The study of evolution is one that scientists and researchers are completing for the previous couple of centuries, with the most important pioneer within the field of evolution being the English scientist Darwin , whose concepts like survival helped form the idea for the idea of evolution as we all know it today.
In simple terms, evolution refers to “the process by which new species or populations of living things develop from pre-existing forms through successive generations”, as defined by Merriam Webster.
The changes characterizing evolution don't occur in any particular individual alone- these changes that are beneficial for one’s survival are passed onto the offspring then on to a whole population.
This article seeks to seem at human evolution especially, and provides a general overview of an equivalent in layman terms.
What is Human Evolution?
Human evolution refers to “the process by which citizenry developed on earth from now-extinct primates” (Tuttle, 2020). The subject of human evolution in of itself is so vast that there's a separate section of scientific study dedicated thereto referred to as Palaeoanthropology.
It is a subsection of anthropology wherein scientists seek to research the origins of our species and human behavior by studying human fossils.
Something that a lot of might not know is that Homo sapiens , i.e citizenry are one among many species that come under the genus Homo , with other species before us including Australopithecus aphaeresis, Homo erectus, and Homo habilis amongst others.
There are an estimated 15 to twenty such species under the category of early humans. The feature that distinguishes hominids (our early ancestors) from other apes is that of the power to steer on two feet, referred to as bipedalism, which developed over 4 million years ago.
Human beings, chimps and gorillas share a standard ancestor with chimps and bonobos being our closest relatives however the chimp-human lineages split around 7 and a half million years ago.
Fossil and genetic evidence both suggest that humans originated in Africa, with all fossils of early humans (lived in between 2-6 million years) having been found there.
There are alternative ways during which researchers have planned out the stages of human evolution.
Stages of evolution are often grouped in several sections therefore there are often four or five or son counting on how they need been arranged. Here we are watching four main stages of evolution, arranged from the earliest species to the foremost recent:
1. Around 4-7 million years ago: Sahelanthropus, Orrorin and Ardipithecus all appeared between this time period, and they are known as proto-hominids since it is debated whether they are our ancestors or not. They may have been bipedal.
2. Around 4 million years ago: The genus Australopithecus, our ancestors who are also bipedal appeared then, found in both East and West Africa.
3. Around 2.7 million years ago: This is marked by the appearance of species classified under Paranthropus, however, it is unsure whether this classifies as a separate genus since amongst paleoanthropologists many classify it as a subsection of the Australopithecus genus.
4. Between 2.5-1.8 million years ago: This stage consists of the appearance of species that all fall under the genus Homo, which as mentioned before consists of us and our immediate ancestor species. Homo habilis, the oldest is characterized by the usage of stone tools and a chimpanzee sized brain.
Homo erectus and Homo ergaster, the following members had double the brain size and were able to control fire and use relatively advanced. Then came along Homo heidelbergensis about 800,000 years ago and finally Homo sapiens appeared approximately 200,000 years ago.
Some of the main traits or features that helped build modern human society – such as culture and symbolic language are ones we acquired 50,000 years ago.
Another angle of approaching it is looking at the four important steps, or rather four important traits that were involved in the making of modern humans. They are:
1. Terrestriality: This refers to the adaptation of living on land (terrestrial).
2. Bipedalism: As has been mentioned above already, this refers to the ability to walk on two feet. This helped tremendously as now hands could be used for other labour, long-distance travelling became easier, lesser sun exposure, etc.
It also resulted in changes to body parts and changes in bodily processes such as gestation.
3. Encephalization: An evolutionary adaptation involving an increase in the size of the brain and complexity. This increased the possibility for social learning and learning of languages.
4. Civilization: A society that is characterized by advanced cultural and social development, and the making of tools is one such example that is regarded as indicative of evolution.
Hypotheses surrounding early human evolution:
There are a few of hypotheses that are formed regarding the evolution of early humans – allow us to check out a number of them.
The savannah hypothesis suggested that hominids became bipedal as they had to adapt to the savannah after being forced out of trees and thus began walking erect using only their feet.
The aridity hypothesis developed this further to state that evolution also occurred thanks to a rise in aridity and expansion of the savannah.
The turnover pulse hypothesis looked into the role that climate and environmental change played and suggested that it led to a better rate of evolution amongst specialist species and the spreading out of generalist species (as they will grow even with environmental changes).
The study of human evolution is one that's ongoing, not simply because evolution is an ongoing process but also because there's still tons that's unknown.
It is still being analyzed and explored regarding both our origins as a species, our ancestors and our recent evolution, with studies coming out often containing new findings.
Written by: Sanjana Chakraborty
Edited by: Gourav Chowdhury
.jpeg)
0 Comments