California condors can reproduce without mating

Friday, June 24th, 2022

California condors, a critically endangered species, can reproduce without mating, according to a study by conservation scientists at the San Diego Zoo Wildlife Alliance:

During a routine analysis of biological samples from the California condors in the zoo’s breeding programme, the scientists found that two condor chicks had hatched from unfertilized eggs.

[…]

Scientists confirmed that each condor chick was genetically related to its mother but neither bird was genetically related to a male.

The two birds represent the first two instances of asexual reproduction, or parthenogenesis, to be confirmed in the California condor species, the zoo said.

“This is a very rare discovery because it’s not well-known in birds in general. So it’s known in other species, in reptiles and in fish, but in birds it’s very rare, in particular in wild species,” Dr Steiner said.

Dr Steiner said the discovery was particularly surprising, because both female birds were continuously housed with fertile male partners and had already produced chicks while paired with a male.

Asexual reproduction has never before been confirmed in any avian species where the female bird had access to a mate.

[…]

Both chicks were underweight when they hatched, Dr Steiner said.

One was released into the wild and died at the age of two in 2003, while the other survived for eight years in captivity and died in 2017.

When fed plasmalogens, aged mice perform more like young mice

Wednesday, May 25th, 2022

Researchers from Xi’an Jiaotong-Liverpool University, Stanford University, Shanghai Jiao tong University, and the University of Chinese Academy of Sciences report that plasmologens (found in sea squirts) reverse some signs of aging — in mice:

The effects of the plasmalogen supplement on learning and memory were tested by training mice to use a Morris water maze — a pool of water that contains a platform that serves as a resting area. Generally, mice do not like to swim, so over five days of training, they remember where the platform is and swim directly to it as soon as they are in the pool. However, older mice take longer to find the platform after the same amount of training.

Astonishingly, when fed with plasmalogens, aged mice perform more like young mice, finding the platform much quicker than the control group of aged mice that have not been given the supplement.

To find the reason for the improvement shown by plasmalogen-fed mice, the researchers took a closer look at changes happening within the brain. They found that mice that were fed the plasmalogen supplement had a higher number and quality of synapses—the connections between neurons—than the aged mice not given the supplements.

Why horses explode if you look at them funny

Wednesday, December 29th, 2021

“Why are cows so damn indestructible,” someone asks, “while horses keel over and die if mercury is in retrograde or a dog barked in Kazakhstan?” Gallus Rostromegalus explains — with a fair bit of strong language — Why Horses Explode If You Look At Them Funny, As Explained To Me By My Aunt That Raises Horses After Her Third Glass Of Wine:

When a horse runs at full gallop, it sort of… stops actively breathing, letting the slosh of it’s guts move its lungs, which is tremendously calorically efficient and means their breathing doesn’t fall out of sync. But it also means that the abdominal lining of a horse is weirdly flexible in ways that lead to way more hernias and intestinal tangling than other ungulates. It also has a relatively weak diaphragm for something it’s size, so ANY kind of respiratory infection is a Major Fucking Problem because the horse has weak lungs.

When a Horse runs Real Fucking Fast, it also develops a bit of a fluid dynamics problem- most mammals have the blood going out of their heart real fast and coming back from the far reaches of the toes much slower and it’s structure reflects that. But since there is Only The One Toe, horse blood comes flying back up the veins toward the heart way the fuck faster than veins are meant to handle, which means horses had to evolve special veins that constrict to slow the Blood Down, which you will recognize as a Major Cardiovascular Disease in most mammals. This Poorly-regulated blood speed problems means horses are prone to heart problems, burst veins, embolisms, and hemophilia. Also they have apparently a billion blood types and I’m not sure how that’s related but I am sure that’s another Hot Mess they have to deal with.

ALSO, the Blood-Going-Too-Fast issue and being Just Huge Motherfuckers means horses have trouble distributing oxygen properly, and have compensated by creating fucked up bones that replicate the way birds store air in thier bones but much, much shittier. So if a horse breaks it’s leg, not only is it suffering a Major Structural Issue (also also- breaking a toe is much more serious when that toe is YOUR WHOLE DAMN FOOT AND HALF YOUR LEG), it’s also having a hemorrhage and might be sort of suffocating a little.

ALSO ALSO, the fast that horses had to deal with Extremely Fast Predators for most of their evolution means that they are now afflicted with evolutionarily-adaptive Anxiety, which is not great for their already barely-functioning hearts, and makes them, frankly, fucking mental. Part of the reason horses are so aggro is that if denied the opportunity to ZOOM, it’s options left are “Kill everyone and Then Yourself” or “The same but skip step one and Just Fucking Die”.

When Hans G. Schantz shared this, I immediately thought of Ferdinand Porsche’s point about cars, rather than horses: “The perfect racing car crosses the finish line first and subsequently falls into its component parts.”

The travelling whale that reached the Pacific

Monday, July 26th, 2021

An ancient four-legged whale with hooves has been discovered:

The giant 42.6m-year-old fossil, discovered in marine sediments along the coast of Peru, appears to have been adapted for a semi-aquatic lifestyle. Its hoofed feet and the shape of its legs suggest it would have been capable of bearing the weight of its bulky four metre long body and walking on land. Other anatomical features, including a powerful tail and webbed feet similar to an otter suggest it was also a strong swimmer.

[…]

Previously, far older whale ancestors dating to about 53m years ago have been discovered in India and Pakistan. Until now scientists have disputed when and how whales first dispersed to the Americas and beyond.

The Peruvian fossil suggests the first whales would have crossed the South Atlantic, helped by westward surface currents and the fact that, at the time, the distance between the two continents was half what it is today.

The last few tail vertebrae are missing and so it is not clear if the creature’s tail would have featured the large paddle, known as a fluke, that allows some modern whales to power themselves along at speeds of more than 30mph (48 km/h). But it must have been an accomplished swimmer to have survived for days or even weeks at sea.

The fossil was excavated in 2011 by an international team, including members from Peru, France, Italy, the Netherlands, and Belgium. It has since been named Peregocetus pacificus, meaning “the travelling whale that reached the Pacific”.

The world’s first successfully cloned Black-footed ferret has been born

Friday, February 19th, 2021

The world’s first successfully cloned Black-footed ferret has been born, marking the first time a U.S. endangered species has been cloned:

“Elizabeth Ann” was born on December 10, 2020, and is the clone of “Willa,” a wild-caught Black-footed ferret whose cell line was cryopreserved in 1988. A genomic study led, funded, and developed by Revive & Restore in 2014 helped determine that Willa’s genome possessed nearly three times more genetic diversity than the current Black-footed ferret population. This means that her clone Elizabeth Ann is now the most genetically valuable Black-footed ferret alive. This birth is the result of a long-standing genetic rescue effort for the Black-footed ferret species, the goal of which is to increase the genetic diversity and fitness of one of America’s most endangered species to help ensure its full recovery in the wild.

Mighty Mice in Space

Friday, September 18th, 2020

A research team led by Dr. Se-Jin Lee of the Jackson Laboratory in Connecticut sent 40 young female black mice to the International Space Station in December, to study muscle loss:

In a paper published in the Proceedings of the National Academy of Sciences, Lee said the 24 regular untreated mice lost considerable muscle and bone mass in weightlessness as expected — up to 18%. But the eight genetically engineered “mighty mice” launched with double the muscle maintained their bulk. Their muscles appeared to be comparable to similar “mighty mice” that stayed behind at NASA’s Kennedy Space Center.

The PNAS abstract explains:

Among the physiological consequences of extended spaceflight are loss of skeletal muscle and bone mass. One signaling pathway that plays an important role in maintaining muscle and bone homeostasis is that regulated by the secreted signaling proteins, myostatin (MSTN) and activin A.

Here, we used both genetic and pharmacological approaches to investigate the effect of targeting MSTN/activin A signaling in mice that were sent to the International Space Station.

Wild type mice lost significant muscle and bone mass during the 33 d spent in microgravity. Muscle weights of Mstn -/- mice, which are about twice those of wild type mice, were largely maintained during spaceflight.

Systemic inhibition of MSTN/activin A signaling using a soluble form of the activin type IIB receptor (ACVR2B), which can bind each of these ligands, led to dramatic increases in both muscle and bone mass, with effects being comparable in ground and flight mice.

It’s not just mice who have muscle-building myostatin-related mutations, but Belgian Blue cattle, Flex Wheeler, a German toddler, a Michigan toddler, and “bully” whippets.

Wild bison to return to UK for first time in 6,000 years

Monday, August 3rd, 2020

Wild bison to return to UK for first time in 6,000 years , with the release of a small herd in Kent planned for spring 2022:

The £1m project to reintroduce the animals will help secure the future of an endangered species. But they will also naturally regenerate a former pine wood plantation by killing off trees. This creates a healthy mix of woodland, scrub and glades, boosting insect, bird and plant life.

During the initial release, one male and three females will be set free. Natural breeding will increase the size of the herd, with one calf per year the norm for each female. The bison will come from the Netherlands or Poland, where releases have been successful and safe.

[...]

Bison kill selected trees by eating their bark or rubbing against them to remove their thick winter fur. This creates a feast of dead wood for insects, which provide food for birds. Tree felling also creates sunny clearings where native plants can thrive. The trust expects nightingales and turtle doves to be among the beneficiaries of the bison’s “ecosystem engineering”.

The steppe bison is thought to have roamed the UK until about 6,000 years ago, when hunting and changes in habitat led to its global extinction. The European bison that will be released in Kent is a descendant of this species and its closest living relative.

The European bison is the continent’s largest land mammal and bulls can weigh as much as a tonne.

Rodents rely on restaurants for food

Sunday, May 24th, 2020

The Centers for Disease Control and Prevention (CDC) is warning that rodents are becoming increasingly aggressive as they scavenge for food:

In an advisory posted to its website, the health agency noted that rodents rely on food and waste generated at commercial establishments such as restaurants. Closures and limits on service have caused rodents to search for new sources of food and to exhibit more erratic behavior.

They have been forced to watch in frustration as the insects devoured their farms and gardens

Friday, May 1st, 2020

This has been quite a year. Now Africa is expecting a record wave of locusts:

First came the floods. The waters swamped bean and corn fields and created a breeding ground for a swarm of desert locusts the size of Manhattan that fanned out and destroyed a swath of farmland across eight East African nations as large as Oklahoma earlier this year.

Now their offspring are threatening a historic infestation—a second wave of locusts, 20 times as large as the first, that the U.N. warns could chew their way through 2 million square miles of pastureland, farms and gardens, around half the size of Western Europe.

The swarms, which would be by far the largest on record, are expected to descend as the new coronavirus accelerates across East Africa, raising the prospect of a double-shock to some of the world’s poorest and most heavily-indebted economies.

[...]

Compounding the problem, Gen. Kavuma’s unit also spends much of its time on the lookout for people violating stay-at-home orders as Ugandan authorities attempt to halt the spread of the transmission of the coronavirus. Uganda’s lockdown is one of the world’s strictest. During the previous infestation, farmers banged drums, whistled and threw stones to protect their crops. But in recent days they have been forced to watch in frustration as the insects devoured their farms and gardens, trapped inside by fear of the virus and the security forces enforcing the lockdown.

Farmers are trapped inside?

Leave bats, in particular, the hell alone

Tuesday, March 24th, 2020

David Quammen’s 2012 book Spillover charts the ecology and spread of “zoonoses,” diseases transmitted between animals and humans, and makes these four points:

Prepare for the worst, while hoping for the best.

Zoonotic spillovers will keep coming, as long as we drag wild animals to us and split them open.

A tropical forest, with its vast diversity of visible creatures and microbes, is like a beautiful old barn: knock it over with a bulldozer and viruses will rise in the air like dust.

Leave bats, in particular, the hell alone.

Salamanders and other amphibians glow green when bathed in blue light

Thursday, March 5th, 2020

Salamanders and other amphibians glow green when bathed in blue light:

Amphibians fluoresce green to yellow in response to blue (440–460?nm) (Figs. 1 and 2) and ultra-violet excitation light (360–380?nm) (Supplementary Fig. 2), but the biofluorescent light emitted under blue excitation is more intense than when excited by ultra-violet light (Supplementary Fig. 2). Fluorescent green coloration in response to blue excitation light is strikingly widespread across the amphibian radiation (Figs. 1 and 2) and is the focus of this survey. Every amphibian species and life stage we examined, including aquatic larvae, is biofluorescent (Supplementary Table 1). Peak fluorescent emissions coming from these amphibians (Fig. 2) fall within the spectrum of green light (ca. 520–560?nm). The intensities of fluorescent light we recorded were variable among taxa (Figs. 1 and 2) and weakest for those that lacked bright or reflective pigments (i.e., yellows, oranges, whites).

Salamanders and other amphibians are aglow with biofluorescence 1

The bird’s fingers are important for steering

Sunday, January 19th, 2020

Birds change the shape of their wings far more than planes do, and David Lentink, a professor of mechanical engineering at Stanford University, and his team explored this while creating their PigeonBot:

The researchers used common pigeon cadavers to try to figure out the mechanics of how birds control the motion of their feathers during flight. Scientists had thought the feathers might be controlled by individual muscles. But they learned that some aspects of bird wing motion are simpler than they expected.

Lentink says that several doctoral students realized that simply by moving the birds’ “wrist” and “finger,” the feathers would fall into place. When the bird’s wrist and finger moves, “all the feathers move, too, and they do this automatically,” he said. “And that’s really cool.”

The findings are some of the first evidence that the bird’s fingers are important for steering. The team replicated the bird’s wing on the PigeonBot using 40 pigeon feathers, springs and rubber bands connected to a wrist and finger structure. When the wrist and finger move, all the feathers move, too.

The researchers used a wind tunnel to see how the feather-and-rubber band design worked under turbulent conditions. “Most aerospace engineers would say this is not going to work well, but it turned out to be incredibly robust,” Lentink says.

They also pinpointed something interesting about how the feathers work together that helps most birds fly in turbulent conditions. At certain moments during flight, such as when a bird is extending its wings, tiny hooks on the feathers lock together like Velcro.

“These tiny, microscopic micro-structures that are between feathers lock them together as soon as they separate too far apart, and a gap is about to form. And it’s really spectacular,” Lentink adds. “It requires an enormous force to separate them.”

These tiny hooks are so small that they’re hard to see even through a microscope. Then, when a bird tucks its wing back in, the feathers unlock automatically, like directional Velcro. Separating the locked feathers makes an audible sound for most birds. The team published this finding in a separate paper in the journal Science.

It’s worth noting that the PigeonBot doesn’t incorporate something you might associate with birds’ wings – flapping. The designers were focused on incorporating the more subtle wrist-and-finger motions of the wings, so the bot appears to be gliding through the air while it’s in flight.

I guess Dune‘s ornithopters might not be so fanciful after all, and we might see a better human-power ornithopter, too.

Dogs follow a strict code of conduct

Tuesday, January 14th, 2020

Canids (members of the dog family) follow a strict code of conduct when they play:

1. Ask first and communicate clearly. Many nonhumans announce that they want to play and not fight or mate. Canids punctuate play sequences using a bow to solicit play, crouching on their forelimbs while standing on their hind legs. Bows are used almost exclusively during play and are highly stereotyped — that is, they always look the same — so the message “Come play with me” or “I still want to play” is clear. Play bows are honest signals, a sign of trust.

Even when an individual follows a play bow with seemingly aggressive actions such as baring teeth, growling or biting, their companions demonstrate submission or avoidance only around 15% of the time, which suggests they trust the bow’s message that whatever follows is meant in fun. Trust in one another’s honest communication is vital for fair play and a smoothly functioning social group.

2. Mind your manners. Animals consider their play partners’ abilities and engage in self-handicapping and role reversing to create and maintain equal footing. For instance, a coyote might not bite their play partner as hard as they can, handicapping themselves to keep things fair. And a dominant pack member might perform a role reversal, rolling over on their back (a sign of submission that they would never offer during real aggression) to let their lower-status play partner take a turn at “winning.”

Human children also behave this way when they play, for instance, taking turns overpowering each other in a mock wrestling match. By keeping things fair in this manner, every member of the group can play with every other member, building bonds that keep the group cohesive and strong.

3. Admit when you are wrong. Even when everyone wants to keep things fair, play can sometimes get out of hand. When an animal misbehaves or accidentally hurts his play partner, they typically apologize, just like a human would. After an intense bite, a bow sends the message, “Sorry I bit you so hard — this is still play regardless of what I just did. Don’t leave; I’ll play fair.” For play to continue, the other individual must forgive the wrongdoing. And forgiveness is almost always offered; understanding and tolerance are abundant during play as well as in daily pack life.

4. Be honest. An apology, like an invitation to play, must be sincere. Individuals who continue to play unfairly or send dishonest signals often quickly find themselves ostracized. This has far greater consequences than simply reduced playtime. For example, my long-term field research shows that juvenile coyotes who do not play fair often end up leaving their pack and are up to four times more likely to die than those individuals who remain with others. There are substantial risks associated with dispersal by young coyotes, and violating social norms, established during play, is not good for perpetuating one’s genes.

[...]

A few people have asked me if dogs always play fair, mentioning a few examples in which play escalated into an encounter that seemed to be aggressive or it seemed like this was going to happen. I explain that this is extremely rare, and tell them about a study by Melissa Shyan and her colleagues in which it was reported that fewer than 0.5 percent of play fights in dogs developed into conflict, and only half of these were clearly aggressive encounters.

That place is like Africa Light

Monday, January 13th, 2020

Greg Ellifritz just got back from Africa, where not quite everything went to plan:

Before leaving the airport, I tried three different ATMs to get local currency. All three rejected my card. My ATM card wouldn’t work at all in South Africa. That’s the first country I’ve been to (besides Cuba) where my ATM card didn’t work. That made life challenging, but I was smart enough to bring an emergency stash of American cash that I was able to exchange in a dodgy black market currency transaction (arranged by a taxi driver) for some local South African Rand.

I can understand why some folks don’t like traveling.

He booked a room in a guest house on a farm outside of Jo-burg:

Outside, there was an eight foot cement wall topped with an additional four feet of electric fence surrounding the entire property. It’s was crazy to see that every rural house was a completely walled estate. The South Africans really like barbed wire and electric fences. Almost every house was enclosed by a wall with an electrified fence.

[...]

On my third day, I hired a private tour guide (recommended by the owner of my guesthouse) to give me a tour of some of the grittier parts of Jo-burg. That was an education just as potent as the Apartheid museum.

There are entire parts of the city classified as “no-go” zones. If you don’t live there, you are not welcome. There are constant protests, roadblocks and tires burning in the streets of some neighborhoods. The downtown area of Jo-burg is a wasteland. Most of the skyscrapers are empty as large corporations have fled to the safer suburbs. Many buildings have no utilities, but were nonetheless inhabited by squatters.

I’ve never seen so many homeless people in one place. There were thousands of homeless people squatting in dozens of buildings without any electricity or running water. People defecated openly by the side of the road. There were huge trash drum fires and lots of people aimlessly hanging out in the streets.

While driving through the downtown area, we had to keep changing routes due to large amounts of rubble placed in the roadway as a roadblock during recent protests. I’ve been a lot of places. Downtown Jo-burg looked more apocalyptic than any other location I’ve visited and gave me an idea of what things would look like if our power grid fails. It wasn’t a happy thought.

Following the tour of downtown, we drove into some of the “townships” or slum areas. The most famous Jo-berg township is SOWETO (South Western Township) where Nelson Mandela lived. The townships had lots of ramshackle buildings, but the people seemed much more organized than the squatters living downtown. People were poor, but worked, had families and a purpose for existence. The townships I visited didn’t seem dangerous at all. The townships were kind of like the favelas of Rio de Janeiro without all the open air drug sales.

Ellifritz is a cop, and he carefully notes how gun laws and law enforcement work in other countries:

My tour guide was a former soldier, a gun owner, and an avid shooter. He explained that residents of South Africa could own a handgun and two hunting rifles with the proper permits. He owned a Glock 17 that he bought for 7000 Rand (about $500 US). Concealed carry was theoretically possible, but my guide didn’t know anyone who actually had the necessary permits to carry legally.

The cops in Jo-berg wore external plate body armor and often carried long guns (R-4 or R-5 rifles that are South African Galil variants). I only saw two cops armed with handguns. Both carried Beretta 92s. One was carried in a cheap nylon IWB holster that placed the gun so deeply in the beltline, that the grip was barely visible. The other carried his Beretta in a 1990s vintage Uncle Mikes “twist draw” retention holster on a duty belt with a big can of pepper spray.

I didn’t see any support gear like handcuffs or batons carried by the local cops. That fact might be a useful fact for you travelers to notice. When the cops aren’t carrying handcuffs, they clearly expect criminals to either submit to arrest without incident or be shot. No half measures.

No thanks. I’m good. I prefer to stay far away from cops who don’t train and carry less lethal weapons.

After Kruger, they made their way to the Karongwe Wildlife Reserve:

The monkeys in camp were an absolute menace. A group of about 20 raided our camp and began grabbing people. As I was trying to clear them off a neighbor’s porch, they tried an ambush attack.

I actually had a Mexican standoff with a growling monkey as I had my OC spray ready to hose him down. He kept growling and advancing. As soon as I pointed the OC canister at him, he stopped, stared at me for a few seconds, and then walked away.

He righteously should have gotten some spicy treats, but I didn’t want to forever be known as the dude who pepper sprays monkeys. The vervet monkeys are such a problem in some parks, that the government employs people armed with paintball guns and slingshots to keep them away from tourists.

At Karongwe they were also able to take a hike in the bush:

Since all of the “Big Five” most dangerous African game animals live on the property, we had to be accompanied by a guide and a “gun bearer.”

The gun bearer walked up to our group. He had a beat-to-shit CZ .458 Win Mag bolt gun. There was absolutely no finish left on the barrel. The wood stock looked like some small varmint had chewed on it.

The rifle was unloaded. The bolt wasn’t in the gun. The gun bearer was carrying the bolt stuck behind this belt in the appendix position. He was wearing a leather loop cartridge holder full of 10 rifle rounds at the four o’clock position behind his hip.

I thought: “Wow, they are actually sending us out into the bush with our ‘protection’ carrying a disassembled and unloaded rifle. What could possibly go wrong?”

We walked about 100 meters away from the camp and the gun bearer installed the rifle bolt and loaded it with five rounds. He took the rounds from the most forward cartridge loops, thereby guaranteeing that he would have to reach far behind his back to access the remaining cartridges should he have to reload in a hurry. Brilliant.

The gun bearer made an elaborate show of loading each round into the magazine. He then pushed the cartridges down with his thumb and moved the bolt forward. Once the bolt was over the top of the cartridges in the magazine, he closed and locked the bolt with a flourish, stating “Now we are ready.”

I normally shut my mouth in the evidence of such stupidity, but I couldn’t hold back.

“There’s no round in the chamber. You aren’t ‘ready.’ The gun is in a better condition to fire now as compared to when you brought it out unloaded, but you are far from ‘ready’.“

He kind of looked at me sheepishly. I continued:

“Don’t worry. When the lion attacks you while you are trying to get the gun in play, I’ll be there. I know how to run that bolt. I’ll pick up your rifle off the ground, chamber a round and shoot the lion off your corpse.

It’s great having a plan. Now we’re ‘ready.’”

Neither he nor the guide really had too much to say after that.

Absolutely frightening muzzle discipline displayed during the whole hike. When the guide talked, the gun bearer stood with the rifle butt placed on his boot, leaning forward with both hands covering his muzzle. He was essentially using the muzzle of a loaded .458 Win Mag as a hand rest.

Then they went to Zimbabwe:

A passenger on the flight from South Africa to Zimbabwe said the following as we were disembarking and walking into the sweltering airport:

“We aren’t in South Africa anymore. That place is like ‘Africa Light.’ Now we are in the real deal.”

That’s a quality analysis.

It’s a very vulnerable point, and plants have targeted it

Wednesday, October 9th, 2019

Monarch butterflies eat only milkweed, a poisonous plant that should kill them, and even store the toxins in their own bodies as a defense against hungry birds:

Only three genetic mutations were necessary to turn the butterflies from vulnerable to resistant, the researchers reported in the journal Nature. They were able to introduce these mutations into fruit flies, and suddenly they were able to eat milkweed, too.

[...]

Insects began dining on plants over 400 million years ago, spurring the evolution of many botanical defenses, including harsh chemicals. Certain plants, including milkweed, make particularly nasty toxins known as cardiac glycosides.

The right dose can stop a beating heart or disrupt the nervous system. For thousands of years, African hunters have put these poisons on the tips of arrows. Agatha Christie wrote a murder mystery featuring foxglove, which produces cardiac glycosides.

The toxins gum up so-called sodium pumps, an essential component of all animal cells. “It’s a very vulnerable point, and plants have targeted it,” said Susanne Dobler, a molecular biologist at the University of Hamburg in Germany.

These pumps move positively charged sodium atoms out of cells, giving their interiors a negative charge. Heart cells need sodium pumps to build enough electrical charge to deliver a heartbeat. Nerves use the pumps to produce signals to the brain. If the pumps fail, then those functions come to a halt.

[...]

The researchers compared the genes that serve as blueprints for the sodium pump in poison-resistant species, like the milkweed beetle and the milkweed bug. Most of these species, it turned out, had gained the same three mutations.

[...]

Monarchs share one of the mutations with a related butterfly that doesn’t eat milkweed, and a second mutation with a closer relative that eats milkweed but doesn’t store cardiac glycosides in its wings. The third mutation arose in an even more recent ancestor.

Gaining these mutations gradually altered the sodium pumps in the monarchs’ cells, Dr. Dobler suspected, so that the cardiac glycosides couldn’t disrupt them. As the butterflies became more resistant, they were able to enjoy a new supply of food untouched by most other insects.

[...]

Noah Whiteman, an evolutionary biologist at the University of California, Berkeley, led the effort to test this hypothesis. “These three mutations may be the thing that unlocked the door” for the butterflies, he said.

He and his colleagues figured out how to use Crispr, the gene-editing technology, to introduce the mutations into fruit flies. The flies survive on rotting fruit, and even a small dose of cardiac glycosides can be deadly to them.

The researchers began by giving the flies the first mutation to arise in the ancestors of monarchs. The larvae that carried this mutation were able to survive on a diet of yeast laced with low levels of cardiac glycosides.

The second mutation let the flies withstand even more toxins, and the third made them entirely resistant. With all three mutations, the flies even ate dried milkweed powder.

The third mutation had another striking effect. When the flies with the gene developed into adults, their bodies carried low levels of cardiac glycoside, useful as a defense against predation.

O brave new world that has such insects in it!