Research presented in the chapter contributes to why scientists have taken to nicknaming this time period “the muddle in the middle.” We know that the Middle Pleistocene picks up from Homo erectus and ends with the appearance of anatomically modern Homo sapiens. While the start and the end are clear, it’s the middle that is messy. As more research is conducted and more data is collected, rather than clarifying our understanding of the hominin lineage during this time period, it only inspires more questions, particularly about the relationships between hominins during this time period, including the oft-misunderstood Neanderthal. Research is painting a more detailed picture of Neanderthal intelligence and both biological and behavioral adaptations. At the same time, their relationship to other Middle Pleistocene hominins, including Denisovans, as well as modern humans, remains unclear.
Homonaledi and Homo floresiensis are clear outliers when compared to their contemporary hominin species. Each has surprised paleoanthropologists for both their archaic traits in relatively modern times and their unique combination of traits seen in archaic species and modern humans. While these finds have been exciting, they have also completely upended the assumed trajectory of the human lineage, causing scientists to re-examine assumptions about hominin evolution and what it means to be modern. Add this to the developments being made using ancient DNA, other new fossil discoveries, and other innovations in paleoanthropology, and you see that our understanding of Archaic Homo sapiens and others living during this time period is rapidly developing and changing. This is a true testament to the nature of science and the scientific method.
Clearly, hominins of the Middle Pleistocene are distinct from our species today. Yet, understanding the hominins that directly preceded our species and clarifying the evolutionary relationships between us is important to better understanding our own place in nature.