Courtesy Bruce Marlin (via Wikipedia Creative Commons)Summer is heading our way and soon the familiar buzzing of cicadas will fill the air. But for some, particularly in the southern and eastern United States, the buzz will become a loud symphony of sound. That's because, this year, the Great Southern Brood will (actually already has in some places) reappear and millions of the insects will soon be crawling out of the ground to overwhelm us with their vast numbers and cacaphonic chorus.
Relax. Last weekend's rapture was a bust (or was it?), and there’s nothing to worry about in the biblical sense. It’s merely the latest appearance of Magicicada neotredecim and M. tredecim, two closely related species of cicada that show up every 13 years in the United States to fill the treetops with their buzzing song.
The most common genus of cicadas in the US is Tibicen and unlike Magicicada, cicadas in the genus Tibicen appear annually, not periodically. After a 2-3 year stint as nymphs, Tibecen cicadas emerge into their adult stage. The full-grown insect measures about 1-2 inches in length with long translucent wings and distinctive green, brown, and black markings on the middle of its body. Generations overlap so they show up every year and can be heard in many areas, including Minnesota, during the hot and steamy Dog Days of summer buzzing to high heaven. It’s that shrill, grating noise that builds in the air and sounds like someone is cutting up cement blocks with a chainsaw. As deafening as it can be, I like the sound, in much the same way I like the smell of rotting leaves in the fall, it triggers memories.
But I’m not sure how I’d feel about Tibicen's cyclical cousins - those belonging to the Magicada genus - that show up all at once in mass periodical emergences and put on huge choruses of buzzing. There are seven species that do this in the US, three in 13-year cycles, and four in 17-year cycles. Periodical cicadas are categorized into broods numbered in Roman numerals from I to XXX. The thirteen-year cycles occupy XVIII–XXX; seventeen-year cycles number I–XVII. Only about 15 broods are still recognized. There are still only seven cyclical species but some species emerge happen at different times in different regions, hence the number of broods. This year it will be a 13-year cycle called Brood XIX , and it is the largest of the 13-year cycles in terms of geography.
The numbers involved in a periodical swarm are huge but, as Vanderbilt biologist Patrick Abbot explains, the vast numbers increase the possibility of available mates and serve as a way to overwhelm the cicadas many predators, which include birds, snakes, turtles, spiders and wasps, and even fungi. It’s interesting that the periodical emergences have evolved into separate prime number cycles. The reason is probably to reduce competition between broods.
“Say you have two populations, one which emerges every five years and one which emerges every 10 years. Then they would emerge simultaneously every 10 years," Abbot said. "Whereas the period between simultaneous emergences between populations with 13- and 17-year cycles is 221 years."
Occasionally, two cyclical broods have been known to emerge simultaneously but usually the overlap is minimal. For example two 13-year broods rising at the same time but in adjacent regions.
During a brood’s synchronized emergence the number of individuals can be daunting. Some emergences have been estimated to contain something like 1.5 million cicadas per acre of land. That amounts to 800 tons (!) of biomass busily buzzing within a square mile of forest. Think of that!
But despite the huge numbers involved in a cyclical emergence, cicadas are pretty harmless, and don’t voraciously eat up crops like locusts do, nor do they sting or bite. The most damage done is by females when they make “v”-shaped slits in the bark of a twig to lay their eggs (I suppose this could feel like a sting if she mistakes your arm for a tree branch). But, come on, even this is nothing compared to a plague of locusts wiping out the summer corn crop.
The word cicada is Latin and means “buzzer” Very apropos, don’t you think? The males of the species spend a lot of time trying to get the attention of female cicadas by vibrating a membrane on their exoskeleton called tymbals. Each time the muscles contract or relax the tymbals they produce a click. Portions of the exoskeleton such as the abdomen or thorax help amplify the sound. The rapid vibration causes a shrill and (possibly annoying) buzzing, and each of the world’s estimated 2500-3000 species has its own distinct sound. The females, by comparison, make a rather boring click with their wings to attract males (I suppose the male cicadas don’t think it boring). You can replicate the female clicking by snapping your fingers in rapid succession a couple times.
When periodical cicada eggs hatch the nymphs drop down and burrow deep into the ground where they spend most of their lives sustaining themselves for several years ingesting fluids from tree roots and developing through five juvenile stages. Scientists suspect soil temperature triggers the emergence. When it reaches 64 degrees F., the nymphs head for the surface. It seems the likely catalyst since emergences in warmer, southern regions take place sooner than those farther north. Whatever the case, when they do emerge, the nymphs crawl up and attach themselves to nearby vegetation where they eventually molt out of their skins. They don’t begin adult activities until after their exoskeletons harden. So for the first 4 to 8 days after molting, they pass through a stage called teneral (meaning soft and tender) before the exoskeleton is complete. The adult stage of a cicada lasts anywhere from a couple weeks to a few months. Very short in comparison to their other life stages.
People eat cicadas in several areas of the world. And the females are meatier and more desired. I suppose the insect is a good source of protein but – there’s no way I’m ever doing that - I’d never eat one. Maybe I shouldn’t say “never”. Some Native American tribes supposedly survived times of famine by eating cicadas.
If you live in or are visiting an area that is or will soon be overrun by an invasion of the Great Southern Brood, rather than cowering in a corner and wailing and gnashing your teeth, head outside, go for a walk, and take in a symphony of cicada songs. While you’re out there enjoying the summer day, you can get even more involved by trying some of these neat cicada experiments. It will take your mind off the fact that you’re surrounded by 800 tons of buzzing biomass.
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Courtesy C-MOREHow would you like to be aboard a ship, circumnavigating the globe, collecting samples from the world’s ocean?
That’s exactly what Spanish oceanographers are doing on their Malaspina Expedition aboard the Research Vessel, R/V Hespérides. Scientists and crew left southern Spain in December, reached New Zealand in mid-April, and recently arrived in Hawai`i. The expedition's primary goals are to:
Courtesy C-MOREIn connection with the latter two goals, the Malaspina scientists met with their colleagues at the Center for Microbial Oceanography: Research and Education (C-MORE). The two groups of scientists are working together. "We can exchange data on the local effects, what's happening around the Hawaiian Islands, and they can tell us what's happening in the middle of the Pacific," said Dr. Dave Karl, University of Hawai`i oceanography professor and Director of C-MORE.
The Malaspina-C-MORE partnership is the kind of cooperation that can help solve environmental problems which stretch beyond an individual nation’s borders. The R/V Hespérides has now left Honolulu on its way to Panama and Colombia. From there, the scientists expect to complete their ocean sampling through the Atlantic Ocean and return to Spain by July. Buen viaje!
Courtesy NOAAWe often talk about the ocean ecosystem. And, indeed, there is really just one, world-wide ocean, since all oceans are connected. An Indian Ocean earthquake sends tsunami waves to distant coasts. Whitecaps look as white anywhere in the world. The ocean swirls in similar patterns.
However, oceanographers do find differences from place to place. For example, let’s take a closer look at the chemistry of two swirls, or gyres as they’re more properly called. Scientists have found a micro difference between the North Atlantic Gyre and the North Pacific Gyre. The Atlantic generally has really low levels of phosphorus, measurably lower than the North Pacific Gyre.
Courtesy modified from WikipediaPhosphorus is a very important element in living things. For example, it’s a necessary ingredient in ATP (adenosine tri-phosphate), the energy molecule used by all forms of life. Phosphorus is picked up from seawater by bacteria. All other marine life depends upon these bacteria, either directly or indirectly, for P. Therefore, if you’re bacteria living in the impoverished North Atlantic Gyre, you’d better be really good at getting phosphorus.
And they are!
Oceanographers at the Center for Microbial Oceanography: Research and Education (C-MORE) at the University of Hawai`i have made an important discovery. C-MORE scientists Sallie Chisholm, based at the Massachusetts Institute of Technology and her former graduate student Maureen Coleman, now a scientist at the California Institute of Technology, have been studying two species of oceanic bacteria. Prochlorococcus is an autotrophic bacterium that photosynthesizes its own food; Pelagibacter, is a heterotrophic bacterium that consumes food molecules made by others.
Courtesy C-MOREDrs. Chisholm and Coleman took samples of these two kinds of bacteria from both the Atlantic and Pacific Ocean. The Atlantic samples were collected by the Bermuda Atlantic Time-Series (BATS) program. The Pacific samples were collected in the North Pacific Gyre (about 90 miles north of Honolulu) by the Hawai`i Ocean Time-Series (HOT) program. The scientists discovered surprising differences in the genetic code of the bacteria between the two locations:
Drs. Chisholm and Coleman have discovered important micro differences between bacteria of the same species in two oceanic gyres. Now we can better understand how these microbes are working to recycle an important nutrient beneath the whitecaps.
Courtesy NASALife scientists study…well, life. They want to know everything about living things on planet Earth. One of the first things biologists want to know is who’s here. What kinds of plants and animals live in a forest? --or in a field? –or in the ocean?
If you’re an oceanographer who studies marine mammals, perhaps you’d go to sea on a ship with a good pair of binoculars and hunt for whales. As you focused your binoculars you’d be able to see different kinds of whale species. As you looked closer, for example at Humpback Whales, you'd see that each individual whale has a different black-white pattern on its tail. You might even take a biopsy, a small sample of whale flesh, and do a more detailed study of genetic differences among individual Humpbacks.
But what if you’re a microbial oceanographer? You sure can't use binocs to hunt for microbes! How can you study individual differences among tiny creatures that are only one-one-hundredth the width of a human hair? How do you hunt and capture single-celled bacteria, like Prochlorococcus, the most common bacterial species in the world’s ocean?
Courtesy C-MOREYoung scientists, Sebastien Rodrigue and Rex Malmstrom, at the Center for Microbial Oceanography: Research and Education (C-MORE) were doing research in Dr. Sallie Chisholm’s C-MORE lab at the Massachusetts Institute of Technology when they adapted a “laser-based micro-fluidic system” used commonly by medical researchers, for the study of marine bacteria. With this method they could put each individual tiny Prochlorococcus cell into its own little pool of seawater.
And then the excitement began.
Courtesy Dr. Anne Thompson, MITEven in scanning microscope photographs, each Prochlorococcus looks like just another teeny, tiny balloon; we can't see any individual differences. However, Sebastien and Rex used fast and inexpensive genetic methods and discovered an extraordinary variety of individual differences among Prochlorococcus. Of course the variety among these microbes doesn't have to do with tail patterns, like whales. Prochlorococcus vary in their method of getting nutrients, like iron, out of seawater.
So what? Why do we care?
We care A LOT because microbes like Prochlorococcus are operating at the nitty gritty level of cycling not only iron, but also other elements in the ocean. Like carbon. That's right, as in carbon dioxide accumulating in our atmosphere -- and ocean -- causing climate change and associated problems. The more we understand about individual differences among oceanic microbes, the more we'll understand how they influence and respond to changes in Earth's climate.
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.
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.
Courtesy 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.
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Courtesy 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.
Here's a story from the New York Times about a dog named Chaser that knows the names for more than a thousand items and even, according to her trainer, can perform more sophisticated linguistic feats such as understanding verbs and knowing that words might name a type of thing rather than an individual object.
Now, a dog that really, truly understood what you said to it would be a lot of fun to have around. (Of course, I'd probably have to curb my tendency to give dogs affectionate nicknames like Meathead and Stinky.) But even if critters like Chaser are "simply reading cues unconsciously given" by their trainers, isn't that a pretty amazing feat by itself? It seems to me that the ability to read little signals from humans, even ones that the humans aren't aware they're giving, isn't "simple" at all.
I once read a book by an animal scientist
Courtesy ~~Yuna~~that said that all animals are geniuses at the skills they use to survive. Maybe Chaser really is doing something similar to what human babies do as they learn to speak and understand language. But if she's not, I'd be willing to bet that whatever skill she's using is no less fascinating.
Courtesy 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.
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.”
Courtesy C-MOREThere are microbes…and then there are micro-microbes. Oceanographers on C-MORE’s BiG RAPA oceanographic expedition are finding bacteria the size of one-one-millionth of a meter in the oligotrophic (low nutrient), open-ocean of the Southeast Pacific, far from the productive waters off the coast of Chile. But that’s not all; some scientists are looking for the even smaller marine viruses in gallons of filtered seawater. Meet some of these micro-microbes in these video reports:
Courtesy Dr. Anne Thompson, MIT
Yes indeed, microbial oceanographers are taking home quite a collection from the South Pacific Ocean. In less than a week the good ship RV Melville will arrive at Rapa Nui (Easter Island), and scientists will step onto land for the first time in almost a month. They and their oceanographic samples will return to C-MORE laboratories around the U.S. The oceanographers are also returning with new hypotheses buzzing around in their heads. Now it’s time for them to take the next step in the Scientific Method: data analysis!