Wonder how humans evolved from their ancestors? Take this journey of time to find out about human evolution. Here is an overview on the path through which we, Homo sapiens, evolved from our early ancestors.
1.Introduction:
Ever since Darwin published his groundbreaking theory of evolution through natural selection, humans have been attempting to know about and understand the evolutionary past and story of human beings. Several questions remain without an answer, but these questions are mostly about the details. Paleoanthropologists today know in great detail the emergence of a number of traits that we count, at least on the surface, as unique to modern humans.
This ancestor of human beings and our closest living genetic relatives, chimpanzees, lived around 6 to 8 million years ago. It is through the genetic differences that anthropologists estimated how long it would take for such a mutation to generate the genetic differences that we see today, somewhat like a genetic clock.
After that, innumerable lines within the human family tree had their time in the spotlight, while other lines enjoyed offspring who later evolved into species which eventually became modern human beings.
2.What is Human’s Evolution?
Human evolution is the long and complicated journey that modern humans, Homo sapiens, have gone through from earlier, more primitive species of Hominins including the group from which humans and their ancestors come.
The term “Hominins” includes different kinds of species such as those who are our direct descendants and those who meet us at a common ancestor lineage. These hominins roamed the Earth a long time before the dawn of modern man and are the ones who have given us the clues that connect us to the past through a beautifully arranged mosaic of traits.
3.Stages of Human Evolution:
The genus of modern humans is called Homo, and modern humans are called Homo sapiens. From simple unicellular life forms to the evolution of multicellular organisms, vertebrates gave rise to mammals, and among mammals, humans are most closely related to primates like orangutans. The family to which humans belong is called Hominidae, and it split from the Pongidae (apes) family during the Miocene epoch. Dryopethicus was the first man in the stages of evolution, and some people hold that he is the common ancestor of humans and apes.
3.1. Dryopethicus, the First Hominid, called Ancestors of Humans and Apes:
Lived around 11.1 to 12.5 million years ago:
He was the first known human ancestor. Ramapethicus, who was more human-like than Dryopethicus, existed concurrently with him. Dryopethicus lived in regions of Asia and Africa as well as Europe. He was the starting point for the stages of human evolution. The genus Australopethicus came before the genus Homo, following Dryopethicus and Ramapethicus.
3.2. Ardipithecus Ramidus, the Second Hominid to walk on two feet, (Bi-Pedal Hominins):
Lived Between 7 and 4 million Years Ago.
One of the second hominid species to clearly demonstrate bipedalism walking on two legs was Ardipithecus ramidus. Bipedalism is among the most evident adaptations that set humans apart from our near genetic relatives. We are the only primates that habitually walk on two legs as our preferred mode of locomotion, while other primates do so sometimes.
But there is lack of certainty because Bridget Alex, a paleoanthropologist at the Department of Human Evolutionary Biology at Harvard University, addresses them as the first hominins and says that “The second hominins we see appearing 7 million to 4 million years ago, they seem to be walking on two legs, but they are probably short, like 4 feet tall,” agrees Bridget Alex, a paleoanthropologist. (Alex also frequently contributes to Discover.) Anthropologists can determine the physiology of the majority of the period’s fossil remains by examining fragments of the skull or teeth.
3.3. Australopithecus: The First to Use Hunting Tools and Culture:
Lived 4 Million Years Ago
According to Alex, there are some early human fossils from a group of species known as the Australopiths that lived in what are now arid parts of Africa between 4 and 2 million years ago. The earliest indications of material culture were being displayed by early humans at this period, as stones were being fashioned into crude scrapers and knives.
According to a widely accepted theory, this was a savannah-like habitat where our ancestors could hunt during the day and stay safe from other predators that might emerge in the early morning and evening when the temperature was a little lower. Being able to walk on two feet also allowed us to cover more ground with less energy because less of our body was exposed to the sun.
Their nude appearance is another obvious way that humans differ from other apes. Researchers have found a connection between perspiration and the loss of our thick, dark fur.
“We are by far the most perspiring primate. No other mammal has as many sweat glands as we do. Our light hair and this make it easier for perspiration to escape, which cools us off,” explains Alex.
3.4. Homo Erectus: The First Controlled Use of Fire:
2 Million Years Ago:
The ability to migrate outside of Africa, sophisticated tool making abilities, and the controlled use of fire are all attributes of Homo erectus. The first intermittent use of fire is demonstrated by the discolored sediments discovered in Koobi Fora, Kenya. We frequently forget that our ancestors’ decision to begin cooking their food probably had a significant impact on human evolution.
“Without cooked food, women will lose their periods and become unable to reproduce in a natural environment, so the human body is adapted and dependent on cooked food,” Alex says. Modern people must eat cooked food unless they can afford to purchase the oils and supplements they require.
Food is broken down chemically and physically during cooking, which facilitates the digestive system’s ability to absorb energy from it. This probably helped provide a consistent energy source for our developing, metabolically costly brains. If given the choice, even other animals frequently favor eating prepared food than uncooked.
“Then, two million years ago, a species known as Homo erectus appeared; at this time, they were most likely as tall as modern humans. From the neck down, they resemble modern humans despite having considerably smaller brains, she claims. We witness slow advancements in material culture during this period, as tools and technology become more advanced. It is also believed that a significant proportion of H. erectus moved out of Africa.
Although it really occurs quite late in human evolutionary history, early anthropologists believed that our huge brains must have been the first shift. Between Australopiths and Homo erectus, the size of the brain gradually increased. However, after that, it continued to grow until roughly 100,000 years ago, when cranial capacity essentially reached its maximum.
3.5. Interbreeding of Modern Humans: Homo Neanderthalensis
Lived 250,000 Years Ago:
There is evidence that modern humans and Homo Neanderthalensis shared a genetic inheritance, suggesting that they interbred. According to genomic data, Neanderthals and other modern-day endangered species had a low level of genetic diversity. By the time they were engaging with these
other species, Homo sapiens had a larger population, more genetic diversity, and diverse sections of the planet, making the other species more susceptible to competition from another human species, according to Alex.
There would have been at least four distinct human species on Earth 100,000 years ago: Homo Neanderthalensis, Homo sapiens, Homo Floresiensis, and the Denisovans.However, by 40,000 years ago, we, Homo sapiens, were the only species remaining.
Scientists have proposed a variety of theories to explain why we are the only surviving human species on Earth, but the truth is most likely a complicated combination of various circumstances.
Since Neanderthals and Denisovans lived in ice-age Europe and Asia, respectively, their populations were probably tiny since they were surrounded by harsh surroundings, but modern humans were more widely distributed, with a sizable population in Africa. These previous human species probably went extinct as a result of this and competition with Homo sapiens, who probably had technologies like projectile weapons. However, we also know that interbreeding did occur, as evidenced by the DNA of modern humans.
Furthermore, it would be impossible to discuss human evolution without bringing up the evolution of language. In terms of cognition, language at least as it is used by humans is the most obvious distinction between primates and humans.
Although it is evident that other species are capable of communication, humans seem to possess a special ability to learn language, as evidenced by our ability to intuitively comprehend hierarchical linguistic systems and give meaning to abstract sounds. We become the species we are now because of this invention. It has made it possible for information and culture to flourish, two things that have arguably influenced the evolution of contemporary humanity the most.
