Apes to Man Human Evolution Human evolution is characterized by several types of changes in phenotype: Note: obviously, these aren't the only phenotypic changes characteristic of the human species, but are more noteworthy in regards to human evolution. Changes in brain size & skull shape вЂў вЂў Smaller to larger brain capacity Spinal insertion moves from rear to base of skull Comparative Brain Sizes Hand Shape вЂў Development of more flexible opposable thumb вЂў Allowed advanced tool use Pelvis shape вЂў вЂў Allowed early hominids to stand & walk upright Gave advantage of being able to see around them on the savannah Spine Shape п‚·Changed from "C" shape to "S" shape Jaw Size вЂўJaw has reduced in size, reflecting changes in species diet вЂўSize of teeth have generally decreased, especially canines Hominid changes over time Timeline of human ancestry ~ 14-16 Million Years to (?) - Ramapithecus & Proconsul вЂў Earliest Ape-like ancestor. вЂў Did not walk upright вЂў Similar in size to the chimpanzee, but stockier Genus Australopithecus вЂў ~ 3.5 - 1 million years - Genus Australopithecus вЂў Several Species of this genus including вЂ“ A. afarensis, A.africanus, & A. boeisi вЂў Earliest is Australopithecus afarensis вЂў Very much apelike with an important feature. Was able to walk upright Australopithicenes Australopithicenes Homo Habilis вЂў ~ 2 - 1.5 million years - Homo habilis "handy man". вЂ“Larger than Australopithecus вЂ“Larger brain вЂ“Was first to use stone tools. Homo habilis Homo habilis contd. Homo erectus вЂў ~ 1.5 Million years - ~ 80,000* years . Homo erectus. вЂ“Larger than H. habilis вЂ“Larger brain вЂ“Smaller face вЂ“Was the first to use fire вЂ“Allowed man to "break out" of Africa into Europe & Asia Homo erectus Homo neanderthalis ~130,000 - 30,000 years. Homo neanderthalis "Neanderthal man" вЂ“ Probably not a direct ancestor - but another offshoot from H. erectus вЂ“ Shorter, stockier, stronger than modern man. Adapted to ice age. вЂ“ Larger brain size than modern man. вЂ“ Buried dead with flowers - first evidence of religeous/symbolic thinking. H. neanderthalis вЂњModernвЂќ man вЂў ~ 100,000 years to present - Homo sapiens (modern man). вЂў Appears to have originated from H. erectus in Africa, then migrated outwards to Europe & Asia. вЂў Replaced existing species H. erectus & H. neanderthalis вЂњRadiationвЂќ theory of H. sapien evolution вЂњParallelвЂќ theory of H. sapien evolution Current phylogeny of H. sapiens How to make a human: вЂў Millions of years ago, a majority of northern Africa was rainforest. Ancestors to man Rapapithecus and Proconsul, were full arboreal apes living in these forests. Changes вЂў However, approx. 5 mya the great rift valley formed in east central Africa. ProblemsвЂ¦.. вЂў The effect of this rift was toвЂ¦ вЂ“ Isolate the ape population from their peers in the west. вЂ“ The rift also created a вЂњrainshadow desertвЂќ to its leeward side. Change of environment. This change in precipitation changed the landscape of the region from rainforest to savannah. The apes needed to develop a new form of transportation since they could no longer brachiate through the trees. Thus, they evolved the ability to walk upright.