Why Are Lemurs So Weird? Maybe Because They Don't Eat Enough Fruit

Luca Santini
Luca Santini

Lemurs are weird animals. Found only in Madagascar, they're primates (like apes, gorillas, and us), but unlike all other primates, they do things like hibernate and sleep in caves—that is, when they sleep, because they don't follow the normal nocturnal/diurnal pattern. Oh, and unlike many primates, most of them aren't frugivores. Meaning, they don't eat fruit. Their diet is much heavier on leaves than other primates.

A new study in the journal Scientific Reports suggests a reason why: The fruit available on the island doesn't have enough protein in it to meet their dietary needs, so they evolved a diet that didn't include it. The researchers, an international team led by Giuseppe Donati of Oxford Brookes University, combed through 79 different studies to analyze the nitrogen content (a necessary component of protein) of fruits cross the world and compare the rates of primate communities who eat fruit in different regions.

The higher the protein content of the fruits found in an area, they discovered, the more the animals relied on them as a food source. The fruits of Madagascar are also lower in nitrogen than fruits elsewhere, and in turn, the number of lemur communities in Madagascar that eat fruit is significantly lower than the number of primates in the Western Hemisphere, Asia, or elsewhere in Africa that eat fruit. (Only two genera of lemur subsist mainly on fruit, while elsewhere in the world, even primates that eat leaves still enjoy a good fruit salad now and then.)

"Lemurs are equal parts ridiculously cool and totally bizarre in that they represent the extremes and the extremely strange in the primate world," the Field Museum's Abigail Derby Lewis, a senior conservation ecologist, said in a press release. And studying their dietary patterns suggests why they've evolved to be so strange in comparison to their other primate relatives. Unable to get protein from fruit, they had to eat more leaves. To eat more leaves, their sleep schedules had to accommodate round-the-clock eating, which would explain their odd sleep patterns. And to conserve energy, they go into hibernation.

Lemurs aren't the only primates that go for leaves over fruit. So do howler monkeys. A March 2017 study found that primates that do eat fruit tend to have bigger brains. Nutritious fruit might not be the sole factor determining how primate species evolve, but it's clear that having access to it matters significantly. 

Why Is Pee Yellow?

Chloe Effron
Chloe Effron

WHY? is our attempt to answer all the questions every little kid asks. Do you have a question? Send it to why@mentalfloss.com.

Your body is kind of like a house. You bring things into your body by eating, drinking, and breathing. But just like the things we bring home to real houses, we don’t need every part of what we take in. So there are leftovers, or garbage. And if you let garbage sit around in your house or your body for too long, it gets gross and can make you sick. Your body takes out the garbage by peeing and pooping. These two things are part of your body’s excretory system (ECKS-krih-tore-eee SISS-tem), which is just a fancy way of saying “trash removal.” If your body is healthy, when you look in the toilet you should see brown poop and yellow pee.

Clear, light yellow pee is a sign that your excretory system and the rest of your body are working right. If your pee, or urine (YER-inn), is not see-through, that might mean you are sick. Dark yellow urine usually means that you aren’t drinking enough water. On the other hand, really pale or colorless pee can mean you might be drinking too much water! 

Your blood is filtered through two small organs called kidneys (KID-knees). Remember the garbage we talked about earlier? The chemicals called toxins (TOCK-sins) are like garbage in your blood. Your kidneys act like a net, catching the toxins and other leftovers and turning them into pee.

One part of your blood is called hemoglobin (HEE-moh-gloh-bin). This is what makes your blood red. Hemoglobin goes through a lot of changes as it passes through your body. When it reaches your kidneys, it turns yellow thanks to a chemical called urobilin (yer-ah-BY-lin). Urobilin is kind of like food coloring. The more water you add, the lighter it will be. That's why, if you see dark yellow pee in the toilet, it's time to ask your mom or dad for a cup of water. 

To learn more about pee, check out this article from Kids Health. 

Flashing Status Symbols Won’t Impress New Friends—and May Even Backfire


Trying to keep up with the Joneses isn’t a very effective way of making friends. As The Outline reports, a recent study in the journal Social Psychological and Personality Science suggests that flashing status symbols makes people less likely to want to be your friend.

While some may feel like sporting a luxury watch or designer clothes will draw people toward them, it actually does the opposite, making you a less attractive potential friend, according to a trio of researchers from Michigan, Singapore, and Israel. Over the course of six different experiments, the researchers found that study participants tended to think that high-status markers like fancy cars would help them make new friends. The trend stayed true across both participants recruited using Amazon Mechanical Turk and upscale shoppers stopped for a survey in a high-income suburb.

People thought that showing up to an outdoor wedding in a luxury car or going out to a downtown bar wearing a fancy brand-name watch would lead people to be more attracted to them as potential friends, compared to someone driving a basic car or wearing a generic watch. Yet participants also rated themselves as being more willing to befriend someone with generic clothes and cars than someone who flashed designer goods.

The paradox makes a little more sense if you go back to the idea of “keeping up” with our neighbors. People want to look high status in comparison to others. They don’t want to hang out with people who are flashing around luxury goods—they want to be the flashier ones.

[h/t The Outline]


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