Final answer:
The cons of studying hunter-gatherers as a window into pre-history include the lack of knowledge about early social structures and cultural values, as well as the changing nature of gatherer-hunter groups over time.
Step-by-step explanation:
The cons of studying hunter-gatherers as a window into pre-history include the lack of knowledge about early social structures and cultural values, as the archaeological record focuses more on diet and diseases. Contemporary gathering and hunting groups can provide some insight, but they are not frozen in time and have been influenced by other subsistence methods. Additionally, the way of life of gatherer-hunter groups has changed dramatically in the past century, making it difficult to draw firm conclusions about human evolutionary history based on their example.