One way to understand how the ecosystem of the Antarctic originated is to look at its very base: tiny organisms called dinoflagellates, the little creatures that attract bigger creatures, and thus in effect support all of life in the ocean. Dinoflagellates produce hard cysts that fossilize well, and researcher Sander Houben and his team recently published findings in Science indicating that, once Antarctic ice began to spread over what was formerly a lushly forested, warm sub-tropical continent, the makeup of the ocean’s dinoflagellate population dramatically changed.

The Antarctic ice sheet began spreading to inland Antarctica about 34 million years ago, during a climactic shift caused by a decrease in atmospheric carbon dioxide that was cooling the planet, known as the Eocone-Oglicene extinction event.  The Antarctic ice sheet is one of two polar ice caps on Earth, and covers 98% of the Antarctic continent, making it the largest single ice mass on Earth. Put another way, that’s 61% of all fresh water on Earth, held in the ice cap.

Within a period of 200,000 years (a small slice of time from planet Earth’s perspective), glaciers formed and spread over the continent of Antarctica. The types of animals and plants able to survive on Earth was shifting greatly at this time, as the changing climate caused a worldwide mass extinction event. Antarctica was no different—the spreading ice meant that that photosynthetic dinoflagellates  disappeared, as there’s little light to be found in the frigid conditions under sea ice. Only the predatory dinoflagellates, which feed on other types of algae, survived. Because of the seasonal ebb and flow of ice coverage, a pattern that still exists in Antarctica, algae grow in short bursts in spring and summer, in plankton blooms, which attract dinoflagellates and krill to feed on them.

This direct linkage between the ice-sheet expansion and the types of critters that can survive there is a novel component to Houben’s paper. And the effects likely rippled up the food chain: Houben speculated, in discussion with New Scientist, that the shift to seasonal krill blooms may have driven the evolution of baleen whales. Baleen whales are thought to have appeared as early as the late Eocene period, between 39 and 29 million years ago. Scientists have discovered fossils from that period of whales with both tooth and baleen, an intermediary whale between toothed and filter-feeding whales. Perhaps the proliferation of tiny, nutrient-rich krill led to the pacification of a previously sharp-toothed predator to the baleen-bearing whales we recognize today.

Brinicles, first captured forming on film by the BBC in 2011, are hollow tubes of ice that descend from Antarctic sea ice. They look a lot like icicles, but aren’t. As sea water freezes into ice, it excludes salt and other ions, which get trapped in brine-rich compartments in sea ice. Brine has a lower freezing temperature than water, so if the sea ice cracks, the liquid is released, and immediately freezes any seawater that it comes in contact with, creating a hollow tube of ice descending into the water.

Julyan Cartwright and Bruno Escribano, authors of a recent study about brinicles, qualify the formations as “chemical gardens,” plant-like tubular structures that form when metal salt crystals are immersed in certain solutions. Chemical gardens are a common intro to chemistry experiment, and are ubiquitous in children’s chemistry kits, the “grow your own crystals” exercise. They are frequently seen around hydrothermal vents, growing upward.

By their very nature, brinicles (and chemical gardens) possess three key ingredients necessary for life: they create chemical gradients; they have the kind of electric potentials that may help jump-start life, and the brine-rich compartments they originate in have primitive membranes that contain fats, lipids, and and chemical compounds. These are the same conditions established by chemical gardens at hydrothermal vents, which are presently one of the top candidates for where life originated on Earth.

Thus one of the more important implications of the current study is that it proposes that brinicles could have been the site of a cold emergence of life, just as hydrothermal vents could be originators in the hot origins theories. Cold origins have been hypothesized by some scientists because some complex organic molecules form more readily in cold temperatures than in warm ones, and the surface of ice is a good substrate for these reactions.

Even if brinicles aren’t the spot where Earth’s life began, they may help in our ongoing search for habitable zones beyond our planet. Structures similar to brinicles could exist elsewhere in the solar system, for instance on Jupiter’s moons Ganymede or Callisto, where they could harbor life even in freezing conditions.

Animals were the pioneers for manned space flight. Scientists wanted to make sure animals could survive before they sent any humans. Russia sent dogs, rabbits, and mice on short duration flights in the early 1960s.

 The last Bion expedition was in 1997, when a fifteen day expedition took Rhesus monkeys, geckos, and amphibians into space. In its half-century of existence the Bion program has sent everything from seedlings, unicellular organisms, and plants to Rhesus monkeys, insects, rats, and fish into space.

Describing the animals that are picked to take part, Pavel Soldatov of the Institute of Biomedical Problems in Russia says, “They go through selection stages no less stringent than the astronauts.” One can’t help but wonder how an animal indicates its interest in being considered—do Mongolian gerbils dream of becoming astronauts someday? The animals selected must be social animals, Soldatov says, used to living with others. Three animals (of the same species) are assigned to each cage, where they are fed a paste-like, vitamin enriched cereal and water diet six times a day over the course of the journey.

The venture isn’t solely a Russian one. NASA is partnering with Roscosmos, Russia’s Federal Space Agency, and an international team of scientists to understand the effects of spaceflight down to the cellular and molecular level. NASA has appointed nine US scientists to work on collaborative research projects with Russian scientists relating to this mission, taking a whole-organism look at the animals.

The researchers are interested in how microgravity and radiation affect sperm motility in mice, a continuation of the omnipresent scientific obsession about whether humans will be able to procreate on decades-long expeditions in space.

Other experiments focus on how microgravity affects arteries, whether the spinal column changes, whether salivary glands and tendons are impacted, and whether the reduced biomechanical forces in microgravity lead to cartilage breakdown in major joints. Scientists will study the gravity-detecting mechanisms of the inner ear, and look for the potential development of motor disorders in space based on mice behavior.

Mounted on the exterior of the spacecraft are containers that will open in orbit to explore whether peptides and nucleotides get synthesized in open space, and the effects of the vacuum of space on plant seeds.

Upon return, the animals will be studied for their adjustment back to gravity, but will then receive the sad fate of euthanization so the scientists can more closely study the physical impacts of their journey.

Albert, First Monkey in Space image based on a photograph by NASA.

First: the Antarctic icefish, whose native habitat is 3,200 feet deep in the waters off the coast of Antarctica. Earlier this month, Tokyo Sea Life Park debuted its display of the only captive icefish in the world, prompting a flurry of news pieces about the fishes’ mysterious clear blood. The aquarium boasts they now have a mating pair of icefish, which could enable studies on their unique cardiovascular system in a controlled environment.

What makes the icefish so remarkable is that it defies yet another one of those rules of biology that seem to always have exceptions. In this case, it’s the rule that all vertebrates were thought to have red blood. This is because of hemoglobin, an iron-containing oxygen transport protein in the red blood cells of vertebrates. It carries oxygen from respiration organs like lungs or gills to all the tissues of the body, where it releases the oxygen to help power the tissues of the organism. Hemoglobin also collects the carbon dioxide produced from the activity of tissues and carries it back to the respiratory organs to be exhaled, and expelled from the body as waste.

The ocellated icefish was found, back in 2006, to have gin-clear blood. Importantly, this loss has not, thus far, been found to be of adaptive value, meaning that it costs the fish a lot more energy to circulate their blood in the absence of hemoglobin. The icefish has an unusually large heart, which scientists believe might be able to move oxygen around their body via blood plasma (the liquid component of blood). Their tissues might also be more densely laced with blood vessels than those of other fish, which could counter the lack of hemoglobin to some extent.

Last week a team of researchers including Dr. Theresa Grove of Valdosta State University, Dr. Kristin O’Brien of the University of Alaska, Fairbanks, and Dr. Lisa Crockett from Ohio University set out on an NSF-funded expedition to Antarctica to study the biology of Antarctic fishes. This group of “academic siblings” all earned their PhDs under the tutelage of Dr Bruce D Sidell, a leader in the field of fish adaptations to cold water at the University of Maine.

Perhaps the advantages that the species’ clear blood confers will be revealed from these new research efforts. Curiously, icefish also lack scales—and one theory is that, because cold water is more oxygen-rich than warm water, a lack of scales might mean the fish can absorb oxygen through their skin.

Clear Your Head—Literally

Another kind of transparent tissue has been in the news—this one not discovered in nature but created in the lab.

Researchers at Stanford University debuted their new technique to turn the entire organ of the brain transparent last week, creating quite a stir in the fields of neuroanatomy and “connectomics.”

The technique heralds a new age of researchers being able to view the brain at all tiers—from large networks of neurons to structures embedded deep in the brain—with ease.

What has normally stymied researchers in efforts to look inside brains is the presence of lipids, fatty cells that block the passage of light and are impenetrable by chemicals. The other lipid snag is that they’re structural: they help form cell membranes. When lipids are removed, typically, tissues fall apart. A see-through brain that’s a pile of jelly isn’t much good for research.

CLARITY, the work of Karl Deisseroth and his team, can “transform biological tissue into a new state”, says first author Kwanghun Chun, rendering it “intact, transparent, and permeable to macromolecules.”

This is a study that’s an important methodological advancement for how we do science. Basically, it uses a hydrogel to petrify the brain from within. An intact postmortem brain is immersed in the hydrogel solution, and a kind of small molecule called a monomer, infuses the tissue. The brain is then heated to about body temperature, and the monomers join into a polymer mesh that holds everything in the brain together, but doesn’t bind lipids—like a hydrogel hairnet for the brain. The researchers then quickly remove the lipids, revealing a see-through, preserved brain.

This hydrogel-brain hybrid creation is stiffer and more stable than untreated tissue. It can be employed to turn delicate and rare disease specimens into reusable resources, which could function as a sort of lending library of brains. Equally importantly, scientists can use the technique for reusable molecular studies on brains. Researchers can dye groups of cells and neurons fluorescent that they’re interested in for one study, and then wash the hydrogel-brain out and dye a different group for study.

The hope is that the ability to see the entire brain landscape—from bird’s eye to microscopic angles—could help scientists understand how changes to the brain cause disease.

A video from Nature on see-through brains:

Studying satellite images taken at the Keck Observatory in Hawaii, James O’Donoghue, a postgraduate researcher at the University of Leicester, and his colleagues noticed several mysterious dark bands on the surface of Saturn. They found that the bands correlate directly to magnetic lines that link the planet with her densest, wateriest, and most brilliant, rings, and shared these cosmic findings in a letter to Nature last week. The drizzle coming from her rings effectively douses the glowing hydrogen molecules we see on Saturn’s surface.

Saturn is famous, among humans, for her very photographic rings. But their origins, and evolution, have remained a mystery. How exactly were the rings formed to begin with? Are the rings we see today remnants of a previously more massive ring system? These recent observations  indicate than an electromagnetic erosion force pulls charged water molecules from the rings and deposits them in Saturn’s upper atmosphere, called an ionosphere. Perhaps this process is playing a part in shaping the rings over time.

The rings, which look like marvelous elliptical beams of light as seen in satellite images, are actually bands of collisional, self-gravitating water-ice sludge rocks, some of which are submicrometer-sized, and others the size of mini-moonlets a few kilometers across. All these watery ice objects behave like a dense gas together, orbiting Saturn in a thin disk.Saturn behaves like a big magnet, with magnetic field lines that link her rings to her body. Remember that iron-filing experiment in school? It’s like that.  The ionosphere of Saturn’s rings is “seen” by the magnet that is Saturn, says  O’Donoghue, “and effectively bounces back and forth from ring-to-planet. Some of these bouncing water particles go too far and never come back.”

There’s not much danger of the moonlets in the rings going anywhere, but the small particles in the orbiting disks behave differently when they acquire a significant electrical charge. When the sun charges the water molecules, they become vulnerable to getting swept down towards the planet’s upper atmosphere along the magnetic field lines.

The researchers estimate that about 30-40% of Saturn’s upper atmosphere is flooded regularly, the equivalent of between 1 and 10 Olympic-sized swimming pools a day. It may be, then, that these magnetic field lines are responsible for shaping the spacing and composition of the rings.

Thanks to James O’Donoghue for kindly answering my questions and consulting on images.

A fun video about how Earth’s magnetic field interacts with the Sun’s to create aurorae:

They might not seem like the most expressive eyes you’ve ever seen—but the beady eyes of extinct trilobites have a lot to say. Recently, they’ve given us some new insights into the evolution of vision.

Trilobites are one of the first animals in the fossil record to develop complex eyes (as opposed to the light-sensitive spots that passed as early eyes). So understanding trilobite vision is also understanding the origins of eyes themselves. It has even been hypothesized that trilobite vision drove rapid changes in their prey’s body structure as prey evolved to escape sighted predators, thus fueling the Cambrian Explosion.

Trilobites had compound eyes, akin to those of today’s insects and crustaceans. We know that because trilobites’ lenses were made of calcite, so they often fossilized along with the rest of the trilobite’s exoskeleton.

But underneath the lenses were sensory cells, which wired vision up to the brain. Those sensory cells, like other soft tissue, rarely fossilize. Thus, seeing how trilobites’ eyes were wired into their brains has been impossible up to now.

But a fluke of fossil preservation, along with some state-of-the-art technology, has now allowed scientists to see inside the trilobite eye. It turns out, bacteria that settled on the trilobite’s remains set down a thin layer of minerals on the surface of the eye, researchers reported last month in Scientific Reports. This trace shell persisted even after the cells themselves decomposed.

Using one of the most high-powered X-ray machines in the world, researchers were able to see these fossil remains at a cellular level, and map the trilobite’s entire visual system for the first time.

The findings indicate that trilobites had apposition eyes. Apposition eyes are the most common form of eye, and are likely the ancestral form of the compound eye. Many of today’s insects have both appositional eyes (more advanced, compound eyes) and ocelli (simple eyes that mainly sense light). But some arthropods, like spiders, make their entire eye out of ocelli.

That makes the closest living analogue of trilobite eyes the eyes of the horseshoe crab Limulus. Limulus is generally regarded as a “living fossil,” and thus may have retained this ancient visual system. Fine-scale studies of other trilobites’ eyes may help us map the critters’ evolutionary tree and better understand where and when the first eye developed, and how they led to the wide range of eye types we see in animals today. Something to think about next time you gaze deeply into the eyes of a horseshoe crab.

Illustration by Zina Deretsky
Image courtesy Chuck Wagner / Shutterstock

The size of small office buildings, the Saturn V moon rockets are the most powerful rockets ever to have flown. When tested, their engines shattered the windows of nearby houses. To date, the Saturn Vs are the only launch vehicles to have transported human beings beyond the low Earth orbit.

There are “stages,” types of engines of varying power, attached to rockets that help launch them into space. When the Saturn V moon rockets blasted off Cape Canaveral between 1967 and 1973, they flew east over the Atlantic Ocean. The Saturn rockets were made up of three stages, and when the first had used up all its fuel, about 2.5 minutes into the flight, it was jettisoned and chucked into the ocean, re-entering orbit at 5,000 miles an hour and impacting the ocean surface at a damaging pace, so as not to crash land and harm any humans.

The crew, which Bezos refers to as the A-Team, included recovery experts, underwater archaeologists, sonar experts, remote operated vehicle (ROV) technicians, and Irish diver Rory Golden, who found the main ship’s wheel of the Titanic back in 2000. The team used NASA’s flight records to estimate where the engines would have fallen into the sea as a starting point for their search. ROVs were deployed after sonar had targeted the precise locations of the engines, traveling 4,000m down to get a glimpse of the engines at rest.

Using ROVs to explore the deep sea is not that unlike going to space, Bezos remarked in his blog post. Images of gray horizon lines and seemingly lifeless empty space looked strangely similar to the images that came back from the NASA moon missions. Both deep sea and space exploration seemed impossible until very recently, and have required almost unimaginable feats of engineering.

What Bezos’s team has pulled up from the depths is not actually entire engines; right now it’s more like engine parts that, when restored, might contribute to two complete examples of these engines. Entire intact engines are difficult to come by, because of the whole crash-landing process. Bezos’s initial goal of finding the engines from Apollo 11 might be tricky, as it’s difficult to read the serial numbers on the rockets from the scrapes and nicks they’ve endured in their travels.

Bezos writes that he hopes to restore the engines, which are still NASA property, such that they tell the story of our aspirations for space, and the most advanced technology of a recently bygone era, and also maintain the marks left by re-entry and their time at the bottom of the sea. And that’s the most compelling part of the story: Expeditions to space were the epitome of a now retro modernity. Perhaps what’s truly modern today is pulling the mangled remnants of space missions out of their watery graves with the next wave of cutting-edge technology.

It’s an ecosystem based on chemosynthesis, not photosynthesis, which is the process of producing energy in the absence of light—as well as, sometimes, the absence of oxygen. This dark biosphere is the first major ecosystem on Earth based on chemosynthesis.

Scientists sampled in 2004 near the Juan de Fuca Ridge, off the coast of Washington, which is a spreading center where hot lava wells out of the Earth and creates new basalt rock. Seawater circulates through 3.5-million-year-old crust.

Lots of different bacteria were present in the crust but the team focused on methane-producing and sulfur-reducing species. These microbes get their sustenance from inorganic molecules created during the chemical reaction between water and rock. DNA evidence indicates these are modern organisms, not fossils.

Professor Lever, careful to prevent contamination during sampling, raised the bacteria in a lab at UNC for five years after the sampling. The lab-raised bacteria released methane, another bit of evidence for an active crustal community. Thus, he concludes, even the deeper, buried parts of the Earth’s crust are home to living creatures.

It’s important to note that not all parts of the ocean crust have this community. But in the areas that do, these bacteria converting carbon to biomass might be providing a massive carbon sink impacting the global carbon cycle. They also might influence the water cycle, since 4 percent of the ocean’s water is circulated through basalt rock. Professor Lever thinks basaltic crust is likely one of the earliest hospitable environments on the Earth to support life.

This research could also shed light on the habitability of other planets, such as Mars, which have no oxygen. Rocks on Mars are iron rich, so there could be similar geochemical reactions to the ones seen in Earth’s crust.

A new study on plant reproduction finds that developing cells are very affected by altered states of gravity—a finding that has implications for our hopes for a future human society in space.

In order for plants to have sex, a pollen grain first lands on a stigma (the female part of a flowering plant.) Following a chemical come-hither signal from the stigma, the pollen grain grows a pollen tube, a tunnel for sperm cells to travel down to reach the egg for fertilization. Pollen tubes are the fastest growing cells in the plant kingdom. The pollen tube was used as a model system for a recent study on the effects of altered gravity on plant reproduction because a response in the pollen tube takes a matter of mere seconds.

Plants have the ability to sense gravity. There are specialized parts of some cells called statoliths, which occur, for instance, in plant root cells, which need to know which direction to travel—in this case, down into the ground. The cell senses gravity, and changes its behavior accordingly.

Pollen tubes don’t have statoliths and they don’t sense gravity. A pollen tube is on a mission to find and germinate an egg; if it were primarily concerned with responding gravity, that mission would be thwarted. The pollen tube grows in the direction of the egg, and it takes its cues from the egg’s chemical signals. This means that any impact of gravity on a pollen tube is due to the actual effects of gravitational force on weight-bearing loads in nature.

Much research has been done on the root-growing prospects of plants in space. But researchers wanted to understand the effect that altered states of gravity would have on a plant cell that doesn’t have statoliths. They exposed pollen tubes to two states of gravity: the first was 20 times the gravity of earth, the second, a stimulation of the lack of gravity in space.

What they found is that plants in microgravity grew smaller pollen tubes: their diameters were 8 percent smaller than those grown at Earth gravity. At five times Earth’s gravity, the tubes were 8 percent wider, and at 20 times Earth’s gravity, they were 38 percent wider.

This is because the assembly of cell walls was disrupted in microgravity, leading to a reduced growth rate. As a result, the germination rates were much lower in the lesser-gravity states, the researchers reported in PLoS ONE.

The findings are important for all kinds of reproduction in space. Cells’ internal transport is important in humans as well, particularly in the development of long neurons. If neurons can’t form properly, will we be able to grow babies of our kind with working brains in space one day? If plants can’t properly reproduce in altered gravity, will we be able to pull off agriculture in space?

A plant’s sap is responsible for transporting sugars from the site of their manufacture (the leaves) to growth centers (further up the branch or trunk of the plant). And the system has to strike a delicate balance: if the sap has a low concentration of sugars, there isn’t much energy flowing to the plant; if, on the other hand, there are lots of sugars in the sap it becomes too thick to pump efficiently. It’s a situation a lot like transporting any payload through a traffic artery, be that a paved highway or a canal with kayakers. So what’s in a plant’s best interest?

Researchers reviewed 41 species of plants and found that, though most plants have sugar concentrations of 18 to 21 percent, the optimal sugar concentration is a bit higher: 23.5 percent. That’s pretty sweet—twice as sweet as a Coke, for instance (10 percent sugar). At the other end of the spectrum, maple syrup—a distillation of the watery maple sap—is quite viscous with a sugar concentration of 65 percent.

Interestingly, though plants have generally evolved towards the optimum, a number of unusually sweet plants exist. This group consists primarily of crop plants such as corn (40 percent sugar) and potato (50 percent sugar), the sugar junkies of the natural world.  These extreme concentrations may be an artifact of selective breeding.

Image by Zina Deretsky