Explore human lineage through time: Comparison of Human and Ape Chromosomes Becoming Human is an interactive documentary experience that tells the story of our origins. Journey through four million years of human evolution with your guide, Donald Johanson.
Lucy is estimated to have lived 3. Cleveland Natural History Museum, photo by Andrew. Around 30, years ago humans were anatomically and behaviorally similar throughout the world. One of the most hotly debated issues in paleoanthropology the study of human origins focuses on the origins of modern humans, Homo sapiens.
However, by 30, years ago this taxonomic diversity vanished and humans everywhere had evolved into the anatomically and behaviorally modern form.
The nature of this transformation is the focus of great deliberation between two schools of thought: Understanding the issue Multiregional theory: The Multiregional Continuity Model15 contends that after Homo erectus left Africa and dispersed into other portions of the Old World, regional populations slowly evolved into modern humans.
This model contains the following components: Critical to this model are the following tenets: Out of Africa theory: The replacement hypothesis suggests that the genes in fully modern humans all came out of Africa.
As these peoples migrated they replaced all other human populations with little or no interbreeding. To understand this controversy, the anatomical, archaeological, and genetic evidence needs to be evaluated.
Anatomical evidence Sometime prior to 1 million years ago early hominids, sometimes referred to as Homo ergaster, exited Africa and dispersed into other parts of the Old World.
Living in disparate geographical areas their morphology became diversified through the processes of genetic drift and natural selection. In Europe and western Asia they evolved into the Neanderthals.
Neanderthals lived in quasi isolation in Europe during a long, relatively cool period that even included glaciations. Neanderthals are distinguished by a unique set of anatomical features, including: This is a classic example of geographic isolation leading to a speciation event.
In contrast, at roughly the same time, in Africa, a body plan essentially like our own had appeared. While these early Homo sapiens were anatomically modern they were not behaviorally modern. It is significant that modern anatomy evolved prior to modern behavior.
These early sapiens were characterized by: Archaeological evidence Very interestingly, while Neanderthals and early Homo sapiens were distinguished from one another by a suite of obvious anatomical features, archaeologically they were very similar.
This was an abrupt and dramatic change in subsistence patterns, tools and symbolic expression. The stunning change in cultural adaptation was not merely a quantitative one, but one that represented a significant departure from all earlier human behavior, reflecting a major qualitative transformation.
The appearance of fully modern behavior apparently occurred in Africa earlier than anywhere else in the Old World, but spread very quickly, due to population movements into other geographical regions. The Upper Paleolithic lifestyle, as it was called, was based essentially on hunting and gathering.
So successful was this cultural adaptation that until roughly 11, years ago, hominids worldwide were subsisting essentially as hunter-gatherers. It was characterized by significant innovation: Precisely how this transformation occurred is not well understood, but it apparently was restricted to Homo sapiens and did not occur in Neanderthals.
Some archaeologists invoke a behavioral explanation for the change. For example, Soffer11 suggests that changes in social relations, such as development of the nuclear family, played a key role in bringing about the transformation.
Klein7, on the other hand, proffers the notion that it was probably a biological change brought about by mutations that played the key role in the emergence of behaviorally modern humans.
His biologically based explanation implies that a major neural reorganization of the brain resulted in a significant enhancement in the manner in which the brain processed information.
This is a difficult hypothesis to test since brains do not fossilize.The author argues that the roles of human resource professionals must be redefined to meet the competitive challenges organizations face today and into the future. Riddle of the Bones Piece together clues about our early ancestors.
Deep Time Explore 4 billion years of life on Earth. Life's Grand Design Are nature's complex forms evidence of "intelligent design?". Explore the evidence for human evolution in this interactive timeline - climate change, species, and milestones in becoming human..
Zoom . Find and compare Human Resource Software. Free, interactive tool to quickly narrow your choices and contact multiple vendors. Human evolution: The process by which human beings developed on Earth from now-extinct primates. The evolution of human intelligence is closely tied to the evolution of the human brain and to the origin of urbanagricultureinitiative.com timeline of human evolution spans approximately 7 million years, from the separation of the genus Pan until the emergence of behavioral modernity by 50, years ago.
The first 3 million years of this timeline concern Sahelanthropus, the following 2 million concern.