What is the estimated timeframe for H. heidelbergensis?

The timeframe for Homo heidelbergensis is generally estimated to range from about 800,000 to 100,000 years ago. This species is significant in the study of human evolution as it is considered a common ancestor to both Neanderthals and modern humans. Evidence from various archaeological and fossil sites supports this dating, which encompasses a critical period in prehistory when H. heidelbergensis exhibited advanced tool use and potentially even early forms of social behavior or communication that would influence subsequent hominin species.

The other timeframes provided in the options do not align with the established scientific consensus regarding H. heidelbergensis. These incorrect options cover either much earlier or later periods when different hominin species, such as earlier forms of Homo or later, more modern humans were present. Therefore, the timeframe of 800,000 to 100,000 years ago is the most accurate representation of the existence of H. heidelbergensis.