The second major event in the evolution of metabolism was most likely which of the following?

Analyze the options provided: The emergence of aerobic respiration requires oxygen and likely occurred later in evolutionary history. The evolution of multicellularity is unrelated to the biochemical processes of metabolism. Anaerobic photosynthesis, which uses light energy to produce organic molecules without oxygen, is a plausible second event. Glycolysis, as mentioned earlier, is the first event, not the second.

Consider the environmental conditions of early Earth: Early Earth had little to no oxygen in its atmosphere, so metabolic processes that did not rely on oxygen, such as anaerobic photosynthesis, would have been advantageous and likely developed before aerobic respiration.