When we were kids, my three siblings and I had an understanding that when we were feeling sick in the middle of the night, we needed to wake my mom. If there was any indication that we might vomit, we headed for her side of the bed and let my dad sleep. It wasn’t that my dad wasn’t willing to help, it was just more of a mess if he got involved. He had very little control over his gag reflex and if one of us started to get sick in his presence, he’d make an immediate run for the nearest trash can and start vomiting too. I’m sure my mom often wished she wasn’t the only parent on puke duty, but I doubt it ever crossed her mind that my dad might actually be more evolved. According to one popular theory about social vomiting, vomiting when someone else is puking may be an evolutionary development (and those who are prone to social vomit might be more evolved). Ancient cultures, like pastoral tribes that moved from place to place, were believed to engage in a practice of forcefully making themselves vomit if another member of their group threw up. As gross as it might sound, this practice was based in a desire to protect the whole group from a case of poisoning, according to Medical Life Sciences News. It is believed that with time, the human body adopted this function as a means of survival. And also with time, throwing up anytime we see, hear, or smell vomit became an automatic, uncontrollable urge. Sure, throwing up is totally disgusting, but it definitely makes sense as a protective behavior, especially for members of social groups that were constantly moving and being exposed to new varieties of food. The body has a tendency to work this way—adapting to the environment over time as a means of survival. Here are a few other amazing, weird, and even gross bodily functions humanity developed for good reason.
1. Our body is home to countless microorganisms.
Although it might not make sense at first, there is a lot of benefit to having tons of bacteria present in the human body. The presence of trillions of bacteria in the body isn’t an accident either, according to Scott Anderson, author of The Psychobiotic Revolution, a book that explores the role gut bacteria play in mental health. “They are there to protect you from rapidly changing pathogens in the environment. Humans can’t change genes fast enough to keep up, so they conscripted a group of quickly evolving microbes to do the job for them,” he explains. Not only do many scientists say the microbiome present in the gut is its own organ, they are also certain its presence is essential to human health. A healthy gut—one that has plenty of good bacteria—has long been said to promote digestive health and is now believed to be linked to mental health as well, according to the journal Gastroenterology & Hepatology.
2. Our body does this to protect us from injury.
Don’t feel bad if you’ve ever fainted at the sight of blood. Many scientists believe this reflex is just one of the ways our bodies have evolved for the sake of survival. That light-headed feeling that may cause you to faint at the sight of blood is called vasovagal syncope, and it happens when we experience a drop in heart rate and blood pressure at the same time, according to Psychology Today. Apparently, one commonly held theory is that vasovagal syncope developed to protect humans from injury. It’s a two-part theory, the first part being that slow blood flow would result in slower bleeding out in case of injury. The second part of the theory is the assumption that this was a response that developed in civilizations that were regularly at risk of being harmed by other humans or wild animals. The assumption is that by seeing others harmed and bleeding then passing out, other humans could avoid harm by appearing dead.
3. Our skin problems may be preparing us for parenthood.
I know from personal experience just how agonizing and embarrassing acne during adolescence can be. I battled full face breakouts from 15 years old until I turned 21, and it wasn’t just unsightly, it was painful, too! Imagine my disbelief when I read that some scientists actually believe skin breakouts are a blessing to adolescents, not a curse. According to one evolutionary theory published in the journal Medical Hypothesis, adolescents might develop acne to keep them from procreating until they are mature enough to be parents. Yes, really, that unsightly breakout on your preteen’s face might be playing a role in keeping him abstinent. The idea is that acne is just gross enough to turn off potential mates and that this might prevent teens from becoming sexually active, which is thought to prevent some kids from becoming parents until they’ve grown up a little, or at least matured enough to make better choices about their sex lives.
4. This reflex might be meant to save us from drowning.
Even though most humans, including myself, spend the majority of our days on dry land, we have an amazing reflex that is believed to be meant to save us from drowning. The mammalian dive reflex is the body’s response to a cold stimulus, like water, touching our face. Our body responds to the feeling of cold on our snouts by decreasing our heart rate and sending the blood in our body to our core to support the brain and the heart. “All of this occurs the instant the face hits the cold stimulus. The reflex allows the conservation of oxygen and support of the most important structures in the body: the brain and the heart, as the body makes the judgement to go into survival, preservation, or calm mode,” explains Dr. Anthony C. Warren, a breathing expert and CEO of BreatheSimple.
5. The Body Part Only Half of the Population Needs
Have you ever wondered why both men and women have nipples, when only women have a practical purpose for them? Men don’t breastfeed, so why not skip the nipples altogether? It’s all about the way humans develop after conception, according to LiveScience. The fact of the matter is that, during those first weeks of development, both men and women develop exactly the same. These rapidly developing embryos use the same genetic blueprint, nipples included. Around six or seven weeks, the presence of the Y chromosome causes a differentiation between women and men. Those embryos with a Y chromosome begin to develop male sex organs, but the nipples stay. Still, without the presence of estrogen in the body, their chests remain flat after adolescence.
6. This useless body part might actually have a purpose.
The human body evolves in response to the environment for the sake of survival and sometimes this means once valuable functions aren’t so necessary anymore. Since Darwin, evolutionary biologists believed the appendix was an “evolutionary artifact” once used to help humans who were eating low-quality and raw foods. These days, doctors will still remove a ruptured appendix without so much as a second thought. However, newer research suggests there might actually be a purpose for the appendix, according to Science Daily. The hypothesis is that the appendix is home to a boatload of healthy bacteria, keeping them close at hand to replenish the gut if something goes awry, like a nasty case of diarrhea.
7. Our skin reacts when we’re cold or a little scared.
Has is ever crossed your mind how weird it is that humans get goosebumps when we’re cold, scared, or even after hearing someone belt out the national anthem? It might be so common that we’ve never thought to question it, but the origin of this bodily function is certainly interesting! Long story short, adrenaline is behind the goosebumps we experience. Adrenaline is one of our body’s responses when we experience something that triggers our fight-or-flight response. This could happen for a variety of reasons, maybe during a stressful event, when something is emotional, or when we experience a novel sensation. The release of adrenaline causes our skin to contract, which causes the area where hair grows to protrude, making individual hairs stick up, according to Scientific American. So, those little goosebumps are just one more way your body says, “Heads up! This is an abnormal, scary, or emotional situation.” Of course, not all of these body functions are enjoyable (and some are downright disgusting), but it is nice to know there are good reasons why we developed so many seemingly bizarre traits. Next time you find yourself popping a zit or engaging in a little social vomiting, remind yourself that you’ve got your ancestors and their environments to thank.