Researchers at the University of Liège, Belgium have found cyanobacteria fossils from around 1.75 billion years ago that seem to have had the tools to make oxygen.
- They contain thylakoid membranes, structures in which photosynthesis takes place. The find marks the earliest fossil evidence of photosynthesis.
- The discovery of preserved thylakoids in an ancient microfossils, called N. Majensis, of the coasts of Australia, provides direct evidence of a minimum age of around 1.75 billion years for the divergence between cyanobacteria with thylakoids and those without.
- Thylakoids are little pouches located in the chloroplasts of plants. They store chlorophyll, the substance in plants that reacts to sunlight and triggers photosynthesis.
- They are found in ancient, light-sensitive bacteria called cyanobacteria.
- The latter, multiplied in the oceans billions of years ago, and are believed to be responsible for the vast stores of oxygen that are found in the atmosphere and thus, a precursor to life as we know it.
- However it is now believed that thylakoid membranes in cyanobacteria were what made them capable of using sunlight to create energy and release oxygen.
- The first life on Earth didn’t require oxygen to survive. During the planet’s early days, the atmosphere was mostly made of carbon dioxide, methane and water vapor, instead of the nitrogen and oxygen that dominate today.
- The new study was published in the journal Nature.
