http://www.physorg.com/ en-us Physorg.com internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine. The mystery of why ancient South American peoples who created the mysterious Nazca Lines also collected human heads as trophies has long puzzled scholars who theorize the heads may have been used in fertility rites, taken from enemies in battle or associated with ancestor veneration. http://www.physorg.com/news150373491.html Other Sciences Mon, 05 Jan 2009 10:24:51 EST news150373491