What if I told you that in Australia, a mouselike marsupial called antechinus breeds so manically during its three-week mating season that the males bleed internally and go blind until every male lies dead? And what if I told you that this isn’t the reason the species is facing an existential threat?
Reporting today in the journal Frontiers in Physiology, biologists from the University of New England in Australia and the Norwegian University of Science and Technology present troubling evidence that antechinus might be ill-prepared for a warmer world. The researchers set out to look at something called phenotypic plasticity in the yellow-footed antechinus, one of the creature’s 15 known species. Think of your phenotype as your body’s hardware, or physiology: your height and skin color and metabolism. This is in part coded by your genotype, the genetic software that powers the hardware. Phenotypic plasticity is the ability of a species to respond to environmental stressors—like temperature swings—by altering their physiology without mucking with all the underlying genetics.
For the antechinus, the researchers were interested in the plasticity of its metabolism. This is highly influenced by temperature: An adult antechinus’ metabolism shifts to expend less energy when it’s cold during the winter and there isn’t much insect prey for it to hunt. When it’s warm, an antechinus can afford to expend a lot of energy because the prey is plentiful.
The researchers, though, were more interested in how temperature affects antechinus babies—that is, how being raised in cold or warm environments might affect how their metabolism works once they become adults. So they reared two groups of babies, one in colder temperatures and one in warmer temperatures. They then flipped the thermostat, exposing the individuals reared in the cold to warm temperatures and the warm-reared ones to the cold.
As the researchers expected, when the temperature switched from warm to cold the animals decreased their activity levels, which the scientists were recording using infrared sensors that logged movements. This is perfectly natural for wild animals since in winter they have fewer insects to hunt and need to conserve their energy to keep from starving. In fact, in the dead of winter, antechinus can slip into a state called torpor, drastically lowering their body temperature and metabolic rates.
In the lab, the researchers also found that when turning up the heat on animals that had been reared in the cold, the animals increased their activity levels, just like they would in the wild as warmer spring temperatures bring more insects to hunt.
So far so good—until the researchers also looked at the metabolic rates, instead of just the activity levels, of the animals as they experienced temperature shifts. A metabolic rate is a measure of how much energy the animal needs to maintain function at rest. For a mammal-like antechinus, that rate can change significantly when outdoor temperatures go up or down. Unlike a reptile, a mammal-like antechinus has to constantly maintain its own body temperature, either spending energy to cool or warm itself.
This time, the researchers found that when the antechinus raised in the warm group shifted to the cold, they increased their metabolic rate only slightly. But those raised in the cold group that shifted to the warmth decreased their metabolic rate significantly. The discrepancy suggests that the babies brought up in cold conditions have more plastic phenotypes when it comes to adjusting to temperature changes.
“So we hypothesize that perhaps these results reveal that antechinus that is raised in cold conditions have more flexibility in their physiology than those that are raised in warm conditions,” says physiological ecologist Clare Stawski of University of New England in Australia and the Norwegian University of Science and Technology, lead author on the new paper. “Which might show you that in the future when it's much warmer, and more consistently warm, that the antechinus might not be as flexible to changes in the climate.”
And that’s a problem because the antechinus relies on torpor to survive the winter months. As Australia warms, this strategy may no longer be available to the species. “If it's very warm, they can't use torpor,” says Stawski. That might be fine if a warmer climate also ensures a steady supply of insects to eat all year round. “But if for some reason they lose all their food—for example, there's a fire—they might not be able to deploy torpor, and then they would really struggle to have enough energy,” she says.
Bushfires are a perfectly natural component of the Australian landscape—every so often a mild fire sweeps through an area, and these animals can take refuge underground or in fallen logs. But climate change is creating ever more powerful wildfires. Instead of gently resetting an ecosystem, they wipe it out. Even if the antechinus in the fire’s area manages to survive, the ecosystem’s insects will have been obliterated. While insect populations will eventually rebound, all the vegetation will be gone—at least in the short term—so the insects will have less food. In other words, instead of leading to a year-round insect buffet, a warmer climate might actually create more summers in which the antechinus go hungry because their food supply has been diminished by fire.
Australia has also been withering under a fierce drought; indeed, it was that lack of moisture that supercharged this season’s bushfires. Unfortunately for antechinus, food is closely linked to moisture availability, says Queensland University of Technology mammologist Andrew Baker, who wasn’t involved in this new work. “We found a decline in threatened antechinus numbers right across that drought leading up to the fires,” he says. “And that we believe is probably really closely related to lack of food availability.”
In fact, the animals’ three-week mating frenzy is so short because it’s timed with the availability of food. Females mate in the winter and give birth in the spring, when insect populations explode, providing the species with plenty of food. In the months leading up to that mating season, the males are sprinting all over the landscape, eating insects and packing on weight, since that they won’t even stop to eat once the sex frenzy starts. Once the orgy kicks off, the males’ testosterone levels skyrocket, which in turn glitches their bodies’ ability to regulate the stress hormone cortisol. An overload of this hormone makes the males’ bodies literally start falling apart. Their hair falls out, they develop open sores and they go blind, yet still stumble around in search of females.
The females, in turn, mate with as many partners as possible. Each carries sperm from perhaps dozens of males. By the time a female gives birth to around a dozen young that suckle in a depression on her belly, every adult male around her lies dead. None of them will have lived more than a year—they were all born after the previous year’s mating bonanza. Which is just as well, at least for the females and their offspring: It means more food for the mothers, who have to produce lots of highly-nutritious milk for their immature babies. (It seems bizarre, but it’s an evolutionary trade-off. Placental mammals like humans are born relatively mature but take longer to develop in the womb. In marsupials like kangaroos, babies are born less mature, but have to finish developing in the mother’s pouch.)
For the antechinus, it’s a fast life filled with drama and death, and all of it depends on being able to eat enough food and save up enough energy for the big finish. But a warmer Australia will threaten its food supply, and leave it less able to adapt to change. If only its sole worry was finding a date.
By Regan Morris & James CookBBC News, San Francisco
There's a looming crisis over the world's growing appetite for meat. Could a chicken running around a farmyard in San Francisco hold the key to a solution?
In 1931, Winston Churchill predicted that the human race would one day "escape the absurdity of growing a whole chicken in order to eat the breast or wing, by growing these parts separately under a suitable medium".
Eighty-seven years later, that day has come as we discovered at Just, a food company in San Francisco where we tasted chicken nuggets grown from the cells of a chicken feather.
The chicken - which tasted like chicken - was still alive, reportedly roaming on a farm not far from the laboratory.
This meat is not to be confused with the vegetarian plant-based burgers and other meat-substitute products which are gaining popularity in supermarkets.
No, this is actual meat grown from animal cells and variously described as cultured, synthetic, in-vitro, lab-grown or even "clean" meat.
It takes about two days to produce a chicken nugget in a small bioreactor, using a protein to encourage the cells to multiply, some type of scaffold to give structure to the product and a culture, or growth, medium to feed the meat as it develops.
The result is not yet commercially available anywhere on earth but Just's chief executive Josh Tetrick says it will be on the menu in a handful of restaurants by the end of this year.
"We make things like eggs or ice cream or butter out of plants and we make meat just out of meat. You just don't need to kill the animal," Tetrick says.
We were given a rare taste and the results were impressive. The skin was crisp and the meat flavoursome although its internal texture was slightly softer than you would expect from a nugget at, say, McDonalds or KFC.
Tetrick and other entrepreneurs working on cellular meat say they want to stop the slaughter of animals and protect the environment from the degradation of industrial factory farming.
They say they are solving the problem of how to feed a crowded earth without destroying the planet, pointing out that their meat is not genetically-modified and does not require antibiotics to grow.
The United Nations says raising animals for food is one of the major causes of global warming and air and water pollution. Even as the conventional livestock industry strives to become more efficient and environmentally friendly, many doubt it will be able to keep up with the rising global appetite for protein.
We slaughter 70 billion animals each year to feed seven billion people, says Dr Uma Valeti, a cardiologist who founded California-based Memphis Meats, a leading cell-based meat company.
He says the global demand for meat is doubling as more people rise out of poverty and that humanity won't be able to raise enough cattle and chicken to sate the appetite of nine billion people by 2050.
"So we could just literally grow any meat, poultry or seafood directly from those animal cells," Dr Valeti says. "I think that is probably much bigger than sliced bread."
Many Americans say they are eating less meat but US Department of Agriculture (USDA) figures suggest the average consumer will still consume more than 222lbs (100kg) of red meat and poultry this year - about 20lb more than they ate in the 1970s.
The pioneer of cellular agriculture is Dutch scientist Mark Post. His first lab-grown hamburger, grilled in 2013, cost $300,000 (£228,000).
No company has yet scaled-up production to serve a cell-based patty commercially but Post estimates that if he started mass producing his burgers, he could get the cost of making them down to about $10 each.
"That's of course still way too high," he said.
If Just does manage to produce enough chicken nuggets to sell this year, it is unlikely to be in an American restaurant as the US government is still deciding how to proceed.
Most food in the US is regulated by the Food and Drug Administration (FDA). But some - mostly conventionally raised meat - is regulated by the USDA. So if you're buying a frozen pizza in the US, the USDA handles the pepperoni version and the FDA handles the cheese.
"There are a number of countries in Asia and Europe that we're talking to," Tetrick says. "There's a lack of clarity" about regulations in the US while the USDA and FDA hold public hearings, he explains.
"I think countries want to take the lead in this. Whether it's food scarcity, whether it's sustainability issues or they just want to build an entirely new economy, they want to take the lead in doing this," Tetrick said.
The eventual aim is to move cellular meat out of the laboratory and into large manufacturing plants.
There are now dozens of companies working in the field and they're attracting venture capitalist investment from across Silicon Valley and beyond. Billionaires Bill Gates and Richard Branson are among those who have ploughed money into the technology.
The product also has a more surprising benefactor in Tyson Foods, which has invested an undisclosed amount in Memphis Meats.
Tyson is the biggest meat processor in the US, processing around 424,000 pigs, 130,000 cows and 35 million chickens every week. So why is it investing in cellular meat?
The firm decided "to shift from being a meat company to a protein company," said Tom Mastrobuoni, chief financial officer for Tyson's venture capital arm, Tyson Ventures.
"We've made the conscious decision that we're going to be the biggest protein company," he added.
The cutting edge technology of Silicon Valley may be synonymous with the freewheeling, entrepreneurial spirit of the United States but this is still a country where tradition runs deep.
The Cattlemen's Association has a powerful lobby and there's arguably no symbol more revered or romanticised in the nation's history than the cowboy.
And so the ranchers of the mid-west are stepping into the debate about how this new product will be marketed - as clean meat, cellular meat, slaughter-free meat, ethical protein, or just meat?
On their ranch in the Ozarks, a mountainous region extending from Missouri into Arkansas, Kalena and Billy Bruce are feeding their herd of black Angus cattle, helped by their four-year-old daughter Willa.
"I think it needs to be labelled accordingly - a lab-produced protein," says Billy Bruce. "When I think of meat I think of what's standing behind us, a live breathing animal," he adds.
The state of Missouri agrees. At the urging of farmers, the legislature has decreed that meat labels may only be applied to the product of livestock. It is a hint of the disruption which traditional agriculture feels could be on the way.
"From a transparency standpoint for consumers, so that they know what they're purchasing and what they're feeding their families, we think that it needs to be called something different," says Kalena Bruce.
Lia Biondo, the director of policy and outreach with the US Cattlemen's association, based in Washington, DC, says she expects the Missouri law could be replicated in other states.
"We will let those companies decide what to call their products just as long as they don't call it beef or meat," says Biondo.
But in any case, will anyone actually eat it, especially here in cattle country?
Diners at Lamberts, a traditional Midwest restaurant in Ozark, Missouri, are going to take some convincing.
"Meat oughta be growed on a farm, out in the fields," declares Jerry Kimrey, a construction worker from Lebanon, Missouri.
Teacher Ashley Pospisil, also from Lebanon, says she would prefer not to eat cell-based meat.
"I like to know where it came from and that it's natural and not processed from a lab," she says.
Linda Hilburn, who is tucking into a (cow) steak before heading home to Guthrie, Oklahoma agrees.
"I kind of like it having four feet in the beginning," she says.
"There's just something about man's creation that scares me. We've created havoc here. I kind of like the idea of God's creation."
While Ms Hilburn is far from alone in feeling squeamish about the idea of "Frankenstein food" as critics have labelled it, Josh Tetrick insists that cell-based meat is entirely free from the many animal diseases which plague traditional meat production.
And he is betting on human experience favouring progress.
"At the end of the day whether you're talking about a move from picking ice to refrigerator or from slaughtering a whale to refining oil into kerosene and moving from kerosene to a light bulb... even though people called the light bulb the Devil's current... humanity managed to embrace something new.
"It always happens and if I had to bet it'll happen for this too."
(There is a moral here for adults but also you might want to show uncle to your kids..adamfoxie*)
Remember Uncle Fatty, the obese monkey who was sent to a weight loss boot camp?
Well, after putting in loads of hard work and sticking to an intensive diet and exercise regimen, Uncle is finally going to be released into the wild.
The chubby macaque used to lounge around the beach-side Bang Khun Thian district in Bangkok, where visitors would constantly give him fattening food.
Thai conservation officials got involved after photos of his humongous protruding belly were shared on social media.
They tracked him down and found him hanging out with tourists in the resort, gorging on the unhealthy food he was being given.
At the time he weighed a hefty 27kg – while a normal macaque should only weigh around eight to 10 kilograms.
After confirming that he didn’t have a tumor, officials immediately put Uncle Fatty into rehabilitation.
Uncle was put on a strict diet of healthy fruits and vegetables – a big dietary change from the jellies, sugary yogurt drinks, watermelons and fizzy drinks he was given by tourists.
And this is what he looks like now!
Natanon Panpetch, a vet at the Wildlife Conservation Office, told local site Coconuts: ‘His tummy no longer drags on the ground. He is in perfect health and ready to be released. He has grown accustomed to the natural foods.’
Uncle now weighs 24.72kg – which is still big for a macaque, but it means that he’s lost around 8% of his body weight.
Officials are now discussing how they can stop people feeding the monkeys, who can easily find their own food in the mangrove.
‘A macaque is supposed to eat crabs or clams in the mangrove,’ Natanon added. ‘We do not recommend people feed the monkeys at all.
‘(Uncle Fatty) does not know what food he should not eat. He eats whatever he finds delicious.’