Nepali Wanderer

In our previous story, we pondered an important question: how did our planet transform from a hostile environment to one with an oxygen-rich atmosphere?

The answer lies in bacteria. Yes, you read that right. So, let’s sit back and enjoy the story of Cyanobacteria, also known as Blue-Green Algae, which made Earth the habitable planet.

But first, let’s think about a simple question. Why do we need oxygen? For that, let’s rewind to some basic science. For a cell to survive, it needs energy. Cells derive this energy from the breakdown of sugar in the presence of oxygen, a process known as respiration. And how do we get sugar? Animals get it from plants, which produce sugar by combining carbon dioxide and water in the presence of sunlight through photosynthesis.

Now that we’re up to date with basic science, let’s travel back millions of years. Oxygen was not present in the Earth’s atmosphere, except for minor amounts in small areas of shallow oceans. Deep in the ocean lay our savior — Cyanobacteria.
These Cyanobacteria were able to perform photosynthesis, converting carbon dioxide and water into oxygen. Bit by bit, or rather Cyanobacteria by Cyanobacteria, they pumped oxygen into our atmosphere. This whole oxidation of Earth’s atmosphere is known as the Great Oxidation Event (GOE). Moreover, these Cyanobacteria didn’t stop there. They evolved into more complex cells and organisms, leading to the world we have today.
To explain this transition, let’s take the route of evolution. Charles Darwin’s theory of Natural Selection posits that members of a species better adapted to their environment are more likely to produce offspring and pass on their traits. Over generations, this leads to major changes in species’ characteristics and even the emergence of new species.

So, to sum up, the miraculously generous Cyanobacteria not only created an oxygen-filled atmosphere but also led to the creation of advanced cells, and later to complex living beings. Natural Selection then led to the development of advanced forms of life on Earth, including humans.

But wait a minute! This is one mistake we humans always make. We tend to think of ourselves as the pinnacle of evolution, viewing everything that came before as a recipe for the final masterpiece. However, that’s not quite the case! We are just another species on Earth, among millions of others, with many species having gone extinct, many still evolving, and many on the verge of extinction. From cyanobacteria to humans and all other species, it has been an adventurous journey of evolution, filled with amazing characters from terror birds to mighty dinosaurs, amidst some massive explosions and extinctions. We humans have been part of this journey for a mere blip in time, perhaps the tiniest of blips.

But we humans are narcissistic by nature and can’t help but put ourselves first. So, let’s just chalk it up to human nature — we are what we are. As for me, I can’t wait to get started on talking about our brief but adventurous stay on Earth.

Next up, we will discuss the origin of humans. (Sorry, dinosaurs, we’re skipping you altogether!)