Findings From Tangle-Web Spiders Support Group Evolution | Simons Foundation

A study of spider colonies supports a controversial idea in evolution — that natural selection can act on communities as well as on individuals.

Alex Wild

Social spiders work together to capture a grasshopper.

As a rule, spiders are antisocial. They hunt alone, zealously defend their webs from other spiders, and sometimes even eat their mates. “Cannibalism and territoriality comes naturally to Arachnida, even during sex,” said Jonathan Pruitt, a behavioral ecologist at the University of Pittsburgh. But a handful of the more than 40,000 known arachnid species on the planet have learned to rein in that aggression. Like ants or bees, they cooperate for the good of the group.

For example, so-called tangle-web spiders form bands of 1,000 or more to spin webs that stretch for hundreds of yards, entrapping flies, small birds and “virtually any invertebrate imaginable,” Pruitt said. Smaller groups of a few dozen work together “like a pride of lions,” he said; some of the spiders hunt for prey, while others rear the colony’s young.

The spiders present a puzzle to evolutionary biologists. According to ordinary Darwinian natural selection, only the fittest individuals will pass on their genes. But if that’s the case, why do tangle-web spiders act in ways that might conflict with an individual’s drive to outcompete its neighbors? A spider that defends the nest might put itself at personal risk, jeopardizing its chances of producing offspring. And a spider that rears the young might have to wait to eat until the hunters are sated, so it might go hungry. These are not behaviors that would be expected to enhance an individual’s fitness.

Biologists have long argued over the question of how natural selection can promote the evolution of traits that are good for the group, but not necessarily for the individual. Scientists have developed a number of mathematical models to attempt to explain the phenomenon. According to one model, known as kin selection, highly related organisms such as bees and ants can develop altruistic behavior — for example, many females forgo reproduction in order to raise the queen’s brood — because they will still pass down their genes indirectly, through the queen.

But despite its altruistic appearance, kin selection is selfish — it helps an individual’s genes to survive. Can natural selection promote truly unselfish traits, behaviors that are good for the group, but not necessarily to the benefit of individuals (or their immediate kin)? Some evolutionary models predict that it can, but while these models have been successfully tested in the lab, they have been studied only indirectly in nature.

Now, however, a new study of Anelosimus studiosus, a species of tangle-web spiders, published this week in Nature, suggests that evolution does indeed work at the level of the group. If certain groups of animals are more productive than others — that is, if they produce more progeny — then evolution will tend to favor the traits that make such fecundity possible. According to Pruitt, the findings are the first to provide direct evidence that natural selection can drive the evolution of a group trait in the wild.

Social Spiders

Female tangle-web spiders possess two basic personalities: aggressive “warriors” and docile “nannies.” The warriors spend their time capturing prey and defending the group from predators and parasites, while nannies raise the colony’s young. (To figure out an individual’s personality, scientists put it in a box with other spiders — aggressive arachnids fight for space while docile ones cuddle, Pruitt said.)

The Hen Gangs

USDA

The product of the most famous — and profitable — experiment in group selection gets served on millions of breakfast plates every day. Commercial chickens kept for egg production are typically housed in group pens, an efficient arrangement that also presents a problem for farmers: The most productive birds tend to be the most aggressive. They can lay lots of eggs because they terrorize and sometimes kill their cage mates, hogging all of the group’s food. If you breed chickens from individuals with a high egg-laying capacity, “you get hens that produce the most eggs or meat, but at the expense of their neighbors,” said Michael Wade, an evolutionary biologist at Indiana University in Bloomington.

In the 1980s, William Muir, an animal scientist at Purdue University in West Lafayette, Ind., came up with a better plan. Rather than selecting the best individual egg layers for breeding, he picked the groups that produced the most eggs. Egg output improved dramatically, because group selection produced kinder, gentler birds better suited to living in a group.

The peaceful chickens have become a classic example of group selection. But they are also the result of a distinctly human force. Biologists don’t yet understand how often natural environmental forces drive adaptation of the group. “That’s where the controversy is nowadays, not so much whether group selection can work but how often it produces a trait,” said Peter Nonacs, an evolutionary biologist at the University of California, Los Angeles. “Now we are transitioning from an argument among mathematical biologists to something experimentalists are trying to parse out.”

The balance of warriors and nannies in any particular Anelosimus studiosus colony appears to be tuned to fit the colony’s habitat. In large colonies with an ample food supply, warriors tend to abound, while colonies in sparser regions are dominated by nannies.

How does nature maintain this balance? One possibility is that it’s the result of evolution at the individual level. In this scenario, warriors might do better in prey-rich areas because there’s simply more prey for them to eat, while nurses might thrive in prey-poor areas because they may not require as much food as the warriors do.

However, there may be a different explanation. If the group, not the individual, is the most important basic evolutionary unit, then the group as a whole will evolve characteristics that are best suited to the environment, such as an intrinsic ratio of warriors to nannies. Colonies with the ratio best suited to the environment will be most likely to survive. Others will be more likely to die off.

To figure out which of these two possibilities is correct, Pruitt put together an array of custom-made spider colonies in the lab, creating different blends of personalities. He took spiders from warrior-heavy colonies and used them to assemble new groups that were heavy on the nannies. He also used spiders from mostly docile colonies to create warrior-laden groups. In addition, he assembled control groups that matched the composition of their original groups. He then transferred each colony to a tangle of chicken wire and transplanted the nests into various locations in Tennessee, where the spiders rapidly abandoned the wire to weave treetop webs. Some of the colonies were returned to their ancestral homes. Others went to new, foreign terrain.

After a year, 60 percent of the colonies were extinct. Control groups that returned to their ancestral homes tended to do well, and those that were transplanted into a new environment generally died. Neither of these outcomes was much of a surprise.

The most interesting results came from colonies made up of spiders that had been forced into a composition different from the one they grew up in — warrior-majority colonies containing spiders from mostly docile groups, for example. The colonies whose composition fit the new environment tended to survive. But over time, surviving colonies reverted to their members’ original group composition. The warrior-majority colonies went back to having more nannies, for example. On the face of it, this is bizarre behavior; if the colonies are well-suited to their environment, why not maintain that ratio? It seems that some innate sense, perhaps encoded in the spiders’ genes, pulled the colony back to its original configuration, even though this change meant the colony would perish.

Study suggests neurobiological basis of human-pet relationship

Credit: Noël Zia Lee, Wikimedia Commons

It has become common for people who have pets to refer to themselves as "pet parents," but how closely does the relationship between people and their non-human companions mirror the parent-child relationship? A small study from a group of Massachusetts General Hospital (MGH) researchers makes a contribution to answering this complex question by investigating differences in how important brain structures are activated when women view images of their children and of their own dogs. Their report is being published in the open-access journal PLOS ONE.

"Pets hold a special place in many people’s hearts and lives, and there is compelling evidence from clinical and laboratory studies that interacting with pets can be beneficial to the physical, social and emotional wellbeing of humans," says Lori Palley, DVM, of the MGH Center for Comparative Medicine, co-lead author of the report. "Several previous studies have found that levels of neurohormones like oxytocin – which is involved in pair-bonding and maternal attachment – rise after interaction with pets, and new brain imaging technologies are helping us begin to understand the neurobiological basis of the relationship, which is exciting."

In order to compare patterns of brain activation involved with the human-pet bond with those elicited by the maternal-child bond, the study enrolled a group of women with at least one child aged 2 to 10 years old and one pet dog that had been in the household for two years or longer. Participation consisted of two sessions, the first being a home visit during which participants completed several questionnaires, including ones regarding their relationships with both their child and pet dog. The participants’ dog and child were also photographed in each participants’ home.

The second session took place at the Athinoula A. Martinos Center for Biomedical Imaging at MGH, where functional magnetic resonance imaging (fMRI) – which indicates levels of activation in specific brain structures by detecting changes in blood flow and oxygen levels – was performed as participants lay in a scanner and viewed a series of photographs. The photos included images of each participant’s own child and own dog alternating with those of an unfamiliar child and dog belonging to another study participant. After the scanning session, each participant completed additional assessments, including an image recognition test to confirm she had paid close attention to photos presented during scanning, and rated several images from each category shown during the session on factors relating to pleasantness and excitement.

Of 16 women originally enrolled, complete information and MR data was available for 14 participants. The imaging studies revealed both similarities and differences in the way important brain regions reacted to images of a woman’s own child and own dog. Areas previously reported as important for functions such as emotion, reward, affiliation, visual processing and social interaction all showed increased activity when participants viewed either their own child or their own dog. A region known to be important to bond formation – the substantia nigra/ventral tegmental area (SNi/VTA) – was activated only in response to images of a participant’s own child. The fusiform gyrus, which is involved in facial recognition and other visual processing functions, actually showed greater response to own-dog images than own-child images.

"Although this is a small study that may not apply to other individuals, the results suggest there is a common brain network important for pair-bond formation and maintenance that is activated when mothers viewed images of either their child or their dog," says Luke Stoeckel, PhD, MGH Department of Psychiatry, co-lead author of the PLOS ONE report. "We also observed differences in activation of some regions that may reflect variance in the evolutionary course and function of these relationships. For example, like the SNi/VTA, the nucleus accumbens has been reported to have an important role in pair-bonding in both human and animal studies. But that region showed greater deactivation when mothers viewed their own-dog images instead of greater activation in response to own-child images, as one might expect. We think the greater response of the fusiform gyrus to images of participants’ dogs may reflect the increased reliance on visual than verbal cues in human-animal communications."

Co-author Randy Gollub, MD, PhD, of MGH Psychiatry adds, "Since fMRI is an indirect measure of neural activity and can only correlate brain activity with an individual’s experience, it will be interesting to see if future studies can directly test whether these patterns of brain activity are explained by the specific cognitive and emotional functions involved in human-animal relationships. Further, the similarities and differences in brain activity revealed by functional neuroimaging may help to generate hypotheses that eventually provide an explanation for the complexities underlying human-animal relationships."

The investigators note that further research is needed to replicate these findings in a larger sample and to see if they are seen in other populations – such as women without children, fathers and parents of adopted children – and in relationships with other animal species. Combining fMRI studies with additional behavioral and physiological measures could obtain evidence to support a direct relationship between the observed brain activity and the purported functions.

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2015 BMW i8 review: The first eco-friendly supercar | ExtremeTech

Meet the 21st century supercar: the BMW i8 plug-in hybrid. It’s insanely fast despite having three cylinders, not eight or twelve. On country roads you cruise in supreme comfort and quiet. The first 20 miles of your trip come from electric power.

The i8 employs electric motors front and back, the gas engine in back, two transmissions, and lithium-ion batteries running through the middle of the cockpit. The body is all-carbon fiber, the fibers coming from BMW’s own hydro-powered factory. The BMW i8 is a Chevrolet Volt on steroids. It is a sports cars with an environmental conscience. The i8 wins our Editors’ Choice award as the best of the new breed of supercars.

Driving the BMW i8: Yowza!

The toughest part about driving the BMW i8 is getting in: You have to climb over a door sill virtually even with the top of the seat cushion, while ducking under the low-slung scissor doors. To paraphrase mama, “Always wear good underwear. You never know when you’re going to the hospital, or getting out of an i8.” Once aboard, the cockpit is surprisingly roomy for a sports car other than the front-to-back tunnel that houses 217 pounds of lithium-ion batteries. It’s also very BMW-like: pushbutton start, a freestanding 8.8-inch LCD display atop the center stack, the eight programmable buttons that tune your favorite stations or call home, the beer tap-looking shifter, the Eco-Normal-Sport rocker switch, and of course iDrive.

Press the button and … nothing much happens once the instrument panel lights up. No V12 engine roaring to life a foot from your ears. That’s because the i8 starts each day as an electric car. But it moves off swiftly. After 20 miles on the 7.1 kWh battery, sooner if you tromp the throttle, you are in gasoline-and-electric mode and aboard a rocket ship. Zero to 60 mph happens in a shade over 4 seconds. Yes, there are old-fashion supercars with 0-60 times under 4.0 seconds, but they aren’t getting 75 MPGe and they’re paying a congestion surcharge to enter megacities. In London, there’s a weekday congestion charge of £11.50 ($18.75); EVs, PHEVs, and ultra-ultra-low emission vehicles are exempt.

Choose economy, performance, some of each

The i8 offers multiple driving modes, set by the shift lever and the Driver Experience Control, which is BMW-speak for a switch next to the shifter with “Comfort” and “EcoPro” rockers. If you do nothing other than pull the shifter straight back into Drive, the i8 is a front-drive EV with a range of 12-20 miles and a top speed of 75 mph. Push the shifter to the left and you toggle sportier driving modes.

Some plug-in hybrids such as the Chevrolet Volt won’t charge the battery while under way because it’s inefficient compared to recharging using electricity. BMW gives you that choice because in sport modes you need the electric motors to act as turbochargers. Even BMW can’t make a three-cylinder gasoline engine alone shove 3,300 pounds to highway speeds in 4-5 seconds. In performance modes, brake regeneration is turned way up and the car slows dramatically the moment you lift off the throttle, the same as when you’re karting, or aboard a riding lawn mower for that matter. If you hammer the throttle — tsk, tsk — and you’re in electric mode, the gas engine kicks in, but there’s a lag that feels like a second before all power sources are present and accounted for.

Electric front-drive, gasoline rear-drive, combined all-wheel-drive

The power sources are a 131 hp (96 kW) electric motor with a two-speed transmission driving the front, and a twin-turbo 1.5-liter gasoline engine 231 hp (170 kW) and six-speed automatic in back. There’s also a small electric motor in back that doubles as the starter motor. In full-on, pedal-floored driving, you get 362 hp or 266 kW. It’s possible to use only the front (electric), only the back (combustion plus electric), or front-and-rear powerplants combined. This is described as a through the road hybrid. With the 11 gallon tank of gas and full batteries, BMW estimates a range of 300 miles. That’s plenty far enough.

This is a car you could drive Seattle to LA, but there are better cars for going cross-country. Hardly any long-distance cars are the traditional supercar variety. For example, the $230,000 McLaren MP4-12C can be deafeningly loud unless you’re gentle on the throttle. The Mercedes-Benz McLaren SLR from the recent past was a blast to drive but the driver and passenger footwells became claustrophobic after an hour. The BMW i8 is refined yet retains enough performance to satisfy virtually all drivers.

The car itself, like the i3, is built around BMW’s “lifedrive” architecture: a super-strong body made of carbon fiber with replaceable plastic panels. The lithium-ion battery pack is in a tunnel in the middle of the car, safe from impact, helping provide a low center of gravity.

The i8 uses a recent form of carbon fiber without the characteristic hounds-tooth cross-weave. Except when you open the door of the i8, you don’t see much carbon fiber. You do in the i3 cockpit — and because it’s matte gray/black, you could equally call the look bland or industrial chic. Cooler perhaps is the rear window separating cockpit from engine compartment: It’s made of Gorilla Glass, same as on so many smartphones.

Flagship of the BMW i sub-brand

BMW created the i sub-brand and launched a carbon fiber fab in Washington State to showcase its designs for more sustainable transportation with an eye towards the world’s megacities, one where New York City barely tips the scales. Many have horrific pollution problems and gridlock. To enter some of these cities without paying a huge tariff, you need to do so under electric or zero-emissions power.

The BMW i3 is an urban runabout EV with room for four and a bit of luggage or groceries, like a Nissan Leaf

With a 230-volt charger, it takes less than two hours to reach 80% charge, three for full charge.

Plus BMW’s driver assists and carbon fiber luggage

The car comes standard with telematics, navigation, dynamic damper control (adjustable ride comfort), and a suite of apps falling under the umbrella of BMW Connected Drive to check on charge status or locate the car in a parking lot. Optional and highly recommended is the head-up display that provides speed, navigation, phone, and infotainment info at the base of your line of sight.

BMW Driving Assistant, a series of cameras and sensors that provide collision warning, pedestrian-and-obstacle detection and braking, surround and side views displayed on the center LCD, is available as an option.

A matched set of Louis Vuitton carbon fiber-fabric luggage is the most talked about option: large weekender bag, small weekender bag, and garment bag, all soft-side fabric; and hard-sided business case. They fit into the two smallish rear seats (Porsche 911 size) and the small rear trunk. It’s $20,000 for the set.

Should you buy if you have $150,000 to spend?

There is no car quite like the BMW i8. The closest plug-in hybrid supercar is the Porsche 918, $845,000 vs. the i8’s $136,000 base price. The Bimmer will sell in the thousands each year while the Porsche is capped at less than 1000.

The BMW i8 is also the latest ego-boost car for the rich and famous. One of the first i8s was auctioned off at the Pebble Beach concourse over the summer. Famous chefs, Wall Streeters, and entertainers are early buyers. That’s chef Thomas Keller of French Laundry and Bouchon, below, taking delivery. So it’s a logical successor to the Tesla Model S to wow the neighbors, which in turn displaced the Chevrolet Volt. The Model S is huge inside and has the trunk space to go cross-country but not the energy reserves: 250 miles max on a great driving day. Tesla owners and now Tesla officials have made coast-to-coast runs, but the need to drive out of the way to find the one-hour supercharger stations only underscores that today it is a thousand-mile cruiser only for those who drink the KoolAid. In 10 years, it will be a different story.

The other competition is the Porsche, Maserati, Alfa-Romeo, and used Lamborghini exotic sports car market. Some will be quicker but you won’t win style points for energy conservation.

If you do shop for an i8, the base model nicely equipped has a price of $135,700 in the US. The trim lines sound inspired by 1980s basketball player World B. Free (nee Lloyd Bernard Free): i8 Mega World, i8 Giga World, i8 Tera World, and i8 Pure World. Content varies a bit by country. Mostly the varying trim lines give you LED headlamps, different headliners and dash trim – eucalyptus wood, anyone? — but they also offer larger wheels and tires. If performance matters, the base i8 has for a supercar somewhat skinny front tires to help improve economy.

BMW says the i8 in the US will eventually offer laser headlamps but they’ll be tuned back on output. What’s safe for Europe does yet meet approval of our safety regulators, some of whom still seem befuddled by what makes for a safe ignition switch.

With or without laser lighting, the ExtremeTech Editors’ Choice BMW i8 represents the wave of the future: cars that are safe, efficient, eye-catching, and fun to drive. Baked into the price of the i8 is some of the startup costs for the carbon fiber factory. As it was with safety features since the 1990s, the affluent benefit first on high-end cars, and eventually airbags, anti-lock brakes, and stability control ripple down to $14,000 econoboxes that get 40 mpg. The BMW i8 along with the more pedestrian BMW i3 are beacons to the future. Maybe even laser beacons.

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This air-breathing solar panel stores its own electricity, cutting the cost of solar power significantly | ExtremeTech

It’s a solar cell! No… it’s a rechargeable lithium-air battery! No… wait… it’s both: It’s the world’s first all-in-one solar battery!

The new device, developed by Ohio State University, is essentially an air-breathing lithium battery that recharges via a built-in solar cell. This is significant, because one of the biggest problems with wide-scale solar power deployment is that you also need huge banks of batteries to store electricity — to even out spikes in generation when it’s cloudy or dark – and not only are those batteries expensive, but a lot of electricity is lost simply by traveling from the solar panels to external storage. An integrated solution is both cheaper and more efficient — about 25% cheaper and 20% more efficient, according to the researchers.

Ohio State’s solar battery has an ingenious design. There are three electrodes: The standard lithium metal anode, an oxygen/air electrode in the middle, and a photoelectrode — a photovoltaic solar cell — on top. An electrolyte sandwich ensures that electrons can travel smoothly between each electrode. When the battery is charging, the solar cell is connected to the lithium electrode — on discharging, the lithium electrode is connected to the oxygen.

Solar battery design and electrochemistry

Read: IBM creates breathing, high-density, light-weight lithium-air battery

As such, there are two very distinct chemical reactions that occur inside the solar battery. When the battery discharges, the lithium reacts with the oxygen to create lithium peroxide (Li2O2) and electricity — in effect, it breathes in. When the battery recharges, the solar cell creates electrons (via the photovoltaic effect) that convert the lithium peroxide molecules back into lithium ions (Li+) and oxygen (O2) — i.e. the battery breathes back out. There’s an iodide “shuttle” in the electrolyte that helps ferry electrons between the electrodes. The solar cell itself is fairly simple and cheap dye-sensitized titanium dioxide panel, with iron oxide (rust) as the dye. Dye-sensitized solar cells (DSSCs) aren’t quite as efficient as silicon — they max out at around 15% at the moment — but they make up for it by being cheaper and much more rugged. (The picture at the top of the story is the titanium dioxide mesh.)

The battery — developed by Yiying Wu and friends at Ohio State — actually seems to be almost ready for production. The design is being patented. Wu says the design will be licensed to industrial partners, where it will help bring down the cost of solar power. “The state of the art is to use a solar panel to capture the light, and then use a cheap battery to store the energy,” Wu says. “We’ve integrated both functions into one device. Any time you can do that, you reduce cost” — in this case, according to Wu, by a massive 25%. [Research paper: doi:10.1038/ncomms6111 – "Integrating a redox-coupled dye-sensitized photoelectrode into a lithium–oxygen battery for photoassisted charging"]

Solar battery characteristics

The current design has pretty good characteristics: It produces plenty of power and energy, and the battery portion of the device has a lifetime comparable to existing rechargeable batteries. The research, which is funded by the US Department of Energy, will now look at enhancing the solar battery’s performance with new materials.

Read: California’s new solar power plant is actually a death ray that’s incinerating birds mid-flight

In practice, this solar battery could be a huge deal. In general, one of the biggest deal-breakers when it comes to mass adoption of renewable power generation is reliability: When the wind stops blowing or the sun goes behind a cloud, you need good ol’ fossil fuels (or nuclear if you’re lucky) to bridge the gap. Currently, the only real solution to this problem is pumping water back to the top of a hydroelectric dam (if there’s one nearby) — or using huge banks of batteries (so-called grid energy storage). Those banks of batteries aren’t cheap, and transferring and storing energy in them isn’t particularly efficient. Ohio State could be onto something big here.

Now read: The secret world of power generation, and the arrival of Earth-spanning super grids

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Sikorsky S-97 helicopter shoots for speed with unusual design – CNET

It’s not every day you see a helicopter that looks like this. But that unconventional rotor placement will help drive the S-97’s exceptional speed.

The Sikorsky S-97 Raider has an unusual configuration, with two coaxial main rotors on top and a pusher propeller in the rear. Sikorsky Aircraft

First came the superfast X2 helicopter. Now Sikorsky Aircraft has put that experimental technology into a more mature package, the S-97 Raider.

Sikorsky hopes that the sleek, speedy design of the S-97, unveiled Thursday, will win the favor of the US Army as a potential replacement for OH-58D Kiowa Warrior helicopter, an airframe whose history dates back to the Vietnam War era, and as an aerial platform for special operations units.

The S-97 will be much faster than conventional helicopters, with a cruising speed of up to 220 knots, or 253 mph, according to Sikorsky. The Kiowa, which has been the Army’s primary scout helicopter since the mid-1990s, by contrast has a cruising speed in the area of 120 mph.

It’s not an idle promise. In September 2010, Sikorsky’s similarly designed X2 technology demonstrator reached a speed of 250 knots (287 mph), a feat that the longtime rotorcraft maker at the time said "unofficially shattered the helicopter world speed record." That feat has since been eclipsed — by a slim margin — by the Eurocopter X3.

Those high speeds for the X2 and S-97 stem from a combination of next-generation technology, a streamlined fuselage and, most dramatically, a striking reconfiguration of the standard rotor setup for a helicopter — two stacked main rotors and a pusher propeller at the tail.

In late May, Sikorsky first turned on power to its S-97 prototype, which at the time was about halfway through assembly. Sikorsky Aircraft

It’s not an everyday look for a helicopter, to say the least.

The two main rotors of the S-97 are coaxial, and they rotate in opposite directions, driving both lift and forward flight. That counter-rotation has the benefit of balancing out the torque and evening the lift from the long and rigid spinning blades. The coaxial design is uncommon, but not unprecedented — it’s long been a distinguishing characteristic of helicopters from Russian manufacturer Kamov. It’s also a more complex beast than a traditional single-rotor configuration.

What’s even more unusual element is the pusher rotor at the rear. Where a standard helicopter uses a side-facing tail rotor to offset the torque of the main rotor in front, the pusher propeller of the S-97 will assist in high-speed acceleration and deceleration.

The S-97 prototypes, Sikorsky has said, will go beyond the X2 aircraft in several ways, demonstrating precision maneuvers in low flight speed, high G turning maneuvers at over 200 knots, and hot-day hover performance at altitudes up to 10,000 feet.

When all’s said and done, the privately funded S-97 program will cost Sikorsky and its partners $200 million (75 percent from Sikorsky itself) for the construction and testing of two prototypes, the first of which was on display Thursday.

"Sikorsky will begin ground testing shortly and is on track for first flight this year," Steve Engebretson, Sikorsky’s director of advanced military programs, said in an emailed statement. "The entire rest of the flight program will take about a year to complete."

The company plans to demonstrate the aircraft’s capabilities to the US military beginning in 2015.

In a separate project, Sikorsky is working with Boeing on an X2-based helicopter called the SB-1 Defiant in a precursor program to the the Army-led Future Vertical Lift initiative, which aims to find a next-generation medium-lift helicopter for use across all the military branches. The first flight for that program is expected in 2017.

With a composite airframe, the 36-foot-long single-engine S-97 prototype has a maximum gross weight of just over 11,000 pounds. (The X2 demonstrator had a gross weight of 6,000 pounds.) The cockpit will seat two pilots side-by-side, and the cabin behind them will fit six combat-equipped soldiers. The aircraft, which will feature fly-by-wire controls, will be able to carry a variety of external weapons and sensors to suit missions including light assault or armed aerial scout.

The US Army has not yet made any formal announcement about a long-term replacement for the Kiowa. Last month, the Army saw its final class of eight aviators complete Kiowa flight training at Fort Rucker, Alabama.

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How Did Modern Chickens Get So Damn Big? | First We Feast

From 1948 to the present, selective breeding made your dinner what it is today.

Written by Janaki Jitchotvisut | October 2, 2014 at 2:13 pm | 1 Comment

The three chickens you see above were raised on the exact same diet, for the same length of time, and under the same conditions. The left-hand chicken is a breed from 1957. The middle chicken is a breed from 1978. The right-hand one is a breed from 2005. (Photo: Poultry Science via Vox)

You may not know it, but the popularity of chicken in the U.S. is partially due to its being one of the few proteins not rationed here during World War II. But chickens of today are so different from the chickens that existed just 50 years ago, your great-grandparents might not even recognize them.

As you can see in the image above (courtesy of Poultry Science, with breed dates added by Vox), chickens have gotten a whole lot bigger over a relatively short period of time.

To understand how they got this way, it’s important to have a little context for that graphic.

A Brief History of U.S. Commercial Chickens

Photo: North Carolina State University Library

Back in 1948, the biggest supermarket chain in the U.S. was called A&P, or the Great Atlantic & Pacific Tea Company. The chain held a “Chicken of Tomorrow” contest, inviting farmers all over the country to participate. The purpose, according to Modern Farmer, was “development of superior meat-type chickens.”

The winning chicken would have more meat all around, but the most important thing was more white meat. The winning chicken should also grow faster. With these criteria in mind, farmers all over set about their work.

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