WTF Fun Fact 12771 – The Saraha Desert Forest Mystery

Ok, trigger warning: There’s a high chance of getting Toto’s “Africa” stuck in your head by reading this post. But, the truth is, there used to be plenty of rains down in Africa. Enough to have made the Saraha Desert a rainforest.

It’s not a huge shock, since we know the Earth has gone through different climatic periods, but this was one far more recent and accounts for a more radical change than scientists ever could have imagined. In other words, it really takes a lot to turn a vibrant forest into a bone-dry desert, and this happened a mere 6000ish years ago! It’s pretty interesting.

How did the Sahara go from forest to desert?

So, what’s the deal here? Well, since we don’t have a time machine, we can’t know for certain. It could have to do with the tilt of the Earth’s orbital axis changing, it could also be part of a longer, larger pattern of transition.

African Humid Periods in the distant past meant….you guessed it…more rains down in Africa. In particular, northern Africa (which is where the Sahara is, in case you don’t have a map handy). But at some point, those rains went away.

As Smithsonian Magazine (cited below) explains:

“With more rain, the region gets more greenery and rivers and lakes. All this has been known for decades. But between 8,000 and 4,500 years ago, something strange happened: The transition from humid to dry happened far more rapidly in some areas than could be explained by the orbital precession alone, resulting in the Sahara Desert as we know it today.”

Cool use of archaeological data

We can see from archaeological data (which is not perfect, but is overwhelmingly in favor of showing past water and trees in certain areas) that the area was once forest, and even rainforest. But what’s also interesting – and seals the deal for most people – is that in this period there is also evidence of pastoralists. That means people were raising and herding animals. And you definitely can’t do that in a desert.

Are humans to blame?

If it wasn’t solely an axial issue (regarding the Earth’s tilt), some scientists believe that humans could have played a big role in changing the climate due to overgrazing.

There have been suggestions that the end of the humid period in northern Africa could have been brought about by humans letting domesticated animals eat up all the moisture-loving plants. They would have probably had to use fire as a land management tool as well. And that may have been enough to trigger the big change that turned the forest into a desert.

It’s not that easy, of course, but that’s the general idea. There are also hypotheses that humans had nothing at all to do with it. And neither one of those would be related to whether or not humans are affecting the climate currently, so it’s not a political discussion (thankfully).  WTF fun facts

Source: “What Really Turned the Sahara Desert From a Green Oasis Into a Wasteland?” — Smithsonian Magazine

WTF Fun Fact 12764 – Mindfulness Meditation Changes the Brain

We need more large-scale studies to make definitive claims, but mindfulness meditation seems to have some cool cognitive benefits. In fact, we can see on brain scans that people who practice mindfulness meditation experience changes in their brains.

Minding your thoughts

Mindfulness practice encourages people to stop and spend time noticing their thoughts and then letting go of the ones that are negative, disorganized, or aren’t serving a positive purpose. It’s designed to help us notice and control our thinking. (As opposed to most meditation practices, which center around emptying the mind of thoughts.)

The part of the brain affected by mindfulness practice is called the amygdala. This is also called the “fight or flight” center because it is linked to fear and emotional responses. Brain scans have shown that mindfulness practice helps shrink the amygdala. While that may sound like a bad thing, an overactive amygdala can be bad for concentration, mood, and emotional regulation.

Regulating the amygdala

However, mindfulness has been shown to help increase the connections between the amygdala and prefrontal cortex. That’s a good thing because those connections help us regulate our emotional responses.

We need our amygdala, we just don’t want it to be hyperactive. And when we practice mindfulness, our bodies get better at regulating those emotional responses.

While some of the effects of mindfulness have been overstated in the press, there is evidence that it can modestly increase physical health and compassion and even reduce bias in addition to negative thought patterns.

The popularity of mindfulness meditation

A U.S. survey found that the percentage of adults practicing some type of mantra-based meditation, mindfulness meditation, or spiritual meditation in the previous year tripled between 2012 and 2017 (from 4.1% to 14.2%). Even among children (4 to 17 years of age), the percentage increased from less than 1% to over 5%. These emotional regulation techniques continue to grow in popularity.

Of course, there’s a lot we still don’t know about mindfulness and meditation in general, and they’re not always the best practices for everyone.

There are also different types of mindfulness meditation to practice, each with slightly different outcomes. For example, body scanning can help reduce negative thoughts. But practices in which participants are asked to observe their thoughts can sometimes lead to more negative thinking, especially among those who have just started practicing the skill and can’t let go of those thoughts easily.

In the end, it may be best for those who are new to mindfulness and observing their thoughts to do so with guidance from a teacher or tool so that they can stay on the right track and get the most out of their mindfulness practices.  WTF fun facts

Source: “10 Things We Know About the Science of Meditation” — Mindful

WTF Fun Fact 12753 – The Rarity of Green Eyes

We knew green eyes were rare, but they seem even more special knowing that only 2% of people in the world have them.

Green-eyed people are everywhere

But if your friend tells you their newborn has green eyes, they’re clearly seeing something different. All babies are born with some shade of brown or blue eyes. As their eyes are exposed to more light over time, their eye color begins to change into what their own unique genetics dictates. But this can take up to three years!

It may be no surprise that most people with green eyes can be found in Ireland, Scotland, and Northern Europe (or they’re descendants of people from that area). The red hair-green eye combo is pretty classic. However, anyone can technically have green eyes, including people who are Black, Arabic, Hispanic/Latino, etc.

If you were to guess the country with the most green-eyed people, would you choose Ireland? We would have. But, in fact, Iceland is the country with the largest population of green-eyed people. in fact, over 80% of Icelanders have blue or green eyes.

The myth of the Punnett square

Another interesting thing about eye color is that it’s not as simple as we learned in high school biology (remember Punnett squares?!). Genetics plays a role, but the contribution of different genes to our melanin cells (the cells that give our skin and eyes their pigment) is more complicated than we were taught. So don’t break out the paternity test as soon as you see an unexpected eye color. Even two parents with blue eyes can have a brown-eyed child!

Eye color is actually a polygenic trait (whereas Punnett squares would have had us believe it just took two genes and no more).

People with blue eyes have genes that produce the fewest melanin cells. Green-eyed people have more melanin in their eyes than blue-eyed people. But it’s the combination of that along with the presence of a yellow pigment called lipochrome that makes eyes appear green.  WTF fun facts

Source: “12 Mind-Blowing Facts About Your Body” — Newsweek

WTF Fun Fact 12749 – The Invention of Kidney Dialysis

The development of kidney dialysis started centuries ago. Even doctors in the ancient world understood the kidneys played an important role in filtering bodily fluids. Galen’s treatise On the Natural Faculties mentioned doctors prior to his time investigating the organ and its function.

But figuring out how to replicate the filtering function of the kidneys didn’t happen until the 1800s when a Scottish chemist named Thomas Graham realized he could create a membrane to act as a filter to “clean” some bodily fluids (though he wasn’t exactly spot on about what he was filtering out).

Despite sometimes being referred to as the “Father of Dialysis,” his discoveries weren’t kidney-related. In fact, for decades, scientists were more concerned with trying to filter blood for trauma patients during surgery. That’s because they didn’t have blood banks, so when someone lost blood, they needed to preserve it for the patient but also needed a way of cleaning it up first.

Blood dialysis was performed on animals in the early 20th century, and the use of blood thinners was already in use to keep it from clotting (which is necessary if you want to put it back in the body!).

In 1924, a German doctor named Georg Haas realized the possibilities of dialysis for kidney patients. Since our kidneys are responsible for filtering out impurities, those in kidney failure need some extra help.

Haas seems to have had around six patients that used his dialysis machine, but it wasn’t quite ready for prime time yet. All of those patients died of kidney failure (possibly as a result of the dialysis not filtering adequately).

The “drum kidney” was introduced in 1945 by a Dutch doctor Willem Kolff, and because materials science was more advanced, the plastics and other materials he had at his disposal made the machine more effective for cleaning bodily fluids (and didn’t leach its own materials into patients either).

Before we get to today’s modern-day dialysis machines, there were many more people involved in the invention of dialysis – including chemists and physicians that improved upon past technology:

– Swedish chemist Nils Alwall designed a machine to both clean and drain blood
– American scientist Belding Scribner had the dialysis process uninterrupted so the body would not be severely lacking in blood during the dialysis treatment
– Michael Brescia and James Cimino found a way to make Scribner’s invention work with needles so patients didn’t need to maintain an open wound that might be prone to infection

And these are just the preliminary steps we took on our way to modern kidney dialysis!

 WTF fun facts

Source: “History of the kidney disease treatment” — St. George’s Kidney Patients Association

WTF Fun Fact 12748 – Koala Bears Have Fingerprints

Koala bears have fingerprints just like apes and humans. This is surprising since our last common ancestor lived over 100 million years ago.

Nevertheless, koalas have retained their unique fingerprints.

We tend to think of fingerprints as solely a product of our criminal justice system. And yet, those little lines on our fingers actually serve a purpose besides putting us at a crime scene.

The purpose of fingerprints

Our fingerprints help us grab and feel objects, and researchers believe they help our sense of touch. This isn’t so important to us anymore, but it is helpful to animals who can use touch sensations to judge whether leaves, for example, belong to the right tree.

Our fingerprints actually cause little vibrations when we run them over objects. And since koalas really only eat eucalyptus, they like to be sure they’re in the midst of the right kind of buffet before they start chowing down.

Fingerprints are unique

Since you can’t really tell a koala’s fingerprint from a human’s, at least in terms of patterns, they may be the perfect sidekick for a crime scene. There’s no koala bear fingerprint database, so you can pretty much just let them touch everything to upend an investigation (just kidding – don’t try this at home – or anywhere else for that matter).

However, if a koala at a zoo has committed a crime, theoretically, you could fingerprint the residents to figure out whodunnit. We don’t think that’s ever been a necessity, but it sounds like a good premise for a children’s crime novel (if those existed).

Koalas bears have fingerprints and other animals have…

While koala bears have human-like fingerprints, other animals have identifying marks on their paw pads as well.

According to New Scientist (cited below):

Individual cats and dogs, for example, have unique whisker patterns. Zebras have distinct stripe arrangements and individual leopards and spotted dolphins have their own spot patterns. Humpback whales also have unique markings on the underside of their tails.”

Who knew?  WTF fun facts

Source: “Do other animals have fingerprints? And what purpose do they serve?” — New Scientist

WTF Fun Fact 12747 – Flamingos Eat Upside Down

Because of the way their heads and beaks are built, flamingos eat upside down. Well, at least that’s how their heads are positioned.

Flamingo beaks scoop up water in the areas where they feed. Then, that water is processed through a structure called the lamellae, which acts as a filter. It ensures that water, sand, and other less tasty things are then expelled back into the water while the marine creatures (such as shrimp and brine flies) that flamingos eat are trapped inside. (Another fun fact: this food is also what makes flamingos pink!)

Flamingo anatomy

A flamingo’s tongue is designed to push the water back out through these filtration mechanisms.

According to the San Diego Zoo, “Greater and Chilean flamingos are larger and feed mostly on invertebrates such as brine flies, shrimps, and mollusks. They get these food items from the bottom mud by wading in shallow water. Sometimes they swim to get their food and sometimes by ‘upending’ (tail feathers in the air, head underwater) like ducks.”

It all happens quite fast, but if you take a look at how a flamingo is built, you’ll see that eating upside down is really the only way.

Of course, flamingos breathe air, which means that while they’re attempting to feed, they need to hold their breath – something they can do for up to a few minutes at a time. They need to poke their heads up every now and then to get more oxygen.

Flamingos eat upside down even on a zoo diet

According to the zoo, their flamingos get a special diet with all the nutrients they need. But even in these cases, they still use the same upside down stature to take in their food:

“At the San Diego Zoo and the San Diego Zoo Safari Park, the flamingos are fed a special pellet diet that is made for zoo flamingos. This food has all the nutrients the flamingos need and a pigment that helps keep them “in the pink.” To allow the flamingos to eat in their normal way (taking in water and then pumping it back out), a water source just for feeding is near their food so they can get a “beakful” of water and then food—just like they would in the wild.”

Flamingo mysteries

Flamingos are interesting creatures and there are still some habits we can’t explain – such as why they sometimes stand on one foot. No one has definitively explained that behavior yet. – WTF fun facts

Source: “Flamingo” – The San Diego Zoo

WTF Fun Fact 12743 – Laughter is the Best Medicine

We’ve always had lots of anecdotal evidence that “laughter is the best medicine” and studies have shown correlations between laughter and happiness and laughter and better life satisfaction. But in 2005, the first study showed some of the physiological effects laughter has on the body’s cardiovascular system.

So when you say “laughter is the best medicine” to someone and they roll their eyes, you can now hit them with some facts (unless you’re at a funeral or something, then wait a few weeks, please).

The first study

The results of the study were first presented at the Scientific Session of the American College of Cardiology, on March 7, 2005 by researchers from the University of Maryland. It kicked off a whole slew of studies backing up the evidence and providing yet more clues that you can laugh your way into old age.

But first, let’s see how this works. The first study used movies to look at the immediate effects of laughter on subjects’ endothelium – the tissue that forms the inner lining of blood vessels and that dilates or expands during blood flow. (And if it’s been a while since you’ve had a biology class, the better blood flows around your body – and to your heart – the more oxygen and other vital molecules get where they need to be.)

The approach

There were two groups of subjects – one watched a movie clip known to cause mental distress (for example, scenes from Saving Private Ryan – a great film, but not exactly a “cinematic joy ride,” aka it’s sad). The other group watched scenes from funny movies (one example was King Pin, which we have never seen, but we’ll trust that the researchers found a good clip).

Ok, so the goal was really just to make one group laugh and the other get kind of mired in sadness and then measure their blood flow. And you can probably see where this is going.

The results

The distressed group’s blood vessels showed an unhealthy physiological response of the blood vessels called vasoconstriction (a narrowing of the vessels that impedes blood flow). That had been suggested by many other studies before – when we’re stressed, our blood vessels constrict. Not good.

On the other hand, those who laughed showed great blood flow. That’s good. But it’s not just good in the moment, it’s good in the long term because the endothelium helps tone our blood vessels, adjust coagulation rates, and secretes chemicals that help heal wounds and respond to infections.

The researcher’s commentary

In an interview about the study, the lead investigator Michael Miller, M.D., director of preventive cardiology at the University of Maryland Medical Center said: “The endothelium is the first line in the development of atherosclerosis or hardening of the arteries, so, given the results of our study, it is conceivable that laughing may be important to maintain a healthy endothelium, and reduce the risk of cardiovascular disease. At the very least, laughter offsets the impact of mental stress, which is harmful to the endothelium.”

The impact of laughter was so strong that they compared it to the benefits one may get from exercise (thought warned against trying to replace exercise with laughter).

“The magnitude of change we saw in the endothelium is similar to the benefit we might see with aerobic activity, but without the aches, pains and muscle tension associated with exercise,” Miller said. “We don’t recommend that you laugh and not exercise, but we do recommend that you try to laugh on a regular basis. Thirty minutes of exercise three times a week, and 15 minutes of laughter on a daily basis is probably good for the vascular system.”

Further evidence

Since 2005, there have been many studies that show laughter is good for health, including:

  • A study of older Japanese people which found that those who laughed more had fewer heart attacks and stroked.
  • A 2020 study showing that overall mortality, as well as cardiovascular disease, were significantly higher among subjects with a low frequency of laughter.
  • A review essay noting that “many kinds of studies, using different methods, conclude that happiness has a positive causal effect on longevity and physiological health.”

So, ask your doctor today about what a funny movie or a night out with fun friends can do for you. And if they look at you funny, just tell them you read that laughter is the best medicine on the internet. They love hearing that. – WTF fun facts

Source: “Laughter Helps Blood Vessels Function Better” — Science Daily

WTF Fun Fact 12740 – The Master Switch of Life

The Master Switch of Life is a phrase coined by Swedish researcher Per Scholander in the 1960s.

His research took place in the U.S. the United States where he studied just how being underwater would affect humans. He had already studied Weddell seals and found that the creatures seemed to gain more oxygen the longer they were underwater.

The water tank trials

To see if the effect might be the same in humans, he put volunteers in a water tank and monitored their heart rates as they dove to the bottom of the tank. Immediately, the volunteers’ heart rates decreased.

Then he asked them to do some exercise at the bottom of the tank to try and raise their heart rates but to no avail. Being underwater continued to lower everyone’s heart rate, meaning they also needed less oxygen (the opposite of what happens on land when we exercise). In addition, when the volunteers were underwater, their blood began flowing away from limbs and towards vital organs (which also happens in seals).

When blood flows to the heart and brain, they stay oxygenated longer, meaning we need less overall oxygen for our bodies to continue to function.

The mystery of water

That’s when he wondered why water has such an unexpected effect on us.

It turns out that the more we dive, the more blood can penetrate the cell walls of our organs to counteract external pressure.

And here’s the really cool part, according to TED:

“Scholander found that a person need submerge only his face in water to activate these life-lengthening (and lifesaving) reflexes. Other researchers tried sticking a hand or a leg in the water in an attempt to trigger the reflex, but to no avail. One researcher even put volunteers into a compression chamber to see if pressure alone would trigger a similar diving reflex. No dice. Only water could trigger these reflexes, and the water had to be cooler than the surrounding air.”

A splash of cold water

All we need to do is splash some cold water on our faces to flip what he called this “Master Switch of Life.” Cool water basically makes us more amphibious and produces a physical change in our heart rates. That certainly explains why cold water feels so refreshing!

 WTF fun facts

Source: “Your body’s amazing reaction to water” — TED Ideas

WTF Fun Fact 12739 – The Dreams of Men

Multiple studies have shown tend to have more male characters in their dreams.

We have very little control over what we dream about, even though many of us try to direct our dreams. (I know I do – if I could spend all night dreaming about being a wealthy villa owner on an abandoned tropical coast instead of reliving a made-up scenario about missing a vital exam and never graduating high school, I would!)

Studying dreams

Anyway, there are hundreds of studies on dreams. Most of them involve having people use dream journals where they write down the contents of their dreams any time they awaken. The journals are then processed by a researchers who looks for certain characteristics without knowing anything about the person the journals belong to (that’s why they’re called a “blind judge” in many research papers).

Researchers usually start with common themes and types of characters and count mentions of them. And a lot of the research has backed up the data we’ve collected over time. (However, there are some differences between cultures as to what we dream about.)

Demhoff’s dream research

For example, G. William Domhoff wrote one of the most widely-cited papers on the genders we dream about (nearly two decades ago, before talking about more than two genders was a cultural priority). It’s called “The Dreams of Men and Women: Patterns of Gender Similarity and Difference,” and it was published in 2005.

In the paper, Domhoff is very clear that “The study of gender similarities and differences in dream content has proven to be a dangerous mine field for dream researchers.” That’s because this kind of information has the “potential to stir up all the tensions that inevitably accompany any discussion of gender in a world where gender discrimination–and conflicts between men and women on many personal issues–are pervasive.”

Limited interpretations

In other words, it’s likely that a large number of people will dislike this “fun fact” because they somehow feel judged by it or don’t like whatever they think it implies (which is largely nothing).

Demhoff was also careful to not that variations across cultures and across genders make generalizations difficult. He’s just reporting on one characteristic that he found to be statistically significant – the gender of the characters in people’s dreams.

Demhoff concentrated on American subjects since he was most familiar with the cultural characteristics of Americans. But other researchers have studied other cultures and found some key differences.

To make sure everyone is categorizing things in a roughly similar way, Demhoff used a coding system developed in 1966 called the Hall/Van de Castle system, where most things fall into pretty simple categories like: men/women; indoor setting/outdoor setting, etc. But that system was created based on the dream journals of white, middle-class college students at Case Western in the 1950s and 60s. In general, other studies have found these categories useful too.

So, on to the results (because results don’t mean much without some context first!).

What men dream of

Demhoff asked what percentage of dreams had a negative element “such as aggressions, misfortunes, failures, and negative emotions (anger, apprehension, confusion, and sadness)…” And the results were that “men and women are similar in that 80% of men’s dreams and 77% of women’s have at least one of these negative elements.”

When it comes to positive aspects, “such as friendly interactions, good fortune, success, and happiness, 53% of dreams for both men and women have at least one of those elements. Men and women also have an equal number of dreams in which food or eating is mentioned–about 17%.”

In addition, “Both men and women are more often victims than aggressors in the aggressive interactions in their dreams, and they face the same attackers, namely, men who are not known to them (“male strangers”) and animals. On a more positive note, both men and women are equally likely to befriend another character in their dreams.”

But we started with the most reported-on finding, which is that “men dream twice as often about other men as they do about women (67% vs. 33%), and women dream equally about both sexes (48% men, 52% women).”

What’s implied by the dreams of men? Not much

And here’s where people get offended. No one is implying that men fantasize about other men. They can be someone you fight on the street, your 5th grade math teacher, your dad…whatever.

Women may also have more of a character gender balance because their dreams tend to have more characters overall. This may be a result of women’s dreams being longer overall than men’s.

But Demhoff points out that this in not universal. Even among Black Americans, men and women tended to have an equal gender breakdown in dreams. Studies of Mexican and Peruvian teens as well as German college students also showed more of a gender balance. However, in each case there were slightly more men than women in everyone’s dreams.

 WTF fun facts

Source: “The Dreams of Men and Women: Patterns of Gender Similarity and Difference” — G. William Domhoff