In the sequence of appearance of living organisms on Earth:
1. Anaerobic prokaryotes (like bacteria) appeared first. They were able to thrive in the early Earth conditions which lacked oxygen.
2. Cyanobacteria, also known as blue-green algae, came next. These photosynthetic bacteria were able to produce oxygen as a byproduct of photosynthesis, contributing to the rise of oxygen in the atmosphere.
3. Eukaryotic organisms, including protists and simple multicellular organisms, followed. These organisms were able to evolve and adapt to the increasing oxygen levels in the atmosphere.
4. Finally, aerobic organisms like plants, animals, and fungi emerged. These organisms require oxygen for respiration and were able to thrive in the oxygen-rich environment created by earlier organisms.
The organisms that contributed most directly to the rise of aerobic organisms on Earth were cyanobacteria. Their ability to produce oxygen through photosynthesis played a crucial role in increasing oxygen levels in the atmosphere, paving the way for the evolution and success of aerobic organisms that depend on oxygen for survival.
