Note
Studied by 12 peopleANTH116 Midterm 2 Review
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### Early Hominin Behavior and Ecology
Q: What are some possible functions of the large molars and premolars in Paranthropus, particularly P. boisei?
A: They were adapted for processing tough and hard foods, such as nuts, seeds, and roots. These dental traits may have been most useful for fallback foods—resources crucial when preferred foods were scarce.
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Q: What are stable carbon isotopes, and how do they help in reconstructing diet?
A:
- Carbon isotopes (C¹³ and C¹²) differ in plants depending on photosynthetic pathways:
- C₃ plants (woody plants, temperate grasses) have lower C¹³ levels.
- C₄ plants (tropical grasses, sedges) have higher C¹³ levels.
- Animals reflect the isotopic composition of their diet:
- Grazers (grass-eaters) show strong C₄ signals.
- Browsers (woody plant-eaters) show strong C₃ signals.
- Carnivores reflect the isotope ratios of their prey.
- Soil carbonates indicate past habitat aridity and grassland extent.
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Q: How did hominin diets shift over time based on isotopic evidence?
A: Before ~3 million years ago, hominins had a diet similar to chimpanzees (purely C₃). Afterward, isotopic signals show increasing consumption of C₄ foods, likely due to expanding grasslands and increased hunting of C₄-feeding animals.
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### Meat Eating, Hunting, and Scavenging
Q: What anatomical changes in Homo suggest increased meat consumption?
A:
1. Smaller gut size (indicating a shift to nutrient-dense foods).
2. Larger brain size, requiring more energy.
3. Reduced tooth size (suggesting external food processing).
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Q: How did brain size increase relate to diet changes?
A: Larger brains require more energy, making high-calorie foods (meat, marrow, cooked foods) crucial for supporting brain expansion.
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Q: What factors contributed to increased energy availability for brain growth?
A:
- Tool use for food processing.
- Cooking, which made food more digestible and nutrient-dense.
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Q: What evidence helps distinguish between hunting and scavenging?
A:
1. Cut marks on bones – Early cut marks suggest hunting; late marks suggest scavenging.
2. Skeletal parts processed – Meat-rich bones suggest hunting, marrow-rich bones suggest scavenging.
3. Tooth vs. tool marks – Determining who accessed the carcass first.
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Q: Why is Kanjera important in the hunting vs. scavenging debate?
A: It provides early (~2 Ma) evidence that hominins acquired complete carcasses, supporting the idea of active hunting rather than scavenging.
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### Bipedalism
Q: What is the pelvic tilt mechanism, and why is it important for bipedalism?
A: It helps maintain balance by preventing the unsupported side of the body from dropping during walking, using the gluteal muscles.
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Q: Why is the inward slant of the femur important for bipedalism?
A: It ensures a horizontal knee joint, aligning body weight over the feet for stability. Present in Australopithecus afarensis.
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Q: Did all hominins walk bipedally in the same way?
A: No.
- Australopithecus sediba had a unique gait.
- Homo erectus (Turkana Boy) had a more modern bipedal stride.
- Homo floresiensis had distinct walking patterns.
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Q: What evidence suggests Australopithecus afarensis had climbing abilities?
A:
- Curved fingers and toes.
- Shoulder and limb structures adapted for climbing.
- A mix of arboreal and bipedal traits.
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### Neanderthals
Q: What cranial and dental features distinguish Neanderthals from Homo sapiens?
A:
- Supraorbital torus – Large brow ridges.
- Occipital bun – Bulging back of the skull.
- Retromolar space – Gap behind the last molar.
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Q: What factors likely contributed to Neanderthal extinction?
A:
1. High energy demands in cold climates.
2. Competition with Homo sapiens (better tools, larger social networks).
3. Small, isolated populations.
4. Rapid environmental changes.
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### Tools and Technology
Q: What is the Lomekwian tool industry?
A: The earliest known stone tools (~3.3 Ma), used before Homo.
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Q: What is the Oldowan tool industry?
A: Early stone tools (~2.6 Ma) associated with Homo habilis, used for cutting and pounding.
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Q: What is the Acheulean tool industry?
A: Characterized by handaxes, appearing ~1.7 Ma and associated with Homo erectus.
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Q: What is the Mousterian tool industry?
A: Middle Paleolithic tool industry linked to Neanderthals, featuring prepared-core techniques.
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Q: What is the Levallois technique?
A: A core preparation method allowing for controlled removal of flakes, used by Neanderthals.
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Q: What are blade, bladelet, and microblade tools?
A: Advanced tools associated with modern humans, allowing for finer cutting and crafting.
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Q: What is a burin?
A: A specialized tool used for engraving and carving.
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Q: Which stone tool industry is associated with Homo erectus?
A: Acheulean (handaxes).
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Q: Which stone tool industry is associated with Neanderthals?
A: Mousterian.
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Q: How do Neanderthal and Homo sapiens toolkits differ?
A: Homo sapiens used a broader range of tools, including blades, projectile weapons, and bone tools, emerging ~300,000 years ago.
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### Middle Pleistocene Hominins
Q: Why is Dmanisi important?
A: It provides early (~1.8 Ma) evidence of Homo erectus dispersing out of Africa.
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Q: Why is Atapuerca (Gran Dolina) important?
A: It contains fossils of Homo antecessor, an early hominin possibly ancestral to Neanderthals.
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Q: What is Sima de los Huesos, and why is it significant?
A: A site with fossils of potential Neanderthal ancestors, showing early Neanderthal traits.
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Q: What is Homo floresiensis, and why is it significant?
A: A small-bodied hominin from Flores Island, possibly a case of insular dwarfism.
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Q: Why is Schöningen important?
A: It preserved wooden spears, showing evidence of planned hunting strategies in Homo heidelbergensis.
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