How many seconds since the first humans?

Estimating the time since the first humans appeared involves some assumptions about when "first humans" refers to, typically around 200,000 to 300,000 years ago. If we take an average of 250,000 years, that equates to approximately 7.9 billion seconds (using 1 year = 31,536,000 seconds). This is a rough estimate, as the exact timing of early human emergence is still a subject of research and debate.