Over centuries, generations of scientists have tried to come up with an explanation to one of the most fascinating mysteries of all time – The origin of Life on Earth.
It is no secret that ‘Life’ as we know it, is a result of relentless and careful doses of what we call “Evolution”. Evolution is slow, sometimes taking thousands or millions of years, but it is the tool that has shaped life from single celled organisms living underwater, to millions and millions of species alive today, both underwater and on land. Small changes in the DNA of a living organism, may give way to the most exquisite changes in the overall appearance of an organism, or its behaviour, or both. Some of these changes may provide them with a significant advantage over other similar organisms. These organisms then have better chances of survival, and over time, increase in number. This is what’s known as “Natural Selection” – A process where nature selects the species that has a better chance at survival. That species of organisms live on and flourish, while the others may fade away.
However, the biggest question that still remains a brain twister for the greatest of scientists, is Where did the first living organism(s) appear from?
There are a wide range of theories and beliefs surrounding this question.
Some believe life to have been present since the very beginning of our universe, or what we believe to be the beginning of the universe – The Big Bang – which happened approximately 14 billion years ago. While there is healthy skepticism among many regarding the validity of ‘Big Bang’ being the start of the universe, or if the ‘Big Bang’ ever happened for that matter, most agree on it being the initiation and on several occasions, scientists have found substantial evidence that point towards a super-explosion of such grand intensity to have actually happened, most likely being the creator of the observable universe. If life has been there since the beginning, then it is possible that it has since been travelling from one celestial body to another, setting up camp wherever suitable conditions were found. We all agree how sturdy life is; it can survive, learn and evolve even in the most daunting conditions. Still, could life have survived the wild and eventful infancy of the universe? Scientists have discovered organisms that can survive in space, remain frozen for several centuries and still live, and even stay alive in conditions of extreme heat. Is it possible that similar organisms have been part of the universe all along, travelling throughout the universe? Could it be that such similar organisms were part of Earth since the very beginning (4.5 billion years ago), surviving the wild infancy and slowly evolving once the conditions became suitable?
Another theory is that life originated in some other celestial body in the universe, and came to earth with meteors crashing on the Earth’s surface. This theory has been contradicted as well, where some say that the process of entering the earth’s atmosphere from outside is extremely rough, and any organism(s), if present on the meteor, wouldn’t have survived it.
Some also believe that life originated from non-living things, possibly right here on Earth. The base of this theory is that a combination of inorganic matter gave birth to an organic one, under ideal conditions.
Studies have revealed presence of life on earth since at least 3.5 to 3.8 billion years ago, with ‘Stromatolites’ being one of the earliest fossils. This clarifies, that whatever had caused the initiation, it all happened a long time ago, and has been in continuous evolution since then.
There are several other theories on this subject as well, with believers on both ends supporting their end of the theory and denying the others. There are also endless possibilities and details that we haven’t talked about here, but then that’s because the possibilities are endless and are ever increasing.
However, the point of the entire discussion is, that today I would love to know your theory on how life came to our miraculous planet, or how life carved this once inhabitable planet into the grand exhibition of beauty and finesse that we live in now. So, how do you think life started?