Geep: Behold the Sheep-Goat Chimera

Let's say you've got a sheep and a goat (and a bioengineering lab) and want to have a little fun. Why not make a geep? Geeps are created in the lab by effectively mashing up fertilized embryos from sheep and goats, then implanting the result into sheep or goat mothers. The resulting animal isn't a hybrid, it's a chimera: an animal with two genetically distinct sets of cells inside it.

Thus a geep looks like a sort of frankenpet, with patches of its body exhibiting furry goatlike features and others looking like a wooly sheep. Wikipedia has a picture of this cute (?) little fellow:

But here's where it gets nerdy. Apparently some scientists (including Dr. Gary B. Anderson of UC Davis, who provided the above photo) don't approve of the term "geep," preferring the much less catchy "sheep goat hybrid." But the term "geep" has a foothold in the popular imagination, appearing as early as 1984 in a Time Magazine article and in a recent Daily Mail article -- although the latter was referring to an entirely different kind of animal.

The Daily Mail article linked above describes something that isn't a chimera -- it's a rare natural hybrid between a goat and a sheep, created the old-fashioned way (see coverage by our friends Neatorama). Goats have 60 chromosomes while sheep have 54 chromosomes; one hybrid from Botswana, known as The Toast of Botswana, had 57 chromosomes and was infertile. For more on these true hybrids, including a picture of the Botswana animal, check out this BBC article or Wikipedia.

For more on the creation of geeps, run, don't walk, to listen to Radiolab show #404: So-Called Life. (It covers genetically engineered animals of various kinds, but includes some great geep material towards the end.)

Lastly, be careful not to use the term "shoat" when describing these animals. Although it looks like a handy conflation of "sheep" and "goat," shoat is actually a term for a baby pig. Thanks, Wikipedia!

Whale Sharks Can Live for More Than a Century, Study Finds

Some whale sharks alive today have been swimming around since the Gilded Age. The animals—the largest fish in the ocean—can live as long as 130 years, according to a new study in the journal Marine and Freshwater Research. To give you an idea of how long that is, in 1888, Grover Cleveland was finishing up his first presidential term, Thomas Edison had just started selling his first light bulbs, and the U.S. only had 38 states.

To determine whale sharks' longevity, researchers from the Nova Southeastern University in Florida and the Maldives Whale Shark Research Program tracked male sharks around South Ari Atoll in the Maldives over the course of 10 years, calculating their sizes as they came back to the area over and over again. The scientists identified sharks that returned to the atoll every few years by their distinctive spot patterns, estimating their body lengths with lasers, tape, and visually to try to get the most accurate idea of their sizes.

Using these measurements and data on whale shark growth patterns, the researchers were able to determine that male whale sharks tend to reach maturity around 25 years old and live until they’re about 130 years old. During those decades, they reach an average length of 61.7 feet—about as long as a bowling lane.

While whale sharks are known as gentle giants, they’re difficult to study, and scientists still don’t know a ton about them. They’re considered endangered, making any information we can gather about them important. And this is the first time scientists have been able to accurately measure live, swimming whale sharks.

“Up to now, such aging and growth research has required obtaining vertebrae from dead whale sharks and counting growth rings, analogous to counting tree rings, to determine age,” first author Cameron Perry said in a press statement. ”Our work shows that we can obtain age and growth information without relying on dead sharks captured in fisheries. That is a big deal.”

Though whale sharks appear to be quite long-lived, their lifespan is short compared to the Greenland shark's—in 2016, researchers reported they may live for 400 years. 

Scientists Find a Possible Link Between Beef Jerky and Mania

Scientist have discovered a surprising new factor that may contribute to mania: meat sticks. As NBC News reports, processed meats containing nitrates, like jerky and some cold cuts, may provoke symptoms of mental illness.

For a new study, published in the journal Molecular Psychiatry, scientists surveyed roughly 1100 people with psychiatric disorders who were admitted into the Sheppard Pratt Health System in Baltimore between 2007 and 2017. They had initially set out to find whether there was any connection between certain infectious diseases and mania, a common symptom of bipolar disorder that can include racing thoughts, intense euphoria, and irritability.

While questioning participants about their diet, the researchers discovered that a significant number of them had eaten cured meats before their manic episodes. Patients who had recently consumed products like salami, jerky, and dried meat sticks were more likely to be hospitalized for mania than subjects in the control group.

The link can be narrowed down to nitrates, which are preservatives added to many types of cured meats. In a later part of the study, rats that were fed nitrate-free jerky acted less hyperactive than those who were given meat with nitrates.

Numerous studies have been published on the risks of consuming foods pumped full of nitrates: The ingredient can lead to the formation of carcinogens, and it can react in the gut in a way that promotes inflammation. It's possible that inflammation from nitrates can trigger mania in people who are already susceptible to it, but scientists aren't sure how this process might work. More research still needs to be done on the relationship between gut health and mental health before people with psychiatric disorders are told to avoid beef jerky altogether.

[h/t NBC News]


More from mental floss studios