1 / 21

Human Origins and Evolution

Human Origins and Evolution. Homo sapiens: “ The wise human ”. Probably first appeared about 200,000 years ago . Paleoanthropologists study human evolution .

anne
Download Presentation

Human Origins and Evolution

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Human Origins and Evolution

  2. Homo sapiens: “The wise human” • 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.

  3. Characteristics of Primates • 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

  4. Types 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.

  5. Cont’d • 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.

  6. Characteristics of Humans • 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 cm3) larger than other primates. Large forehead (large frontal part of the brain – verbal language.

  7. Aegyptopithecus • 30 - 40 million years ago • cat sized • could run on the ground • lived in the trees • social • males had large canine teeth

  8. Hominoids • 22-32mya • ancestors of apes and humans • lived in trees, but walked more than aegytopithecus • many different forms

  9. Hominids • 4 – 19 mya • ancestors of humans only

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

  11. A. afarensis • 3.6 mya • “Lucy” (1974, Ethiopia) • less than 1.5 m tall. • 380 – 450 cm3 cranial capacity (1/3 modern)

  12. A. africanus • 2.8 mya • taller and heavier than A. afarensis • 430 – 550 cm3

  13. A. rubustus & A. boisei • 1-2 million years old (Africa) • heavier skulls and larger back teeth • 450 – 600 cm3

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

  15. Homo • 2.3 mya - present • Early species coexisted with Autralopithecus

  16. H. habilis • 1.6 – 2 mya • “handy human” • used tools, butchered animals • 600 – 800 cm3

  17. H. erectus • .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 cm3 • 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

  18. H. sapiens - (“the wise human”) probably appeared ~200,000 ya.) • 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

  19. H. Sapiens – Cont’d • Cro-magnon (modern) • 35,000 ya • 1,400 cm3 • high forehead, prominent chin, lack of brow ridges • taller than Neanderthals • sophisticated culture

More Related