Paleoanthropology Lecture Notes

Introduction to Paleoanthropology

• Study of immediate human ancestors (homininis)
• Relies on fossils found in specific geographic regions: East and South Africa, East Asia, Middle East

Fossilization Process

• Fossilization is rare; less than 10% of species represented
• 95% of fossils are marine animals
• Taphonomy: study of decomposition processes
  • Arrested by dry, cold, or wet anaerobic environments

Types and Dating of Fossils

• Fossils form under specific conditions: sedimentary rock, volcanic activity
• Relative Dating: Provides a relative age comparison without specific dates
  • Law of Superposition
  • Index fossils reflect changes in paleoenvironments
  • Fluorine and cultural dating provide relative timelines
• Absolute Dating: Offers a range of dates
  • Techniques include dendrochronology, radiocarbon dating (limited to <50,000 years), and chemical dating (e.g., potassium-argon, uranium series)

Archaeological Recovery

• Paleoanthropological context: "To dig is to destroy"
• Involves mapping, recording strata, and measuring spatial distributions

Bipedalism

• Facultative: Occurs occasionally (e.g., some primates)
• Habitual: Main form of locomotion (e.g., humans, birds)
• Hypotheses for Bipedalism
  • Hunting, seed-eating, thermoregulation, patchy forest, male provisioning, and chimpanzee hypotheses

Traits in Fossil Record

• Primitive traits: Shared with common ancestors (e.g., opposable thumbs)
• Derived traits: Specific to certain species (e.g., bipedalism)
• Concepts: convergent evolution, parallel evolution, homologous traits, homoplastic traits

Anatomy of Bipedalism

• Important traits: position of foramen magnum, pelvis shape, arched foot, in-line big toe, limb proportions, musculature

Early Hominins

• Miocene Epoch (23-5 mya): Tropical forests, first biped fossils, human-chimp split
• Notable species: Sahelanthropus tchadensis, Orrorin tugenensis, Ardipithecus kadabba/ramidus

Pliocene Epoch

• Cooler, drier climate, expansion of African grasslands
• Australopithecines (4-1 mya)
  • Differences between "robust" (e.g., Paranthropus) and "gracile" australopithecines
  • Notable species: Australopithecus anamensis, afarensis (Lucy), africanus (Taung Baby), platyops, garhi, sebida

Robust Australopithecines (Paranthropus)

• 3-1 mya, large teeth, sagittal crest, dish-faced
• Species: A. boisei, A. aethiopicus, A. robustus

Pleistocene Epoch

• 2.6 mya - 11,700 ya, cooling period, glaciation

Early Homo

• Homo Habilis (2.5-1.8 mya)
  • Larger cranial capacity, human-like dentition, Oldowan tools, "precision grip"
• Homo Naledi: Long arm/leg ratio, small brain
• Homo Erectus: First to leave Africa, found in Java, associated with Acheulean tools and fire use

Homo Heidelbergensis

• Differentiated from Homo erectus
• Characteristics: increased brain size, more rounded brain case, less angled occipital
• Notable sites: Atapuerca, Kabwe, Dali, Jinniushan

Neanderthals

• Late archaic Homo sapiens, found in Europe and the Middle East
• Larger cranial capacity, robust features, Mousterian tools
• Evidence of culture: burials, symbolic behavior

Homo Denisova

• Discovered in Altai Mountains, distinct from both Homo sapiens and Neanderthals

Homo Florensiensis

• "The Hobbit," found in Flores, Indonesia, small stature

Early Modern Homo Sapiens

• Earliest fossils in Africa (300 kya)
• Unique morphology: high forehead, rounded cranium
• Found in Africa, Middle East, Asia, Europe, Australia

Upper Paleolithic Culture

• Began ~40,000 ya in Europe
• Advanced tool technologies, cave art (e.g., Chauvet Cave)

First Humans in North America

• Arrived ~13,500 ya, theories on migration routes, Clovis technology

Intermixing

• Evidence of Homo sapiens and Neanderthals interbreeding
• Genetic studies: Neanderthal DNA present in modern humans

Summary

• Paleoanthropology provides insights into human evolution through fossils and archaeological evidence
• Different eras and species contribute to understanding the development of modern humans.