  Probably first appeared about 200,000 years ago.  Paleoanthropologists study human evolution.  There is sparse evidence relating to the evolution of humans - pieces of a puzzle in time, some out of sequence, with many pieces missing.  DNA, RNA, proteins, and chromosomes are filling in the gaps in our knowledge of the past.  Species with common DNA sequences are more likely to have arisen from a common ancestor.  Humans belong to the order of mammals called primates. Other primates include tree shrews, lemurs, tarsiers, monkeys, and apes. Homo sapiens: “The wise human ”

  Traits of primates:  mostly arboreal (live in the trees)  highly movable fingers and toes  flattened nails  good vision  color vision (to locate ripe fruit)  front-facing eyes & depth perception  reduced snout, decreased sense of smell.  ability to hold body in vertical position Characteristics of Primates

 Anthropoids  Monkeys, apes, and humans  Well developed collar bone, rotating shoulder joints, partially rotating elbow joints (strength and flexibility)  Opposable thumb – a thumb that can be positioned opposite the other fingers – precision grip  Most also have opposable big toe.  Large brain for body size. Types of Primates

  Fossils show brains get bigger over time. Look at cranial capacity (size of brain case).  Humans and apes- gibbons, orangutans, gorillas, and chimpanzees – have a large cranial capacity relative to body size.  Humans and apes have become increasingly capable of sitting, standing, or walking erectly.  Tail bones reduced in apes and humans. Cont’d

  Bipedal – upright walking on two legs.  Pelvic bones – broad with muscular attachments (supports internal organs during walking)  Foot – big toe aligned with other toes – distributes weight evenly  Jaw and teeth – U-shaped jaw with wide spaces between teeth in apes (pull branches through teeth to strip off leaves). Round jaw with smaller and less specialized teeth (more varied diet)  Brain - Cranial capacity (1,400 cm 3 ) larger than other primates. Large forehead (large frontal part of the brain – verbal language. Characteristics of Humans

  million years ago  cat sized  could run on the ground  lived in the trees  social  males had large canine teeth Aegyptopithecus

  mya  ancestors of apes and humans  lived in trees, but walked more than aegytopithecus  many different forms Hominoids

  4 – 19 mya  ancestors of humans only Hominids

  4 mya  bipedal  hunter-gatherer lifestyle  flat skull bases  humanlike teeth  gorilla-sized brains  4-5 feet tall  did not live in the forest Australopithecines

  3.6 mya  “Lucy” (1974, Ethiopia)  less than 1.5 m tall.  380 – 450 cm 3 cranial capacity (1/3 modern) A. afarensis

  2.8 mya  taller and heavier than A. afarensis  430 – 550 cm 3 A. africanus

  1-2 million years old (Africa)  heavier skulls and larger back teeth  450 – 600 cm 3 A. rubustus & A. boisei

  2.5 mya  Possibly the “missing link” (bridge between Australopithecus and Homo )  Ethiopia near younger Homo fossils  Hunted (butchered antelope) A. garhi

  2.3 mya - present  Early species coexisted with Autralopithecus Homo

  1.6 – 2 mya  “handy human”  used tools, butchered animals  600 – 800 cm 3 H. habilis

 .5 – 1.6 mya  “upright human”  Fossils found in Java (south pacific island)  Thick skull, large brow ridges, a low forehead, & a very small chin  700 – 1,250 cm 3  Probably as tall as modern humans  Used stone tools and hunted  Built fires  Signs of social organization  Angled skull that permitted them to make a greater range of sounds.  Widespread (China, Africa, and Asia)  Families of male-female pairs  Male hunted and female nurtured young  Some fossils as recent as 35,000 ya H. erectus

  Neanderthal  150,000 – 28,000 ya  slightly larger brains than humans  prominent brow ridges  gaps between certain teeth  muscular jaws with small chin  large barrel-shaped chests.  5 ft tall  adapted to cold climate of northern Europe  lived in caves and stone shelters  lived at same time as modern humans H. sapiens - (“the wise human”) probably appeared ~200,000 ya.)

  Cro-magnon (modern)  35,000 ya  1,400 cm 3  high forehead, prominent chin, lack of brow ridges  taller than Neanderthals  sophisticated culture H. Sapiens – Cont’d