How did humans evolve?

2023-04-14 07:59:00, Kuriozitete sara novak

Illustrative photo

About 6-8 million years ago, deep in the rainforests of Africa, humans shared a distant ancestor with chimpanzees and bonobos. Since then, many things have happened. We came down from the trees, stood on 2 feet, learned to shoot, learned how to start fire, and spread across the globe.

But how did this happen? How does human evolution really work? By the end of the Miocene Epoch—a geological epoch that occurred from 23 to 5.3 million years ago—humans began to diverge as a distinct primate from a common ancestor with other primates.

Today we know that this happened in East and Central Africa in Ethiopia, Chad and Kenya, and we think that our first known ancestor was Sahelanthropus tchadensis. It has also been suggested that this may have been the first species to walk upright over 2 feet.

How did humans evolve?

Like plate tectonics, human evolution allows for big changes, but it takes time. Slight changes in our genetic material occur over a long period of time. They can also occur in the proportion of genes that make up our DNA or in mutations in genes that may occur due to human evolution. Also gene expression, or how genetic changes affect behavior and physical makeup, can drive the evolution of species. The changes in our DNA are small from one generation to the next, but over time they make big changes.

A sporadic mutation, for example, can be passed from generation to generation until it spreads through a family tree.

One of the ways that human evolution occurs is through natural selection, when certain traits that contribute to successful survival are passed on to the next generation. These changes may initially occur as mutations, but the more they occur within a gene cluster, the more common the inheritance of the trait.

Example of evolution in humans

An excellent example is the physical height of man. Homo habilis is an early human species that lived about 2.3 million years ago. He was much shorter, on average 1 meter 22 centimeters. The short stature meant it was too small to survive without living in trees.

This is evident from the thick fingers and long arms, which were used to climb up and down the tree. Over time and with access to bone marrow scavenged from animals, his brain grew, and so did the species. Homo erectus, which lived starting 1.8 million years ago, was about 1 meter 46 centimeters tall, the first species to hunt, and the first to live on land.

It shed its fur to survive the heat of the African savanna and then spread across the globe. Homo erectus also used fire more often, which made it easier to digest meat and allowed more energy for brain growth. It took nearly 1 million years for changes in the chemical molecules we call genes to cause significant changes in the DNA of both species.

Will humans continue to evolve?

After nearly 1 million years, Homo erectus disappeared and gave way to modern humans or Homo sapiens. They were the same physical height as us and also had a similar intelligence. They hunted wild animals with a self-made spear and in groups that allowed them to follow the predators.

Human evolution goes way back in time, before humans were really like that. It started billions of years ago when the Earth itself was evolving. We were built on the DNA of the species that appeared before us on this planet.

Then mutations and changes happened based on this evolution. We humans are still evolving to survive as a species on our ever-changing planet, which we will continue to do as long as humans survive and thrive on Earth./ Adapted from CNA.al