The origin of modern humans

Where and when did modern humans (Homo sapiens) first appear? Who were our immediate evolutionary ancestors? What features distinguish modern humans and how did these features arise? These questions have gripped the scientific community and the public since the mid-nineteenth century, when the discovery of Neanderthal Man and the publication of Darwin's Origin of Species rocked the foundations of long-held beliefs on the subject. Many new findings, speculations, and reevaluations have sharpened our views of modern human origins since then. Nevertheless, the controversy continues, as the patchy fossil record and new evidence derived from genetic techniques have given rise to competing theories. Are we the result of a single uninterrupted lineage, with each distinct species of human leading directly to the next? Or, do species such as the Neanderthal represent offshoots of an evolutionary tree that died out without leaving successors? Did modern humanity arise roughly contemporaneously in different parts of the world or from a single species in a single location? And how do biological, linguistic, artistic, and technological factors distinguish Homo sapiens from near and distant rela