Final answer:
The first organisms to develop on the early Earth were anaerobic prokaryotes, able to live without oxygen in harsh conditions such as high radiation and temperatures. Cyanobacteria appeared later, producing oxygen through photosynthesis and leading to the transformation of the atmosphere and enabling the evolution of aerobic life.
Step-by-step explanation:
The types of organisms that developed first due to the early environment on Earth were prokaryotes, specifically anaerobic organisms. These organisms were able to thrive in the anoxic conditions that characterized the first 2 billion years of Earth's existence. Among the very first forms of prokaryotic life, anaerobic organisms could survive without oxygen, which was virtually nonexistent in the atmosphere at the time.
As Earth evolved, cyanobacteria emerged within one billion years of Earth's formation. Cyanobacteria became critical to the evolutionary pathway as they are phototrophic and capable of photosynthesis, producing oxygen as a by-product. This oxygenation event led to the gradual transformation of Earth's atmosphere, enabling the development of aerobic life forms, which use oxygen for their metabolic processes.
Early Earth's harsh conditions, including strong radiation, volcanic activity, and high temperatures, necessitated that these initial life forms be highly adaptive and resilient. Their existence set the stage for the subsequent evolution of more complex life, including multicellular organisms and the incredible diversity of life forms we see today.