Ask AI: Explain why an atmosphere rich in oxygen was important for the evolution of life.

An atmosphere rich in oxygen was important for the evolution of life because oxygen is essential for most organisms, fueling respiration and energy-producing reactions. In the early days of life on Earth, there was very little oxygen in the atmosphere. Early life forms had to adapt to these low-oxygen levels, developing new metabolic and respiratory systems capable of surviving in anaerobic environments. As oxygen levels began to rise, these new adaptations allowed organisms to take advantage of the new environment and lead to the evolution of more complicated and complex life forms.