And y'all were probably snuggling into bed each night, cozy in the knowledge that if there was any way a mammoth could end your life, it would have to be from a 12,000-year-old tusk falling off an overloaded tusk-shelf, or something. And you went to sleep happy and safe.
Well, y'all are about to feel like a jerk. Sorry, but 3... 2... 1...
Scientists in Japan want to clone a woolly mammoth and there's a chance, however imperceptibly small, that that cloned mammoth could kill you!!! Like, maybe you're having a birthday party in Japan, and, attracted by the smell of cake, the mammoth breaks free from its enclosure and stomps your whole party. And it eats your cake!
You're thinking a) mammoths don't give a crap about cake; and b) they've talked about cloning mammoths for years, and it still hasn't happened, and I haven't been attacked by any Pleistocene megafauna.
Ok. A) How do you presume to know if a mammoth will want cake or not? Plus, it doesn't have to be cake. Maybe you're just jogging through Japan, and the mammoth sees your mousy ears and decides you need a stomping. The scenarios are practically limitless.
And B) this particular announcement may be something new in the field of wild speculation. While previous plans to do some mammoth cloning have been dismissed on account of all available mammoth DNA being damaged by a dozen millennia, a new technique may have bypassed that hurdle. Scientists at Kobe's Riken Center for Developmental Biology have cloned a mouse from cells that had been frozen for 16 years, and they think the same method could be applied to frozen mammoth remains. If enough viable DNA can be obtained, it would be implanted in the egg of an African elephant to create a mammoth embryo.
This won't happen overnight, however. There's still research to be done, and clone success rates in normal animals hover around 30%. And even if a mammoth embryo is successfully created, elephant gestation lasts about a year and a half. If all goes well, the scientists think it's possible to have a living, cloned mammoth within 6 years.
So enjoy the next six years. After that... it could be a bloodbath!
The tooth be told: the government is recommending change in fluoridation levels in US water.Courtesy Miss TessmacherThe US government is recommending that fluoride levels in the country’s water supplies be lowered. The reason is because of a noted increase in fluorosis, a dark staining and streaking of teeth in some children caused by too high a level of fluoride.
Right now fluoride levels in US water range between 0.7 milligrams – 1.2 milligrams per liter, because communities differed in their needs. The Department of Health and Human Services and Environmental Protection Agency are now suggesting the level be set at 0.7 milligrams across the board. Several reasons are given for removing the range of levels established in the early 1960s. Fluoride is present in more products now, such as mouth washes, toothpaste, and supplements. Also, air-conditioning is far more prevalent in warmer climates today than it was when fluoridation first began, so the water intake of residents in living there has changed.
Fluoride was first added to US drinking water in the 1940s after it was noticed that some communities in the Southwest showed much lower cavity rates than the rest of the country. After investigating the anomaly, it was discovered that the water they were drinking was naturally high in the element fluoride.
According to Dr. Martin Spiller’s website the rise in tooth decay in early 20th century America was due to increased sugar intake. Interestingly, the rise correlates with the introduction and mass marketing of Coca-Cola (by Dr. John S. Pemberton) in 1886. I don’t know if there’s ever been an actual scientific study done on this connection but at any rate, you can read more about it on Spiller’s very enlightening (and somewhat troubling) Tooth Decay page. Some of the photos aren’t pretty.
Anyway, dental caries (i.e. tooth decay or cavities) became pandemic in America through the first half of the 20th century up until a couple decades after the Southwest-fluoride connection was discovered and the teeth of next generation of children were fluoridated. Since then water supplies (and our toothpastes) have been fluoridated to help prevent cavities. As you can imagine not everyone was enthusiastic about the government mandated program. Even today, if you type in the term “fluoridation” into Google or on YouTube you’ll find that controversy still surrounds the subject. Here’s just one. But in the end the good seems to far outweigh the bad.
Actually, I shudder to think what my teeth would have been like without fluoride. My sugar intake is probably too high and I’ve never gotten the hang of getting into a regular flossing routine. I’m learning, though. I just had a crown replaced last week with a new (and expensive) one because I had a cavity develop under the old one. When will I learn? Excuse me while I go floss.
SOURCE and LINKS
CNN story
More about fluoride
If it had hands: it would be holding your life in them. Just saying.Courtesy splorpGather ‘round, Buzzketeers, so that I might tell you all a story.
“What story,” you ask?
Is it the one about the little blond girl who is killed by bears for breaking and entering? No, not that story.
Is it the one about the boy who killed an acromegalic man by cutting down the tree that held his fort? No, it’s not that story either.
Could it be the story about the little Blood member who couldn’t tell the difference between a wolf and her own grandmother, and was subsequently devoured by that very wolf? Oh, I wish it were, but it’s not that story.
No, the story I have for you all is even more enduring and horrifying than all of those. It is the story of biodiversity, and how it will freaking destroy you if you mess with it.
Sure, snort dismissively if you must, but you’ll soon be singing a different tune. A sad tune about how everything you ever knew and loved has been taken away from you.
“But how can a concept—and a boring concept like “biodiversity”—hurt me?” Ah, see, but what you don’t know can hurt you. You’re like the little blond girl, screwing around in a house that belongs to bears. She might not have known that it was a bear house (although it’s hard to imagine that she could have missed all the signs), and yet she was destroyed. So listen up.
You see, all biodiversity is is the degree of variation of living things in an ecosystem. Lots of biodiversity in an ecosystem, lots of different things living there. Little biodiversity in an ecosystem, few species living there. And biodiversity includes all forms of life, from your vampire bats and hagfish, to your streptococcus and your slime molds.
At the moment, biodiversity on the planet is on its way down. Lots of the things we do these days make life harder for other species, until there are very few or none of them left. And, sure, no one wants to see a panda get hit by a train, or watch an eagle being run over by road grading equipment, but who cares about the smaller, grosser stuff, like algae or germy things? We could probably do with a few less of those, right? Right?
Wrong, Goldilocks! An attitude like that is bound to get you turned into bear meat.
And here’s where my story begins (again)…
Once upon a time, long, long ago, everything died.
Well, not everything-everything, but pretty well near everything. It was called “the Permian extinction” (we’ve talked about it on Buzz before: here), and more than 90% of all marine (water) species and 70% of all terrestrial (land) species on the planet went extinct. It was way worse than the extinction that would eventually kill off the dinosaurs, and it took the planet a lot longer to recover from the Permian extinction.
What caused the Permian extinction? Oh, you know, a lot of stuff. Probably a lot of stuff. See, while we can more or less say that the dinosaurs were killed off by a giant space rock, it’s harder to say what did in the creatures of the Permian period. After all, the Permian ended almost two hundred million years before the extinction of the dinosaurs. But people have plenty of good guesses: maybe a few smaller space rocks hit the planet, maybe massive volcanic eruptions in what would become Asia kicked dust and poisonous gas into the atmosphere, maybe the oceans suddenly released massive amounts of methane… probably it was a combination of these things and more, and the extinction probably happened in waves before the planet became a good place to live again.
But here’s another straw for that dead camel’s back: the algae died. Not all of it, but lots and lots of the algae died. But why, and why did it matter? After all, it’s just algae.
Scientists aren’t sure exactly what cause so much alga—microscopic plant-like ocean life that turns sunlight into food—to die, but it looks like a sudden rise in the levels of sulfur in the oceans might have had something to do with it. It could be that there was an explosion in the population of sulfur using, hydrogen-sulfide releasing bacteria in the oceans, which would poison the algae.
In any case, there was a large die off of the sort of species we don’t give a lot of thought to. And what happened? The bear meat hit the fan!
Because they turn so much sunlight into so much food, algae act as the basis for most marine food chains. When the algae were gone, photosynthetic bacteria took its place to some extent, but the bacteria were a poor substitute, and the oceans were left with much, much less food. Also, algae produce a significant amount of the planet’s oxygen, and their absence would have created atmospheric changes as well.
This alone might have been enough to cause extinctions, and combined with the other natural calamities of the end of the Permian, it’s no wonder there was such a massive extinction event.
What a good story, eh? Now, if someone asks you what’s so great about biodiversity among the slimier and more boring species, you can just repeat this post, word for word. Or you can repeat this, the short version, word for word: “Because, Mom, if the algae die, we’ll be left choking and crying among the ruins of humanity for the rest of our short lives. And happy birthday.”
The shores of the alien world: Mono Lake, California, Earth.Courtesy EeekBig news from NASA today, y'all.
NASA scientists are holding a conference at 2:00 EST today, and I hate to spoil the surprise, but word on the street is that they've discovered life on the planet Earth. Ah... but it's not what you think—word is that they've discovered life that's really different from everything else here.
Last year, I posted about the theory that this sort of thing might exist, but it wasn't until now that it has actually been discovered. Here's the gist: bacteria living in the mud of weirdo Mono Lake have been found to use arsenic as a building block of their bodies. That may not sound like much, but, if it's true, it would mean that these bacteria are different than every other living thing on this planet. Everything else that lives on this planet is made of carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. These creatures use arsenic instead of phosphorous.
Aside from being super cool and different, the discovery suggests that if life can exist in ways we didn't think was possible, it can exist in places we didn't think life was possible. Like other planets and moons in our own solar system.
More details after the conference, hopefully.
