With other fossils small bodied 130 cm notably

This preview shows page 5 - 6 out of 6 pages.

with other fossils, small bodied (130 cm), notably smaller teeth, intermembral  index of 70 (arm length/leg length x 100) evolving from chimps who had 100,  KNM ER 1813: fossil from 1.9 mya that show 510 cc brain Twiggy: 1.8 mya with brain 590 cc OH 7 mandible: from Olduvai Gorge 1.8 mya more parabolic dental arcade and  smaller teeth LD 350-1 mandible in Afar Depression 2.8 mya oldest fossil with very small  teeth and more modern looking 3 traits that distinguish Homo habilis from the Australopithecus
Image of page 5

Subscribe to view the full document.

1. Increased cranial capacity: H. habilis 500-700 cc 2. Smaller teeth overall and a slightly more parabolic dental arcade 3. More advanced precision grip: have expanded apical tufts (distal phalanges) for  better grip and finger grip, very modern looking feet with developed big toe, fully  adducted hallux (big toe) and modern looking heel bone important muscle  attachment location it gives fully modern double arch system with transverse arch  and longitudinal arch  Homo rudolfensis  (2.3-1.8 mya) KNM ER 1470 skull from 1.8 mya at Koobi Fora with brain 775 cc. 4 traits  distinguishing rudolfensis from habilis: 1. A larger brain 2. Larger cheek teeth 3. Smaller brow ridge 4. Longer, flatter face? Also has reduced post-orbital constriction. Found no post-cranial bones of rudolfensis so  difficult to say if it was different from others but large brain could assume larger body  size. Many think the differences between the largest and smallest early Homo crania are  too great to fall within the variation of a single species. Most place OH 7 as habilis and  1470 for type species of rudolfensis. If true, then two species of Homo lived  sympatrically in East Africa along with sympatric Australopotheucs. If this is the case,  unclear which early Homo gave rise to the later Homo. Because the differences are up for debate, most see habilis and rudolfensis as different so could possibly see as: 1. Separate species and separate lines from an unknown common ancestor 2. Separate species, same line (ancestor descendant): not just simple replacement  evolution more divergent, rudolfensis evolves from habilis and sticks around for a while 3. Same species, different sexes: not very common interpretation, rudolfensis could  just be a male version of habilis and skulls like twiggy are female and it could be  sexual dimorphism. If this is the case, both seen as habilis and it gave rise to  erectus Either way both fossils had clear evidence of that they made and used stone tools. Whther they were the first or only hominins to make stone tools is debatable but this practice  began around 2.5 mya 
Image of page 6
You've reached the end of this preview.
  • Spring '12
  • Sandgathe
  • A. Afarensis

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern