Check out some fun facts about human evolution!

Kusasira Aaron

Mark NamirengoJuly 2, 2021Last Updated: July 2, 2021

1,019 5 minutes read

In this Article

Why do we get goose bumps?

Goosebumps show that we evolved from earlier mammals. But how?

The body hair of all mammals automatically stands up when cold, creating a fluffy layer of warmth. When we’re cold, the muscles around the hair follicles contract – a reflex left over from when our ancestors had long body hair. But since we don’t have much body hair, all we see are the goose bumps on our skin.

Chickens, chimpanzees, and you – what do they have in common?

Studies show that modern humans are genetically similar to a variety of different organisms.

All modern humans are 99.9% similar to one another in the part of the human genome that codes for proteins. In equivalent areas of the genome, we are 98.8% genetically similar to chimpanzees, 75% genetically similar to chickens, and even 60% genetically similar to banana trees! Humans share large portions of our genome with other organisms due to similar basic functions across the animal kingdom.

Grandparents are unique to humans

Do we have a “grandparent gene”?

cientists have found a unique human genetic variation on our chromosome 19. It doesn’t occur in any other primates, or even in the Neanderthal genome. This gene produces proteins that thwart mental decline in elderly individuals. This seems to be one factor in allowing grandparents help nurture their children’s children.

How strong are we?

Not as strong as our ancestors!

The bones of human ancestors were very strong, able to withstand powerful muscular activity. But about 12,000 years ago, people began to develop agriculture and started living in permanent settlements. It was then beneficial to evolve smaller muscles and lighter bones that didn’t require as much energy to grow and maintain.

Humans are handy!

Why do we have fingernails?

Fingernails help apes, monkeys, and other primates scratch things, peel fruit, pick away the outer layers of other edibles, and perform a variety of other tasks with their fingers. Does this sound familiar? That’s because humans are primates, too! We retain this feature because of our connection with our primate relatives.

Humans: the running ape

Why can humans run long distances?

Humans, horses, and some other mammals sweat, while many do not. With little hair, sweat evaporating from our bodies cools us down quickly. This allows us to continue to run while other mammals must stop when their internal body temperature gets dangerously high.

Our big hungry brain!

Your brain makes up about 2% of your weight but uses about 20-25% of your body’s total energy.

Did you know that your brain makes up about 2% of your body weight…but uses about 20-25% of your body’s total energy, just for its basic activity? That’s one hungry brain! No wonder it’s good to eat nutritious foods that offer a lot of energy. The brain of a newborn baby is even more amazing, as it takes up about 60% of the baby’s energy as the brain grows at an astonishing pace.

Our eyes say it!

Why do humans have such large whites of our eyes?

Compared to other primates, humans have huge ‘whites of the eyes’, or sclera. This means that humans can easily read each other’s gaze. In experiments, great ape infants usually follow a gaze only when the experimenter also turns his head. But human infants follow the gaze when the experimenter moves only his eyes. The whites of our eyes may help a lot in communicating with one another.

The early human tool kit

This basic “tool kit” helped our early ancestors survive.

In Ethiopia, archaeologists have found evidence of toolmaking that dates to about 2.6 million years ago! This ancient “tool kit” included stone cores, hammerstones, and sharp flakes. Early humans knew how to use a hammerstone to strike a stone cobble at just the right angle so that sharp flakes flew off the core. These sharp flakes were then used to cut animal hides and butcher meat, while the hammerstone could be used to crack open nuts. Other evidence from Kenya indicates that earlier episodes of tool making may date back to 3.3 million years ago.

The short-haired human!

While other primates are furry, human skin is exposed to the elements.

While other primates are furry, human skin is exposed to the elements. It’s not that we’re ‘naked’ – our hair is just really short over much of our bodies. In the warm places where our ancestors lived, evaporation of sweat from exposed skin was a great benefit in cooling our entire bodies. Our brain runs so ‘hot’, in fact, that sweating and cooling proved vital for evolving our big brain.

The “Nutcracker”

Which of our early ancestors was given this nickname, and why?

In 1959, paleoanthropologist Dr. Mary Leakey discovered a skull of Paranthropus boisei, our close evolutionary cousin who survived for about 1.5 million years. Her husband, Louis Leakey, aptly nicknamed this early human fossil “Nutcracker Man” because of its large teeth and robust jaw. Yet study of wear caused by food on teeth shows that Paranthropus didn’t usually crack hard foods, but more likely relied on tough foods, such as tubers and roots, to survive. This would require powerful chewing and grinding, and big teeth!

What can lice tell us about human evolution?

The genetics of lice indicates when people invented clothing.

Humans have three kinds of lice living on our bodies – lice that inhabit our heads, bodies, and pubic area. Researchers found that the DNA of head and body lice – which actually have special adaptations for living on our clothing – diverged from each other around 190,000 years ago, indicating that humans began making and wearing clothing around this time.

What does gut got to do with it?

What can the size of our bellies tell us about human evolution?

he proportions of our bodies are a product of millions of years of evolution, including our stomachs! Our ancestor Homo erectus evolved a narrower ribcage and pelvis, shorter large intestines, and longer small intestines. This made the early human gut smaller and it decreased the time it took to digest food! The shorter gut allows for more energy to be diverted from the intestines to other important organs of the body, such as the brain.

Why do paleoanthropologists love Lucy?

Lucy, an early human fossil, helps us understand human evolution.

In 1974, paleoanthropologist Dr. Donald Johanson discovered a 3.2 million-year-old skeleton with both ape-like and human-like qualities in the Afar region of Ethiopia. Known scientifically as Australopithecus afarensis, in the Ethiopian language of Amharic she is called “Dinkenesh”, which means “you are beautiful”. In English, we call her “Lucy”. So why do we love Lucy so much? It’s because we see signs of humanity in her, such as a body built for walking upright on two legs, just like us!

Why do we have wisdom teeth?

When our back molars are impacted in our jaw, they don’t seem very wise!

When our back molars are impacted in our jaw, they don’t seem very wise! They’re the last teeth to come into place, and having them was helpful to our early ancestors who ate tough, uncooked foods that wore away their teeth. But with cooking and making food softer, the size of our jaws has diminished, often with room for the last molars to form in the jaw…but – ouch! – not enough room to erupt.

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