Ch. 6 Primate homologies 1 Overview of the primates -Found in - PowerPoint PPT Presentation

Ch. 6 Primate homologies 1

Overview of the primates -Found in tropics/semi-tropics 2

TL;DR Primate shared derived traits -Primates are arboreal = adapted for living in the trees -Flexible limbs and prehensile hands/feet -Generalized dentition -Increased reliance on vision (compared to mammals) -Longer maturation, reliance on flexible, learned social behavior 3

Overview of the primates Primate shared derived traits are grouped into four categories : 1. Limbs and locomotion 2. Diet and dentition 3. Senses and brain 4. Maturity and behavior Rhesus macaque 4

1. Limbs and locomotion -Generalized limb structure -Opposable thumb -Tactile pads and nails 5

2. Diet and dentition -Omnivorous 6

3. Senses and brain -Color vision -Diurnal -Stereoscopic vision - forward-facing eyes 7

3. Senses and brain 8

4. Maturity and behavior -Long gestation period -Delayed maturation -Few offspring Behavior -Greater dependence on learned, flexible behavior -Highly social 9

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Explaining primate adaptations Question: can we reconstruct the environment primates adapted to to explain their defining traits? Arboreal hypothesis: primate traits = adaptations to living in trees Visual-predation hypothesis: primate traits = adaptations to hunting insects in the lower tiers of the rainforests mya. Flowering plant hypothesis: primate traits developed the same time flowering plants (angiosperms) diversified globally. 11

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Summary of key primate points from Ch. 6 *The primate order consists of the ancestral prosimians and the derived anthropoids (which includes humans). *Compared to mammals, primates are identified as having the following shared derived traits: -Larger bodies/brains -Prehensile hands/feet and flexible limbs -Generalized dentition, are omnivorous -Rely on vision, are diurnal -Longer developmental periods -Flexible, learned social behaviors. *These traits arose as adaptations to arborealism (living in the trees). 13