Anthropology 2200 Exam III Study Guide | Complete A+ Guide

Anthropology 2200 Exam III Study Guide You should be able to define, explain, and apply the following concepts: What is a hominin, and how do hominins differ from apes? What is a hominin? – Hominid contains gorilla, ...

Anthropology 2200 Exam III Study Guide You should be able to define, explain, and apply the following concepts: What is a hominin, and how do hominins differ from apes? What is a hominin? – Hominid contains gorilla, chimp, orangutan, and human lineages – Hominin humans and human ancestors How are hominins different from apes? – Appeared earlier  Bipedal locomotion  Non­honing chewing – Appeared later  Significant brain size increase  Complex material culture  Speech Mosaic evolution Mosaic Evolution – Hominin features appeared at different times, not all at once – Consequence?  Early hominins= ancestral and derived traits Dental trends in hominin evolution Enamel thickness – Enamel thickness increases over time, homo sapiens have the thickest enamel Dental arcade General size of teeth Cheat sheet for ancestral vs derived traits that was emailed to you Foramen magnum position (posterior vs. anterior) – Anterior Derived – Posterior Ancestral Shape of the vertebral column (C­shape vs. S­shape) – S­shaped Derived – C­shaped Ancestral Shape of the pelvis (tall and narrow vs. short and broad) – Shorter, broader pelvis Derived – Tall, narrow pelvis Ancestral Femoral neck (short vs. long) – Long Derived – Short Ancestral Angle of the knee (varus vs. valgus) – Valgus Derived – Varus Ancestral Curvature of hand/foot (curved vs. not curved) – Not curved Derived – Curved Ancestral Characteristics of the earliest hominins (Sahelanthropus tchadensis, Orrorin tugenensis, and Ardipithecus ramidus) Sahelanthropus tchadensis – Found in Central Africa, Chad (discovered 2001)  7­6 mya  Lived in forest near a lake Ancestral traits – Face is very ape­like  Prognathic  But less prognathic than an ape – Small brain (~350cc) – Massive brow ridge – Sagittal crest Derived Traits – Foramen magnum=anterior – Non­honing chewing complex – Intermediate enamel thickness Orrorin tugenensis – East Africa: Tugen Hills, Kenya  6mya Locomotion – Long femoral neck (derived) bipedal Derived Characteristics – Non­honing canines – Small teeth with thick enamel (similar to Lucy) Ardipithecus ramidus Ardi’s skeleton – “Ardi” discovered in 1994 – General features  Small brain (300­350cc)  4 feet tall Derived traits Teeth – Non­honing chewing complex – Small, blunt canines – Thicker enamel than apes Anterior foramen magnum – Lumbar curve= s­shaped Limb proportions – Legs and arms about same length (similar to Lucy)  Lost longer ape arms Shorter, broader pelvis – Short and broad compared to chimps  More room for muscle attachments  Easier childbirth – Ardi’s pelvis is taller and narrower than Lucy’s pelvis Ancestral traits Hands – Curved phalanges – Moved on palms of hands and feet while in tree branches Feet – Opposable hallux (big toe) – Also lacks longitudinal arch in foot Ardi’s Arborealism – Ardipithecines palmigrade tree climber & terrestrial biped Main fossil specimens like Ardi, Lucy, and Turkana Boy Ardi Ardi’s skeleton – “Ardi” discovered in 1994 – General features  Small brain (300­350cc)  4 feet tall Ardi’s Arborealism – Ardipithecines palmigrade tree climber & terrestrial biped Lucy Turkana Boy – 1.6 mya  Lake Turkana, Kenya – ~80% of skeleton – Adolescent male (8­11 years old) – 5’3’’ tall – Adult stature would have been ~ 6’5’’ – Cranial capacity=880 cc What is an australopithecine? How do gracile and robust australopithecines differ? Australopithecines No define phylogeny – Difficult to define boundaries of species by morphology  Sexual dimorphism  Australopithecines did not vary much compared to other mammals Australopithecines (“Southern Apes”) – Eastern and Southern Africa – 4­1mya – Bipeds – Small­brained (~400­530