We are comfortably living on a ball, a ball of mystery. Yes, the Earth is a mystery that has so many facts established but the reason remains a secret. In the quest of undoing several secrets, the hardest to crack has been human existence. Although the world has progressed manifolds, yet we stand with not so concrete answers for many questions we have had. Undoubtedly we make for the best and worst halves of the world, but how did we evolve into what we are today? The search continues. Anyway, we may still be searching for many things, yet what we have known till now is also so much to be transcribed in a single book. Once we sit down unfolding what we have studied, the pages keep flipping like a never-ending novella.
History of Earth
The Earth is assumed to be formed around 4.6 billion years ago. The solar system was known as the Solar Nebula, a cloud of dust and gas. Gravity collapsed it in itself, as the material started to spin, forming the sun in the center of the nebula. This constituted 98% of only gas constituting of Hydrogen and Helium.
The Earth was a result of a product called accretion. Planets emerged 100,000 years after the Sun came in. The gas giants and the ice giants, that is Jupiter, Saturn, Neptune, and Uranus formed first, followed by Mars, Venus, Mercury, and our home planet Earth.
During its initial years, Earth was just land, or say terrestrial, the blue planet we know today was not found then. Later, Mars-sized objects burst into the Earth, partially liquifying the surface of the earth and ejecting molten debris into space.
This molten debris formed a layer around the earth that later coagulated to form the moon. Then Jupiter and Saturn were caught in the streams caused by the residual gases around the Sun. This gave the Earth to cool down from the formation of the Moon. After the Earth cooled down, the water vapors that got trapped due to the ice slamming on the earth just like various meteors and asteroids, condensed and came down as rain. And, Lava kept flowing for 700 million years.
Around 3.5 billion years ago, two super-continents about the size of present-day India were formed. They were attributed as super-continents because they were the only landmasses at that time. There was no oxygen around that time, yet life existed. Lack of oxygen does not mean there were no life forms on the planet.
The liquid was the only way through which life was supported, that’s why water gets the name a universal solvent. Planktons are thus one of the earliest forms of life, which could be found in present-day Antarctica. These could take in nutrients from various resources and just break them down into simpler substances. Later on, some unicellular organisms could absorb infrared light and produce oxygen. This gave rise to photosynthesis.
Photosynthesis gave the ability to generate food for themselves and the prokaryotes transformed into eukaryotes. Sexual reproduction started 1.2 billion years ago, which led to multicellular life. But, the atmosphere of Earth underwent huge changes due to increased photosynthesis. This led to the first-ever mass extinction. Until now, there have been 24 extinctions with 5 of them being most destructive. And, this also led to the first-ever ice age. We are presently in between the inter-glaciation period of the 5th ice age.
The Human Evolution
Evolution is a huge process and it is not a change of a single individual, but of how inheritance and processes of growth change over time.
Human Evolution is one of the longest evolutions, lasting 6 million years. Science says that humans evolved from ape-like ancestors and the human race had numerous similarities to them. Homo sapiens have similar traits like that of African apes, chimpanzees, and gorillas.
It is believed that the first humans evolved in Africa and all fossils of humans who lived happened 2 to 1.8 million years ago with modern humans traveling to all continents. America got populated only around 30,000 years or so ago. The beginnings of the first civilizations took place around 12,000 years ago.
The road to 7 billion
At present, the population stands at 7.796 billion. The population growth is not a linear graph, that is the growth has been highly haphazard. The population growth started some 12,000 years ago. The population then is estimated to be only 4 million which is less than many present-day small-cities. The astonishing part being population was only 0.8% of today’s population five centuries ago.
It was 3 billion in 1960, and we are already at 7 billion 60 years later. The rapid population growth is attributed to several reasons ranging from economical, political, and social factors. Researchers say that a total of 108 billion people have ever entered this planet, which makes the present population 6.5% of the people who ever lived on the planet. The population growth rate reached its peak(2.2%) a long time ago, in the years 1962-1963. Since then the population growth rate has been declining for years, and the world is not getting overpopulated according to the United Nations.
It is estimated by scientists and seismologists that the Earth as a planet can only hold 9 to 10 billion people. Here, the term hold does not mean that the Earth would collapse. But, we as a population and inhabitants of the earth have only land and food and shelter to accommodate a maximum of 10 billion people. And, the world might reach there by 2100.
But, does that mean the world once hitting 10 billion would finish off? No, the population growth would decline from then on owing to different reasons. The reasons being the increased rate of development which is in turn leading the world to a decreased fertility rate. Also, with more and more parents opting to adopt or not planning a child, the population would see a decrease. Scientists opine that this decline would lead to the loop starting all over again.
COVID-19 and The Population
The COVID-19 pandemic was unprecedented. Nobody foresaw that 2020 would bring in so many challenges. COVID-19 has affected everyone and has brought all of us to a standstill. All sectors, industries, and countries have been hit, so is the world population. The current number of people affected by the virus stands at 12.8 million cases with more than 568K deaths as of 12 July. Not only has the humongous number of deaths affected the population but the pandemic has also changed the way people look at lives and ways they plan their life and family. Thus, it is predicted that the world might see different birth patterns in the coming years.
The pandemic has changed people’s perception and the priorities of one’s life. The deaths and the number of cases prove that the world was not prepared enough for any medical emergency at personal and national levels. Thus, this should be seen as a wake-up call and our priorities should also include better healthcare. As we move towards a better-prepared world, let us be the best versions of humans ever born and make changes that last longer.