Both dates consequently vary widely from region to region. For example, in European regions, prehistory cannot begin before 1.3 million of years ago, which is when the first signs of human presence have been found; however, Africa and Asia contain sites dated as early as 2.5 and 1.8 million of years ago, respectively. Depending on the date when relevant records become a useful academic resource, its end date also varies. For example, in Egypt it is generally accepted that prehistory ended around 3100 BCE, whereas in New Guinea the end of the prehistoric era is set much more recently, in the 1870s, when the Russian anthropologist Nicholai Miklukho-Maklai spent several years living among native peoples, and described their way of life in a comprehensive treatise. In Europe the relatively well-documented classical cultures of Ancient Greece and Ancient Rome had neighbouring cultures, including the Celts and to a lesser extent the Etruscans, with little or no writing, and historians must decide how much weight to give to the often highly prejudiced accounts of these protohistoric cultures in Greek and Roman literature.
