Everyone knows that fingerprints are unique to each individual, but no-one quite knows why that is. For many years, scientists believed that we have them in order to improve our grip when grabbing or holding on to something. It turns out that that isn’t the case, because fingerprints actually allow us to grip less. Some of the theories about why we have fingerprints include protecting our fingers, and the provision of touch sensitivity, but the truth is that there is no definitive explanation for them.
Appendixes seem to cause more trouble than they’re worth, with many people suffering pain from theirs and ultimately having to have them removed. Scientists all the way back to the man who came with the theory of evolution, Charles Darwin, all agreed that it was a leftover organ that homo sapiens inherited from a pre-human ancestor, which supposedly needed it to digest its plant-based diet. There is a contending theory, however, that we have appendixes because they house good bacteria, but this has yet to be proven definitively.
3. Dominant hand
Although we accept the fact that we have a dominant hand as something completely normal, but it’s actually quite odd when you think about it. The theory of evolution is all about the “survival of the fittest”, so using that logic, we should have two equally strong hands. There are some people that are very rare exceptions to this rule, but the dominant hand is one of the biggest mysteries about the human body.
No-one quite knows why we yawn. What is known is that we start to yawn in our mother’s womb before we’re even born. There are two competing theories as to why we yawn, namely temperature regulation of the brain, and the notion that we do so to give our bodies a jolt in the event that our heart rate needs to increase. It could be that both are true. Who knows?
5. Blood types
Blood types provide clues to our evolutionary history, however, it’s not clear how or why they evolved in the way that they did. Scientists believe that the start of blood types evolving began some 20 million years ago in our ancestors, as well as other primates. Blood types differ in that they have varying abilities in being able to fight off infections, but no-one knows why different blood types evolved in the first place.
Despite us spending one-third of our entire lives asleep, scientists are at a loss to explain why we dream. What is known is that we dream in REM sleep and that our heart rate increases when we dream. A popular theory about dreaming suggests that it’s our brain’s way of sorting through the memories of the day, allowing it to decide which ones to keep and which ones to get rid of. There are some scientists, however, that believe dreaming is simply the consequence of our unconscious mind being untethered from our awakened state.
There are in fact millions of living things contained in your body. The microbes that live in (and on) us actually account for a few pounds of our body weight, and they have plenty of good reason to be there. They aid digestion, heal cuts and help us battle illness. The thing is that the majority of them are viruses, and no-one has a clue as to what purpose they serve.
8. Contagion of laughter
Powerful emotions can actually cause the brain activity of different people to sync up, as has been discovered by scientists. Human beings are actually 30 times more likely to laugh when in a social situation, and it’s thought that laughter is contagious because we are innately empathetic as a species. Our brains release endorphins when we laugh, and these chemicals help to make us feel safe and at ease.