“Change is the only constant” as the famous saying goes. This comes with the words like evolution and adaptation. Catch words that also bring fear of extinction, the end of old and rustic.
This is the recurring theme in our own history and prehistory, especially with us coming out as a result of millions of years of adaptation from our animal ancestors amidst changing climates and landscapes.
The Theory of Evolution
When it comes to the origin of our species, the Theory of Evolution by Natural Selection of Charles Darwin defines the narrative. A theory formulated or at least organized about 200 years ago. It gave a scientifically back explanation ending centuries of religious dogma and superstition on our beginnings.
According to Darwin's theory, organisms who adapted and learned new skills survived and thrived, while those who failed perished. The survivors then passed their traits to their offsprings until it became natural. Hence the survival of the fittest. Somesort of a game where after completing a level and acquiring new information, you move up to the next.
The same goes to humanity or scientifically called Homo Sapiens. We came out as a result of millions of generations of tribulation. With the correct response to these challenges, our ancestors evolved.
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| Charles Darwin, 1868 |
From Apes to Humans
In the course of millions of years, the planet gradually altered and its inhabitants needed to constantly adapt leading to these physical changes.
The first step in the evolution to humans traced back to 5.3 MILLION YEARS AGO at a time known as the Pliocene Era. An era defined by the reshaping of earth's surface. This led to changes in terrain that also affected the climate.
Back then the Earth's map looked different. The Indian Ocean separated from Asia as did North and South America. Finally, a warmer climate, around 2 - 3 degrees Celsius, prevailed yet forest covered most of the land.
In this environment, our prehistoric ancestors the apes or chimpanzees lived. They sought habitat high up in the trees, away from the threats of large and deadly predators.
For millions of years they stayed up in trees, but their surroundings began to differ. The temperature of the planet began to drop. Forestlands began to shrink giving way to savannahs and grasslands.
Movements in our ground brought upon these changes. The Indian Subcontinent smashed into Asia forming the Himalayan Mountain Ranges while in the west, North and South America collided creating Panama. Alterations in land mass shifted water currents which in turn resulted in climate changes.
Apes then learned to walk in the ground and gathered food. After millions of years, the skills to walk became natural and resulted in physical changes. Thus, the Australopithecines emerged.
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| 19th century artist's impression of a Pliocene landscape |
The Australopithecines
The Australopithecines lived in the regions of Ethiopia, Kenya, and Tanzania. They appeared around 4.4 million years ago up until 1.4 million years ago. They gathered fruits, plants, and nuts with some insects and lizards.
They shared appearances between apes and humans. They have long arms and short legs. Their key difference that made them literally stand out in their walking. They walk in 2 feet or bipedalism in the ground instead of only in trees. A milestone towards the emergence of modern man
The party for the Australopithecines lasted for 4 million years, when mother Earth then again changed geography and climate. In response, they took another step in the ladder towards modern humans.
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| Flint stone tools |
Emergence of Homos
The Pleistocene Epoch ushered in an age of freezing temperatures prompting another round of adaptation. Eventually, the Australopithecines evolved into a new series of Genus to survive, the Homos. Within this genus emerged our species - the Homo Sapiens.
Around 2.6 million years ago, the Earth began to cool down. This marked the beginning of the Pleistocene Epoch, also known as the Great Ice Age. The Northern hemisphere of the planet turned into lands of glaciers and ice sheets. Wind currents from the north going south became cooler and the temperatures began to drop.
Effectively, the hard times fell to the Australopithecus. Scarce Food led to many deaths, but others moved to greener pastures. Another round of adaptation began resulting in a new genus, the Homos, around 2.6 million years ago.
From being bipedal, the Homos developed their minds and hands. Our ancestral Homos observed their surroundings and made stone tools, ate meat, light fires, and talked in languages. Continuous migration and evolutions ran for hundreds of thousands of years.
Around 315,000 years ago, the migration, adaptation, and evolution of earlier homos led to the emergence of Homo Sapiens aka us modern humans. We scattered around the world through land bridges until 12,000 - 10,000 years ago when the Pliocene Epoch came to an end and ushered in the Holocene Epoch.
At the start of the Epoch, glaciers and ice sheets melted. This raised sea levels that sank many land bridges. Homo Sapiens became locked in their respective areas, resulting in various degrees of development depending on the surrounding environment.
From the Ice Age, men furthered their taming of nature, controlling the growth of plants that led to agriculture and the attitude of animals which resulted in domestication of various animals. We began to settle down marking the time as the Neolithic or New Stone Age. Around 6,000 years ago, men finally learned to write leaving us with clues on the life of ancestors. After that, the rest they say is history.
Summing Up
Modern humans have been here for less than 400,000, but change existed for millions of years and there is no stopping it. As the story of evolution from chimpanzees to humans, where we stand today may be different in the next millennium, or hundreds of years.
Making a difference and progress does not happen overnight as well. There is not a day of turning point in our evolution and the same goes to our personal changes. It takes gradual time. Eventually, the changes and skills we study become natural to us and pass over to the next generation onwards.
See also:
Bibliography:
"Australopithecus afarensis." In Smithsonian National Museum of Natural History. Accessed on March 29, 2024. URL: https://humanorigins.si.edu/evidence/human-fossils/species/australopithecus-afarensis
Berggren, W. A. "Cenozoic Era." In Encyclopedia Britannica. Accessed on March 29, 2024. URL: https://www.britannica.com/science/Cenozoic-Era
Johnson, W. Hilton. "Pleistocene Epoch." In Encyclopedia Britannica. Accessed on April 10, 2024. URL: https://www.britannica.com/science/Pleistocene-Epoch
Pontzer, Henry. "Overview of Hominin Evolution." In Nature Education Knowledge Project. Accessed on March 29, 2024. URL: https://www.nature.com/scitable/knowledge/library/overview-of-hominin-evolution-89010983/
Wayman, E. "Becoming Human: The Evolution of Walking Upright." In Smithsonian Magazine. Accessed on March 29, 2024. URL: https://www.smithsonianmag.com/science-nature/becoming-human-the-evolution-of-walking-upright-13837658/#google_vignette
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