Original sentence: It is thought that humans had established themselves in the Lough Gur area of the county as early as 3000 BC, while megalithic remains found at Duntryleague date back further to 3500 BC
Edited sentence: It is thought that man had established himself in the Lough Gur area of the county as early as 3000 BC, while megalithic remains found at Duntryleague date back further to 3500 BC