Human evolution is an interesting process, and it actually helps us to understand the living world surrounding us. Today, we can see evolution in action nearly anywhere that we look. In fact, there’s a high probability that you’re evolving at this very minute, or just carrying random DNA mutations that can be passed onto your kids that provide them a better or worse survival chances in this world.
Human evolution is a long process of change in which people originated from the apelike ancestors starting about 5 million years ago. The modern scientific study of the human evolution is referred to as paleoanthropology.
As a branch of anthropology, this discipline searches for the distinct roots of the human physical traits, behavior, and culture. It attempts to provide answers to some crucial questions: What makes us a human being? When and why did we start to walk upright? And how did our brains, art, language, religion, and music develop?
By approaching these essential questions from various directions, using the information learned from some other disciplines like molecular biology, archaeology, paleontology, biology, and sociology, we continue to learn more about our evolutionary origins.
Many cultures throughout the human history have shared their stories, ideas, and myths about how culture and life came into existence. While the present theory of evolution, based on Charles Darwin’s ideas, is widely accepted by many scientists in our time, it’s significant to remember that several earlier ideas were also recognized. Let us now take a look at some interesting facts surrounding evolution.
1. Our Sex Drive Is No Longer Controlled By a Nasal Organ
Early human beings had relatively small brains. Thus, much of their behavior was controlled by instinct. This is still the case among many animals, and that is why instincts like sexual urges were only triggered by the pheromones, chemicals which are detected by the special organ in the nose.
When human beings became more intelligent and controlled their behavior through a deliberate decision, this vomeronasal organ (VNO) became unnecessary. Nonetheless, the researchers estimate that 50-90% of humans still have vestiges of it. The evidence is inconclusive, though, since the VNO may be present upon a single inspection but untraceable upon another.
2. The Embryo Still Has a Tail
Although some other animals utilize their tails for several different purposes, human beings no longer need them. Thus, our tails have mainly disappeared. Nonetheless, we’ve retained a supporting structure in our lowest 2 to 5 vertebrae that are partially conjoined and form a tailbone.
The human embryo usually has a pronounced tail 31-35 days into its development, but it vanishes as other parts of the body grows.
3. Sharing Of Genes
Humans share nearly 31 percent of their genes with the yeast, one living cell which replicates every 90 minutes. They also share about 50 percent of their genes with the banana.
4. Switch from Brown to Blue Eyes
Many people had brown eyes until nearly 10,000 years ago when one genetic mutation from the Black Sea switched the human eyes from brown to blue. About 8 percent of the current population now has blue eyes.
5. Increase in World’s Population
It took about 100,000 years for the world’s population to reach one billion. Nonetheless, it only took about 133 years for that number to double to two billion and 44 years to reach four billion.
6. The Third Eyelid Is Superfluous
In the corner of our eye, near the nose, there’s a tiny pinkish membrane, the common remnant of something which used to cover the eyeball like the curtain. This third eyelid, known as the nictitating membrane, has now reduced to a negligible size in human beings, though it still works in reptiles, fish, birds, amphibians, and some other mammals.
The transparent membrane helps to protect the eyes. For instance, beavers often dive with it drawn, and the woodpeckers engage it in order to protect their eyes from any flying wood chips when they’re pecking at the trees.
Scientists have discovered that the third eyelid grows very fast in humans during early development of embryonic, but stops as the eyeball keeps growing, leaving this membrane unable to cover it.
7. New Diet Generated ‘Blind Gut’
The appendix was developed to break down hard plant matter, aided by huge amounts of the bacteria. Nonetheless, when early human beings substituted plants with meat, it became superfluous. Now it is just a tube near a junction between the large and small intestines which is usually removed since it gets infected.
Some scientists think that the appendix may have a new role to play, though: When antibiotics food poisoning damages intestinal flora or, some of the ‘good’ bacteria can still survive in the appendix and even recolonize the intestines.