Science helped us achieve a lot – like seriously a lot! We have reached Moon and Mars in space. We have discovered/invented vaccines that save millions of lives all over the world.
We achieved quite much as of today, agreed. But can you believe scientists are still scratching their heads on simple things? Don’t you believe us? Scientists don’t really know why we hate to listen to the nail scratching sound on blackboards.
If you feel that this nail scratching thing doesn’t convince you, then read on our list of 10 unsolved biology mysteries.
#10. Why Are Right-handers More in Number Than Left-handers?
You may call us crazy to include this in the unsolved biology mysteries list, but there is no proper answer to the question. Two theories try to explain the cause of this bias (if we can say so).
Some argue that in the evolution process, the speech and language tasks are controlled by the left hemisphere of our brain. The brain’s left hemisphere also controls the right hand. Hence the movements of the right hand were better controlled to produce written language. So, the scientists who support this theory explain that handedness is evolutionary.
The second theory proposes that handedness is genetic. There is a D gene, and then there is the C gene. It is observed in the human population that D gene is more prevalent. D gene promotes right-handedness. C gene is a little different. It allows the person to be either right or left-handed. What does this mean? If you have C gene, then there are 50-50 chances of you being left-handed or right-handed.
Added to these two theories, environmental conditions, society, etc. also play a key role in determining the handedness.
#9. Why Do We Have Fingerprints?
Fingerprints are one of the majorly used methods of identification. Every person in this world has different fingerprints. Twins, triplets, etc. also have different fingerprints.
We have them, but we don’t know the purpose of the fingerprints. Earlier it was believed that fingerprints help us in gripping. But several studies have proved that that is not the case. On the contrary, in some cases having fingerprints reduces contact with objects.
Other theory states that fingerprints help in feeling the texture of the objects. The ridged fingers produce vibrations that are caught by nerves. The nerves then pass on the information to the brain via the neurons.
Another theory suggests that fingerprints’ ridged feature helps in stretching the fingers easily and makes the fingers less vulnerable to injury.
#8. Why Do We Have Different Blood Types?
One of the weirdest unsolved biology mysteries is why do we have different blood groups. We never paid much attention to our blood type differences usually (at least I didn’t). Still, this question plagued biologists and scientists alike.
A person’s blood type is determined by the type of glycoproteins, glycolipids, and proteins present on the RBC (Red Blood Cells). The genes responsible for blood types are inherited.
It is mostly known that Karl Landsteiner discovered A, B, and O blood types, which are original. Since then, we have discovered 23 blood groups with several hundreds of blood types.
Some theories try to explain the reason for different blood types. The environment certainly played a role in creating new blood types. For example, the Duffy blood type allows some malarial parasites to enter RBC. Hence, people from the places where malaria is endemic are Duffy-negative.
In the same way, evolution, like mutation, also was responsible for creating different blood types. Type A is considered to be the oldest (seen in pre-humans). After some mutations in those hominoids, type O was produced.
Another possible theory is that the creation of a new blood type because the present one failed. Let me explain. According to a study published in 2007, type A is not really powerful in handling malaria. Hence, people living in places where malaria is prevalent mostly have B or O blood types.
#7. Why Is Human Sperm Count Declining?
Believe it or not, the count of human sperm is declining since the dawn of the 20th century. What’s worse is that the western part of the world is taking a hit more than the eastern counterpart.
As per the research of Israel’s the Ben-Gurion University of the Negev and the Hebrew University Center of Excellence in Agriculture and Environmental Health, the sperm count was reduced to half in the western world men in the last 40 years. The research was published in 2017, and the study continued from 1973 to 2011.
The decrease in sperm count level is known, but why the level is steadily decreasing is unknown to us to date. Some blame the synthetic estrogen medication given to pregnant women during the 1960s, and others blamed the environmental changes.
Others think that lifestyle changes, stress, drinking, smoking to be the major causes of the decline. The usage of plastic also came under the radar. The chemicals that are used to make plastic hard are pretty similar to estrogen. One more reason to ban plastic, I guess? Needless to say, these all are mere speculations.
#6. What Do the Unknown Proteins Do?
This is one of the many technical unsolved biological mysteries. We know the DNA-blueprints for many proteins, but that doesn’t mean we know everything. A group of researchers from the Luxembourg Centre for Systems Biomedicine studied and found that about 30% of unknown proteins found in yeast and human cells.
You may ask, what is an unknown protein? It is a very valid question. An unknown protein is a protein about which we are ignorant of its functions. In simple terms, when we don’t know the functions of a protein, we call it an unknown protein.
What’s even crazier is that there are no theories as well. There are assumptions for some proteins because of their interaction with other protein complexes. The assumptions are available for some unknown proteins and that too individually.
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#5. Why Do We Age?
Biological aging is called senescence. It is the slow degradation of the body. There are very few organisms that don’t go through senescence. Hydra and some species of starfish can regenerate. Some species of starfish can regenerate or regrow the entire bodies from a single arm.
It is known that every organism dies in this world, but what is unknown is why we age and why we die? The possible reason may be evolution designed us with an expiry date. When we have that expiry date, we tend to focus on reproduction, and our genes can survive in a better way.
Just imagine, if you can live for 300 years. Will you focus on marriage at 40 years? Certainly not. Why? Because you have 260 years more to live! The genes get degenerated as we age, so the children will get weak or improper genes to carry forward.
You may ask, “what about the species that regenerate or regrow?” Natural selection takes care of them if they are no natural predators. Having explained all this, these are all speculations. There is no evidence backing this speculation.
#4. Why Do We Sleep?
Science has certainly advanced to a great extent. Scientists found out the photosynthesis process that takes place in leaves. Thanks to research, we now know answers to many questions, but we don’t know why we sleep! Everyone knows that sleeping is extremely important for organisms to lead a healthy life and even survival. However, scientists are still trying their best to unravel the mystery of why we sleep in the first place.
Many theories try to answer this basic question. One of the main theories states that sleep is simply an energy-saving action of organisms. This theory gets its support from nature herself. Animals who use most of their energy, like Cheetahs, don’t have high chances of survival. However, the theory doesn’t explain how our complex brains may use sleep differently than other organisms.
Another theory believes that while sleeping, the brain flushes out unnecessary information, and neural connections become stronger that are formed during learning. It is this way how long-term memory works. Nonetheless, researches didn’t prove that sleep helps in this particular work process.
#3. Why Do Organs Grow to The Correct Size?
These unsolved biology mysteries are making you question everything, aren’t they? Coming to the question, the research regarding this confuses you more.
In the 1930s, an experiment on salamanders was conducted. The limbs of bigger and smaller species was cut and cross transplanted the limbs to each other. They observed that the cross-transplanted limb didn’t grow in proportion to the body of the animal. The limb grew in proportion to its actual body size.
In the 1960s, the scientists removed the spleen in few mice and replaced the spleens with 6-12 fetal mouse spleens. They observed that 6-12 spleen grew big enough to make an adult spleen of mice.
They repeated the experiment with one difference – the thymus was removed and replaced. To their horror, each thymus developed to be of the size of an adult thymus.
These experiments helped us to understand that both nature and nurture affect the organ size. The cells perceive the environmental conditions and determine how much an organ should grow, or the cells have an autonomous trajectory that it follows.
In other studies, it was observed that cell competition (killing of weak or unneeded cells) is key to decide the organ size. A pathway called the Hippo Signaling Pathway controls the size of the organ.
Even after knowing all these things, the question remains unanswered. How do organs decide the correct size for themselves and stop growing after a period of time? Liver and spleen cells use environmental hints to control the growth, but why thymus goes on an autonomous trajectory? Our scientists haven’t answered these doubts and many more to date.
#2. How the Brain Evolved?
Human brains are the largest (concerning proportion to body size). From about seven million years ago, the human brain has developed and evolved.
The species, Australopithecus afarensis, had similar brain capabilities and capacity (500 ml) to that of other apes of the present day. Later, brain capacity started increasing.
The first species of the Homo genus, Homo habilis, had a significantly bigger brain plus the expansion of the brain’s language part. The evolution of the brain continued for millions of years. The brain capacity of Homo sapiens (ours) is 1,200 or 1,300 ml.
A broad flow chart can be drawn in the brain’s evolution, but how the evolution of the brain was triggered? What led to the triggering of the development? Why it occurred only and only with humans? These are very few questions (of the many) that are yet to be answered.
#1. How Life Originated on Earth?
We know when life appeared on Earth, but what we don’t know to date is how it appeared on our planet. Just like other unsolved biology mysteries, theories trying to explain the phenomenon are abundant, but there is not one single theory that is fully accepted.
Some scientists believe that life didn’t begin on Earth, but life came from some ‘distant world’ or a comet or an asteroid. Some think that there is no one origin of life, but there were many origins of life.
Then there is something called RNA World theory. According to this theory, RNA was the backbone of life before DNA was born. But they fail to explain the origins of RNA.
Another theory states that life started from very basic molecules that are smaller than RNA. The molecules reacted with each other and produced more complex molecules.
As we said earlier, none of the theories are fully accepted. In simple terms, we are still ignorant of how life started on our Earth.
Just in case you are hungry for more such unsolved biology mysteries or any other mysteries, drop in a message, and we will make a new list.