• Human evolution: refers to the evolutionaryprocess leading up to the appearance ofmodern humans.• The study of human evolution involves manyscientific disciplines, including physicalanthropology, primatology, archaeology,linguistics, embryology and genetics.INTRODUCTION
• The species Homo sapiens is about 200,000years old, which is very young, consideringthat life has existed on Earth for at least 3.5billion years.• Derived from early Homonins (Homonids)INTRODUCTION
• Human evolution is characterized by a numberof morphological, developmental,physiological, and behavioural changes .• The most significant of these adaptationsare• 1. bipedalism (1.9 million years ago),• 2. increased brain size,• 3. lengthened ontogeny (gestation andinfancy),• 4. decreased sexual dimorphism.
Characters that distinguish humansfrom other apes:• Upright posture and bipedal locomotion• Larger brains• Language capabilities and symbolicthought• The manufacture and use of complextools• Shortened jaw• Shorter digestive tract
The Earliest Hominins• The study of human origins is known aspalaeoanthropology• Hominins (formerly called hominids) are moreclosely related to humans than tochimpanzees• Paleoanthropologists have discovered fossilsof about 20 species of extinct hominins
• Hominins originated in Africa about 6–7million years ago.• Early hominins had a small brain but probablywalked upright.• Two common misconceptions about earlyhominins:–Thinking of them as chimpanzees–Imagining human evolution as a ladderleading directly to Homo sapiens• We are taking a closer look to the Homininscalled Australopiths and Homo
AUSTRALOPITHS• Australopiths are a paraphyletic assemblageof hominins living between 4 and 2 millionyears ago.• Some species walked fully erect.• “Robust” australopiths had sturdy skulls andpowerful jaws.• “Gracile” australopiths were more slender andhad lighter jaws .• Australopiths got their name from the 1924discovery in South Africa of Australopithicusafricanus (“southern ape of Africa”)
AUSTRALOPITHICUS AFRICANUS• Walked fully upright (Bipedal)• Had humanlike hands and teeth.• Had a brain 1/3 of present humans.Mrs Ples” was an Australopithecusafricanus that lived more than 2-millionyears ago in the Cradle of Humankind
AUSTRALOPITHICUS AFARENSIS• Australopithicus afarensis skeleton was discoveredin Afar (Ethiopia) in 1974.• It was 40% complete, 1m tall and named Lucy.• In 1990 more A. afarensis fossils were discovered.• It showed that they existed as a species for at least1 million years.• Brain size of chimpanzee.• Longer lower jaw.• Arms longer than humans – arboreal movement
EVIDENCE OF TOOL USE• The oldest evidence of tool use, cut marks onanimal bones, is 2.5 million years old• These bones found in Ethiopia.• The marks on bones suggested that Hominins cutflesh from animals using stone tools.• Stone tool use originated before the developmentof large brains.
HOMININS: HOMO• The earliest fossils placed in our genus Homo arethose of Homo habilis, ranging in age from about2.4 to 1.6 million years• Stone tools have been found with H. habilis,giving this species its name, which means “handyman”
• Homo ergaster was the first fully bipedal, large-brained hominid• The species existed between 1.9 and 1.5 millionyears ago• Homo ergaster shows a significant decrease insexual dimorphism (a size difference betweensexes) compared with its ancestors.• Homo ergaster fossils were previously assigned toHomo erectus; most paleoanthropologists nowrecognize these as separate species.• Homo erectus originated in Africa by 1.8 millionyears ago• It was the first hominin to leave Africa
Homo neanderthalensis• Neanderthals, Homo neanderthalensis, lived inEurope and the Near East from 200,000 to28,000 years ago.• They were thick-boned with a larger brain, theyburied their dead, and they made hunting tools.
HOMO SAPIENS• Homo sapiens appeared in Africa by 195,000years ago.• All living humans are descended from theseAfrican ancestors.• The oldest fossils of Homo sapiens outside Africadate back about 115,000 years and are from theMiddle East.• In 2004, 18,000 year old fossils were found inIndonesia, and a new small hominin was named:Homo floresiensis
• Rapid expansion of our species may have beenpreceded by changes to the brain that madecognitive innovations possible.• For example, the FOXP2 gene is essential forhuman language, and underwent intense naturalselection during the last 200,000 years• Homo sapiens were the first group to showevidence of symbolic and sophisticated thought.Art, a humanhallmark
SUMMERY OF OUR “ANCESTORS”1. HOMO HABILIS ~ NICKNAME: Handyman LIVED: 2.4 to 1.6 million yearsago HABITAT: Tropical Africa DIET: Omnivorous – nuts, seeds, tubers, fruits,some meat2. HOMO SAPIEN ~ NICKNAME: Human LIVED: 200,000 years ago to presentHABITAT: All DIET: Omnivorous - meat, vegetables, tubers, nuts, pizza,sushi3. HOMO FLORESIENSIS ~ NICKNAME: Hobbit LIVED: 95,000 to 13,000 yearsago HABITAT: Flores, Indonesia (tropical) DIET: Omnivorous - meatincluded pygmy stegodon, giant rat4. HOMO ERECTUS ~ NICKNAME: Erectus LIVED: 1.8 million years to 100,000years ago HABITAT: Tropical to temperate - Africa, Asia, Europe DIET:Omnivorous - meat, tubers, fruits, nuts5. PARANTHROPUS BOISEI ~ NICKNAME: Nutcracker man LIVED: 2.3 to 1.4million years ago HABITAT: Tropical Africa DIET: Omnivorous - nuts, seeds,leaves, tubers, fruits, maybe some meat6. HOMO HEIDELBERGENSIS ~ NICKNAME: Goliath LIVED: 700,000 to300,000 years ago HABITAT: Temperate and tropical, Africa and EuropeDIET: Omnivorous - meat, vegetables, tubers, nuts7. HOMO NEANDERTHALENSIS ~ NICKNAME: Neanderthal LIVED: 250,000to 30,000 years ago HABITAT: Europe and Western Asia DIET: Reliedheavily on meat, such as bison, deer and musk ox