Final answer:
Scientists have limited knowledge of human evolution due to scarce fossil remains, which are necessary to piece together the prehistoric past. Advances in genetics, like mtDNA analysis and coevolution with lice, have helped fill in knowledge gaps, but challenges in interpretation remain due to the fragmentary evidence.
Step-by-step explanation:
Scientists know very little about human evolution because there are very few fossil remains. Understanding human evolution involves the interdisciplinary efforts of archaeologists, anthropologists, genetic scientists, and others. Through a limited number of archaeological finds and material remnants, experts have pieced together the story of our prehistoric past, a process fraught with extrapolation and educated speculation due to the fragmentary nature of the evidence.
In the case of early hominins, the fossil record is especially sparse, providing only a narrow window into the complexities of our ancestry. Yet, even with these challenges, the study of fossils, along with genetic data such as mitochondrial DNA (mtDNA), has shed light on the common ancestors of all humans, who lived in Africa roughly 200,000 years ago. Paleoanthropologists use these clues to hypothesize about our evolution, while genetic research, including the study of lice genomes, has illuminated aspects of human history, such as when our ancestors became less hairy and began wearing clothes.
Despite these advancements, much remains unknown about human evolution, which makes this field of study highly dynamic and controversial. The discovery of fossilized remains that are intermediate between Homo erectus and modern humans, as well as our understanding of the relationships between early modern humans and other hominins like Neanderthals, continues to evolve with new findings and research approaches.