1 / 33

Homo Erectus: Nariokotome Adolescent Boy Discovery in 1984

In 1984, the bones of an 11 ½-year-old boy were unearthed in Nariokotome, offering insight into Homo erectus. Discover the surprising features, cognitive abilities, and adaptive niche of Homo erectus in a detailed exploration.

carmela
Download Presentation

Homo Erectus: Nariokotome Adolescent Boy Discovery in 1984

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. Chapter 7Homo erectus

  2. Nariokotome • 1984 the bones of an 11 ½ year old boy were found under a tree along a dry stream channel west of Lake Turkana

  3. Nariokotome • Most complete skeleton of an early hominin ever found. • Died 1.6 million years ago • Know that Nariokotome was an adolescent boy due to: • Shape of the pelvis • Eruption pattern of his teeth • Unfused condition of growth plates of his long bones

  4. Surprising characteristics: • Modern in stature • Pronounced areas of muscle attachment on his long bones • Very thin with narrow hips, and long arms & legs for his height

  5. Bergmann’s & Allen’s Laws for Mammalian Body Proportions

  6. Endocranial volume was 880cc., as an adult it would have had a capacity of 910 cc. • EQ of 3.3 vs. 3.1 for Homo habilis • Expanded right frontal and parietal lobes • Expanded left occipital lobes • Lower left frontal lobes, assigned to Broca’s area in modern humans, is larger than the corresponding region of the right. * Language abilities???

  7. Altriciality: The young are born immature and helpless in condition so as to require care for some time • Second Altriciality: Newborns have rapidly developing brains in the 1st year of life

  8. Homo erectus sensu lato • Homoerectus: defined on the basis of Asian fossils • Homoergaster: African fossils • Geographic distribution distinguishes Homo erectus from earlier hominins

  9. Homo erectus sensu lato • Homo erectus sensu lato lived in: • Africa • Southern Europe • South Asia • East Asia • Southeast Asia • After rapid expansion Homo erectus entered a period of relative stasis

  10. Mode 2 Technology • 1.5 million years ago a new technology emerged • Biface • First tools that existed in the minds of their makers as tools

  11. Mode 2 Technology

  12. Other Mode 2 Technology • Mode 2 sites are most often situated in sand or gravel deposited by streams • They are also situated at higher elevations in different geographic settings

  13. Handedness • Right hand preference • Bipedalism allows hands & arms to gesture • Gestures + vocalizations = language

  14. Fire • Homo erectus may have used fire • Warmth • Scaring away predators • Cooking food • Social opportunities • Communal attention

  15. The Homo erectus Adaptive Niche • Grade shift in cognition

  16. The Homo erectus Adaptive Niche • What we know about Homo erectus: • Larger than earlier hominins • Reduced sexual dimorphism • Had a larger brain, absolutely, than earlier Homo & a slightly larger EQ • Had smaller teeth and face • Had a body build adapted for efficient cooling • Lived in a wider variety of habitats • Had dispersed rapidly to many tropical and subtropical regions of the Old World • Made & used tools of much greater complexity

  17. The Homo erectus Adaptive Niche • Reasonable inferences… • Diets contained more high quality foods • Home range of groups were up to 10x larger than those of other apes • The energy budgets of males & females changed • “grandmother’s hypothesis” vs. male provisioned females • Change in life history patterns • Encountered cognitive challenges

  18. The Weed Hypothesis • Homo erectus was adept at invading disrupted environments and new locales • Rapid colonization an essential component of the Homo erectus niche

  19. Homo erectus Cognition • More sophisticated spatial cognition • Mental templates

  20. Selective Advantages • Larger territory and more unpredictable food source • Large scale spatial thinking selection • Social life • Shape and spatial information coordination selection

  21. Bifaces & Sexual Selection • Standardized • None found at butchery sites • Few signs of heavy use • Sites found with hundreds, but little else • Improvements in appearance, but not in usefulness

  22. Developments In Skill • Expansion in areas of the motor cortex • Arm & shoulder anatomy selection

  23. Memory Systems • Procedural memory • Chaîne opératoire more complex manufacturing sequence • Working memory • 2 main subsystems

  24. Language • Symbols + grammar = language • Increased length & complexity of sequential motor action could account for the expansion of the left inferior premotor cortex • Grammar like rules or linguistic instruction needed for creating handaxes???

  25. Memory Systems • Less powerful processor? • Expansion of ST memory system may have allowed the processing of sounds, transmission of more elaborate meanings, and eventually participation in syntactic processes

  26. Memory Systems • The visuospatial sketchpad & central executive performance correlate strongly • in isolation the VSSP would operate in a pre-attentive, implicit fashion

  27. Memory Systems • Increased LT capacity, especially the capacity for procedural memory and expertise

More Related