1 / 35

Earliest Hominins

Earliest Hominins. Hominin Phylogeny. Genus Homo. Archaic. Primitive. Mosaic Evolution. Modern human characteristics Appeared at different times Evolved at different rates Extinct hominids show a mosaic of derived and ancestral characteristics. Hominin Evolutionary Sequences.

prentice
Télécharger la présentation

Earliest Hominins

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. Earliest Hominins

  2. Hominin Phylogeny Genus Homo Archaic Primitive

  3. Mosaic Evolution • Modern human characteristics • Appeared at different times • Evolved at different rates • Extinct hominids show a mosaic of derived and ancestral characteristics

  4. Hominin Evolutionary Sequences • Locomotion • Shift from inefficient to more efficient bipedality ca. 2 mya • Dentition • Enamel thickening ca. 4 mya • Gradual reduction of anterior dentition 4.5 mya to present • Gradual reduction of posterior dentition ca. 2.5 mya to present • Encephalization • Limited encephalization from 4 mya to 2.5 mya • Marked encephalization from 2.5 mya to ca. 150 kya

  5. Bipedality

  6. Skeletal Indicators of Bipedality • Pelvis • Distribution of body mass • Relative limb-length • Position of foramen magnum • Lumbar vertebrae • Foot

  7. Primate Taxonomy (DNA-based)

  8. Dentition

  9. Dentition comparison

  10. Early Hominin Molar Size

  11. Primitive Hominins

  12. Sahelanthropustchadensis • Age – estimated to be between 6 and 7 mya • Fossil remains • Nearly complete cranium • Several fragmentary mandibles • Isolated teeth • Cranial capacity – 320-380 cc • Classification uncertain – several possibilities • Position of foramen magnum suggests non-bipedal

  13. Sahelanthropus tchadensis • Chimp-sized brain • Hominin-like brow ridges • Canine wear pattern not ape-like • Thick hominin-like mandible

  14. Orrorin tugenensis • Age ca. 6mya • Fossils remains – mandibles, femur, humerus, large molars, small canines • Femur suggests bipedality • Humerus suggests tree-climbing skills (but not brachiation) • Long bones suggest chimpanzee size • Teeth resemble later hominids

  15. Orrorin tugenensis Femur

  16. Ardipithecusramidus

  17. Archaic Hominins

  18. GRACILE & ROBUST AUSTRALOPITHECINES “Robust” (aethiopicus) “Gracile” (afarensis)

  19. Australopithecus africanus • STS 5

  20. Paranthropus boisei (OH 5)

  21. “gracile” vs “robust” archaic hominins • Au. africanus • P. boisei

  22. Australopithecus ghari • Age ca. 2.5 mya • Later Australopithecine • Limbs suggest bipedality • Incipient megadontia • Found with stone tools and butchered animal remains

  23. Australopithecus ghari

  24. The Genus Homo

  25. Homo [?] habilis

  26. Cranial Comparisons

  27. DmanisiHomo erectus

  28. Homo ergasterKNM-ER 3733

  29. Comparison of Later Forms of Homo

More Related