Cyanobacteria: The first seed of space colonization

Making way for a multi-planetary species

Here’s a chart that shows the oxygen levels in the Earth’s atmosphere over the past 4 billion years.

The x-axis shows time in billions of years and the y-axis shows the amount of atmospheric oxygen. The green and red lines give the estimated range. Source: Wikipedia

Notice something weird? There is practically no oxygen in the Earth’s atmosphere until about 2.5 billions years ago. The oxygen levels in the atmosphere increased dramatically after this period. What led to this Great Oxygenation Event?

Cyanobacteria.

Cyanobacteria and their unique history

Cyanobacteria are unicellular bacteria that derive their energy from photosynthesis. They are thought to be the first species to develop the ability to photosynthesize. Generating oxygen as a byproduct of photosynthesis was a game changer that eventually led to the proliferation of multicellular organisms and therefore to animal life on Earth. What’s more, cyanobacteria are the only species to invent photosynthesis in the history of our planet — all plants and algae have derived this ability from them.

A large bloom of cyanobacteria in Lake Atitlán, as seen from space. The lake is in Guatemala, Central America. Source: NASA

Having survived for billions of years and having a wide genetic diversity…