Human Evolution Chapter 17

Primates Order primates includes prosimians, monkeys, apes, and humans Adapted for an arboreal life

Human Evolution Humans and apes have a common ancestor Misconception: Humans evolved from apes The human lineage and ape linage split around 6 million years ago Humans and chimpanzees are the most closely related share around 99% of our DNA

Lemurs, lorises, and pottos Ancestral Tarsiers primate New World monkeys Monkeys Old World monkeys Anthropoids Gibbons Apes Orangutans Gorillas Figure 17.36 Primate phylogeny Chimpanzees Humans Figure 17.36

Human Evolution All primates share one common mammalian ancestor Other primates diverged from the lineage Prosimians lemurs and tarsiers First primates to diverge Anthropoids New World monkeys, Old World monkeys, and hominoids (apes and hominids)

Human Evolution Proconsul Probable link between monkeys and apes (about 15 mya) About the size of a baboon Probably ancestral to dryopithecines All apes arose from about 10 mya Hominids can also trace their lineage to the dryopithecines

Human Evolution Evolution of Hominids To be a hominid a fossil must have anatomy suitable for standing and walking erect (bipedalism) Bipedalism made food gathering easier Believed that hominids appeared approximately 6 million years ago

? Paranthropus boisei Homo neanderthalensis Homo sapiens 0.5 1.0 1.5 ? Paranthropus boisei Homo neanderthalensis Homo sapiens 0.5 1.0 1.5 2.0 2.5 Homo erectus 3.0 Paranthropus robustus Millions of years ago Homo habilis 3.5 Australopithecus africanus 4.0 Figure 17.38 Timeline of human evolution 4.5 5.0 Australopithecus afarensis 5.5 Ardipithecus ramidus 6.0 Figure 17.38

Human Evolution Australopithecines Evolved in Africa 4 million years ago, went extinct about 1 million years ago Australopithecines had a small brain and walked erect No evidence of tool use Some were gracile (slender), others were robust (powerful)

Australopithecus afarensis

Human Evolution Evolution of Early Homo Earliest fossils are about 2 million years old Larger brain than Australopithecines Jaws and teeth resemble humans Evidence of tool use

Human Evolution Evolution of Early Homo Homo habilis- Brain size as large as 772 cc; enlarged speech areas Smaller cheek teeth indicates an omnivorous diet Findings indicate tool use Crude tools made of stone Culture Encompasses behavior and products Hunter and gatherers may have eaten together and shared food

Human Evolution Evolution of Early Homo Homo ergaster and Homo erectus Fossils date between 1.9 and 0.3 million years ago Larger brain than H. hablis Stood erect, gait was similar to humans Evidence of migration from Africa to Asia Tools were advanced compared to compared to H. hablis First to use fire Systematic hunters

Homo ergaster

Human Evolution Evolution of Early Homo Homo floresiensis Evolved from Homo erectus Small in size compared to other hominids Likely co-existed with modern Homo sapiens

Human Evolution Evolution of Modern Humans

Human Evolution Neanderthals Lived between 200,000 and 28,000 years ago Massive brow ridges, protruding nose, jaws, and teeth Low, sloping foreheads Larger brain than H. sapiens, heavily muscled Culturally advanced According to the Out-of Africa hypothesis, Neanderthals were displaced by modern humans

Neanderthals

Human Evolution Cro-Magnons Oldest fossils to be designated H. sapiens sapiens Modern appearance, made compound tools, were the first to hunt with knives and spears Hunted cooperatively May have been the first to have language Culture included art- sculpture and painting

Cro-Magnons