CLOSE
Richard Bartz via Wikimedia Commons // CC BY-2.5
Richard Bartz via Wikimedia Commons // CC BY-2.5

Why Worker Bees Don’t Have Babies

Richard Bartz via Wikimedia Commons // CC BY-2.5
Richard Bartz via Wikimedia Commons // CC BY-2.5

Honeybees are great. They’re important pollinators, industrious honey-makers, and they’re darn cute (just look at that fuzzy body!). But you don’t get to be as successful as they are without making some brutal choices. Those efficient, humming colonies of theirs are ruled by rigid, hierarchical laws that determine who can eat, who can leave, and who can reproduce. Exactly how those laws were enforced has long been a subject of great interest to scientists, and now one team of researchers say they’ve figured out how exactly the queen keeps her workers’ fertility in check. They published their findings in the journal Nature Communications

An individual bee’s behavior (bee-havior?) is subject to all kinds of influences, whether it be the waggle dance of a returning forager, the electrical messages put out by a flower, or the many chemical signals drifting through hive air. One notable signal is queen mandibular pheromone, or QMP. QMP is an astonishingly versatile compound. It tells drone bees when the queen is ready to mate, induces the colony to swarm, and can destroy the ovaries of worker bees to keep them from getting busy. Pretty impressive, right? 

Previous studies in fruit flies had found a link between the flies’ egg production and a cellular pathway called the Notch. To find out if the same pathway had any involvement in honeybees' egg shutdown, evolutionary biologists at New Zealand’s University of Otago treated some workers with a chemical that suppressed any Notch activity and left other workers’ Notch signaling intact. Then all the bees were exposed to typical levels of QMP. The researchers killed the bees, then examined their ovaries to see what had happened. 

Sure enough, the ovaries of bees with normal Notch function were damaged by the QMP. But before their deaths, the blocked-Notch bees had been humming along just fine; many of their ovaries contained fully developed eggs.

Additional tests on the bees confirmed a strong bond between Notch and QMP. When worker bees were left to their own devices and not exposed to a queen or her pheromones, their Notch receptors gradually degenerated. Without a queen, the workers' fertility was unfettered.

The researchers were surprised to see just how early in the reproductive process Notch could make a difference. Speaking in a press statement, co-author Peter Dearden said they’re still not sure if the pheromone attacks the ovary directly or works through the brain.

"However it is acting, the outcome is that Notch signaling's fundamental role in the ovary has been modified and transformed in honeybees into social control of worker bees' reproduction," he said. 

Know of something you think we should cover? Email us at tips@mentalfloss.com.

nextArticle.image_alt|e
iStock
arrow
Animals
Slow Motion Is the Only Way to Appreciate a Chameleon’s Lightning-Fast Tongue
iStock
iStock

From the unusual way they walk, to their ability to change color, the evolutionary adaptations of chameleons are pretty bizarre, and some of them remain mysterious even to scientists. Their super-powered tongues, for instance, can dart out so quickly that the movement can barely be seen with the naked eye. But modern high-speed cameras have enabled researchers at the University of South Dakota to observe this appendage at work like never before. The video below, shared over at The Kid Should See This, includes some of that groundbreaking footage, and it's pretty amazing to watch.

Shooting at 3000 frames per second, the camera was able to capture every split-second aspect of the chameleon's tongue strike. Slowed down, the video allows you to see how every component of the process works in harmony: First, muscles in the lizard’s tongue contract like the string of a bow. Then, when that tension is released, the bony base of the tongue shoots forward, pushing the sticky, elastic part toward the chameleon’s prey.

According to Christopher Anderson, one of the scientists who conducted the high-speed camera research, larger chameleons can catapult their tongues forward at distances of one to two times their body length. For smaller chameleons, this distance can reach up to two and a half times their body length. “Small chameleons need to be able to eat more food for their body size than large chameleons,” he tells bioGraphic in the video, “and so by being able to project their tongues proportionately further than these large species, they basically are opening up additional feeding opportunities to themselves that they wouldn’t have if they had a shorter tongue.”

To see one of nature’s greatest hunting tools in action, check out the full video below.

[h/t The Kid Should See This]

nextArticle.image_alt|e
iStock
arrow
science
There May Be an Ancient Reason Why Your Dog Eats Poop
iStock
iStock

Dogs aren't known for their picky taste in food, but some pups go beyond the normal trash hunting and start rooting around in poop, whether it be their own or a friend's. Just why dogs exhibit this behavior is a scientific mystery. Only some dogs do it, and researchers aren't quite sure where the impulse comes from. But if your dog is a poop eater, it's nearly impossible to steer them away from their favorite feces.

A new study in the journal Veterinary Medicine and Science, spotted by The Washington Post, presents a new theory for what scientists call "canine conspecific coprophagy," or dogs eating dog poop.

In online surveys about domestic dogs' poop-eating habits completed by thousands of pet owners, the researchers found no link between eating poop and a dog's sex, house training, compulsive behavior, or the style of mothering they received as puppies. However, they did find one common link between the poop eaters. Most tended to eat only poop that was less than two days old. According to their data, 85 percent of poop-eaters only go for the fresh stuff.

That timeline is important because it tracks with the lifespan of parasites. And this led the researchers to the following hypothesis: that eating poop is a holdover behavior from domestic dogs' ancestors, who may have had a decent reason to tuck into their friends' poop.

Since their poop has a high chance of containing intestinal parasites, wolves poop far from their dens. But if a sick wolf doesn't quite make it out of the den in time, they might do their business too close to home. A healthier wolf might eat this poop, but the parasite eggs wouldn't have hatched within the first day or two of the feces being dropped. Thus, the healthy wolf would carry the risk of infection away from the den, depositing the eggs they had consumed away in their own, subsequent bowel movements at an appropriate distance before the eggs had the chance to hatch into larvae and transmit the parasite to the pack.

Domestic dogs may just be enacting this behavior instinctively—only for them, there isn't as much danger of them picking up a parasite at home. However, the theory isn't foolproof. The surveys also found that so-called "greedy eaters" were more likely to eat feces than dogs who aren't quite so intense about food. So yes, it could still be about a poop-loving palate.

But really, it's much more pleasant to think about the behavior as a parasite-protection measure than our best pals foraging for a delicious fecal snack. 

[h/t The Washington Post]

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios