Unformatted text preview: Chordate, Vertebrate, and Hominin Diversification I. What synapomorphies define the chordates? Echinoderms Lancelets Tunicates Hagfish Lampreys Sharks, rays, skates Ray-finned fishes Coelacanths Lungfish Frogs & toads Salamanders Mammals Lizards and snakes Turtles Crocodiles (Dinosaurs &) Birds What is the adaptive significance of: the notochord? a muscular tail that extends a muscular tail that extends past the anus? a CNS with a dorsal hollow nerve cord? III. What trends occurred during hominin evolution? Western gorillas, eastern gorillas, chimps, and bonobos knucklewalk, live in African forests, and live in social groups. Chimps and bonobos make and use tools; chimps (and bonobos?) hunt. They also teach their offspring how to do b b ?) h Th l h h i ff i h d things--meaning that they transmit culture. Based on these data, describe the traits of the common ancestor of chimps and humans. Ardipithecus ramidus 4.4 mya 4 4 mya Braincase: 300350cc Ethiopia Females ~1.2m; males ~?m Partly bipedal; partly knucklewalking; treedwelling? Australopithecus afarensis Australopithecus afarensis 3.93.0 mya 3 93 0 mya Braincase: 400500cc Africa Females ~1.1m; males ~1.41.5m Square jaw (apelike) Paranthropus robustus 2.01.0 mya 2 01 0 mya Braincase: 530cc South Africa Females ~1.1m; males ~1.5m Large zygomatic arch Homo (Australopithecus?) habilis Homo (Australopithecus?) habilis 1.91.6 mya 1 91 6 mya Braincase: 650cc Kenya Females ~1.2m; males ~1.3m Stone tools; animal bones with marks indicating butchery Homo erectus 1 70 3 mya Homo erectus 1.70.3 mya
Braincase: 900cc* Africa, Caucasus, Asia ("Peking Man;" "Java Man") Females ?m; males ~1.7m Extensive stone tools; fire? *early specimens; 1100cc late Homo floresiensis Homo floresiensis 0.10.018 mya 0 10 018 mya Braincase: 417cc Flores (Indonesia) Females 1.06m; males ?m Stone tools, fire; hunted dwarf elephants? Nicknamed Hobbits Homo neanderthalensis Homo neanderthalensis 0.30.03 mya 0 30 03 mya Braincase: 1450cc Europe, Middle East, Caucasus Females 1.56m; males ~1.68m Prepared graves; speech? H. heidelbergensis (Africa) a variant? Homo sapiens 0 1myapresent Homo sapiens 0.1myapresent
Braincase: CroMagnon 1350cc (now 1200 cc) Europe, Asia, Africa Currently: Males about 10% taller than females, on average Grave with 2 other adult men, adult woman, infant, animal bones, jewelry, stone tools What trends occurred during human evolution? What trends occurred during human evolution? y ( g ) 1. Body size (height) 2. Male:female size 3. Posture 4. Tooth size 5. Facial features 6. Braincase volume ...
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- Fall '07
- Biology, Homo Sapiens, homo erectus, mya Braincase