ANTH 1013 1st EditionExam #3 Study Guide Lectures: 16 - 24Hominin Origins- Derived hominoid traits o Larger brain o Loss of tail o Long arms o Broad thorax - Derived human traits o Bipedal o Small canines o Larger brains o Extended time to maturity o Broad dietary niche and tool use - Anagenetic model of human evolution vs. Cladogenetic model of human evolution o Anagenetic model suggests that there was one simple split (this theory is not likely) o Cladogenetic model suggests that our characteristics appeared various different times in several branches (more likely) - Features related to bipedalism o Spine: Curved to distribute weight  Lordotic: Posteriorly facing curves (2 in humans)  Kyphodic: Anteriorly facing curves (1 in humans)  Chimps have a stiff spine with a slightly kyphodic curve.  Valgus knee with a bicondylar angle: Inward kneed (humans) o Foramen magnum orientation and position  Head - Chimp: On back of head - Human: On middle of head o Short broad ilium rotated into the sagittal plane  Pelvis and femur: Center of gravity and changing action of muscles - Chimps: Tall illium, lies in coronal plane. - Humans: Broad & short illium, rotates to saggital plane. o Gluteal muscle actions on the lower extremity (lesser glutes)  Chimps: use it to extend  Humans: use it to stabilize o Divergent vs. nondivergent hallux and arches of the foot  Humans: Weight is distributed throughout arch of foot, do not have a divergent hallux.  Chimps: Weight is distributed throughout the entire foot, they do have adivergent hallux. - Canine honing complex o Honing = sharpening canines o Three teeth: Maxillary canine  Mandibular canine  Sectoral premolar o Chimps hone their canines whereas humans don't. - Dietary niche: Humans eat pretty much everything, they have a thick enamel and tools in order to process their foods. - Extended time to maturity in humans o Life history o Stages (know the ages and events that mark the transitions between phases)  Conception: 267 days  Infancy: Up to weaning (weaning = stop breastfeeding)  Childhood: In humans, parents still provide food for you, social learning and brain development is critical at this stage. Childhood ends when your first molar erupts.  Juvenile: When you are able to sexually reproduce. (period, first ejaculation)  Adolescent: Happens between sexual and physical maturity.  Adult: 100% physical maturity reached.  Senescence (menopause): Ability to sexually reproduce stops. - Lactation Amenorrhea: o Ovulation is suppressed during nursing, this leads to an average 4 year inter birth interval- Describe the original model of human evolution o Big brains: intelligence, diet, tools use (lead to both) small canines & locomotion - "March towards humanity" (this idea not very likely) - Identify some of the earliest fossil discoveries and how they contributed to early thoughts on human evolution o Engis: Discovered in 1829 in Belgium, Neanderthal, was ignored until the 1900's o Gibraltar: Discovered in 1848 in Spain, Neanderthal, was largely ignored o Neanderthal type specimen (Neander Valley): Member of Homo Neanderthalis discovered by Grotto in 1856 and was described a year later. o La Chapelle aux Saints: Discovered in France in 1908, Neanderthal. Was elderly, lost postcanine teeth, arthritic. o Piltdown man:  Had human cranium and an ape mandible  Found by Charles Dawson in Great Britain  Said to be missing link to confirming that human intelligence evolved first.  Scientific name was Eoanthropus Dawsoni (Dawson's Dawn Man) Issues:  Missing link between humans and apes  No face & no articulation  Cranium & mandible were found at different times  3 respected scientists ruled that it was a fraud that had been filed down  Dawson claimed to have found another, then died not long after  Florine testing came out and ruled that the bones were from different times and not from ancient times (1949) o Taung Child  Human like teeth with thick enamel & small canines with a Foramen Magnum below the skull, suggests it was bipedal  Size of cranium suggests that its brain was chimp sized  Opposes Piltdown Man because it says that canine reduction & bipedalism occurs before brain size expansion (which concludes brain size is not the defining feature of Hominins) (its either canines or bipedalism)  Opposite scenario as envisioned by early evolutionary thinkers. this idea was ignored by the Brits  Raymond Dart: Discovered the Taung Child but does not share his fossil Earliest Hominins/Australopithecus and Paranthropus- Be able to identify the major geographical regions associated with early hominin discoverieso Rift Valley o Ethiopia and Afar Triangle o Kenya and Lake turkana o Tanzania o Chad o South Africa - For each fossil hominin, be able to describe the geographic range, temporal range, majormorphological features, important specimens, important localities, and date/discoverer o Sahelanthropus tchadensis  Sahel = sahara  Anthro = human  Tchad = chad  Ensis = originated from  Was discovered in 2004 by Michael Brunet  From Chad  7 million years ago  Important specimens: Toumai  Important localities: Toros Menalla - Morphological features: o Anteriorly placed foramen magnum? o Small canines (no honing) o Large brow Issues: o There is no postcrania to determine bipedalism Conclusion: - Could be oldest evidence of hominins o Orrorin tugenensis  Orrorin = first human in Tugen language.  Tugenensis = Tugen Hills, Kenya  Ensis = originated from  Discovered in 2000 by Martin Pickett and Bridgitte Senut  6 million years ago  Important specimens: Millenium man  Important localities: Tugen Hills, Kenya - Morphological features: o Thick femur o Small canines (no honing) Issues: o There is no distal end of femur shown o Limited sample size o Few teeth o Discoverers argued Conclusion:- Could be oldest human like biped o Ardipithecus kadabba  Ardi = ground  Pithecus = ape  Kadabba = oldest ancestor  Discovered in 2004 by Yohanes Haines Selassie  5.8 - 5.2 million years ago  Important specimens: N/A  Important localities: Middle Awash, Ethiopia - Morphological features: o No skull, but it is associated with the ardipithecus radimus because they are the same genus. o Ardipithecus ramidus  Ardi = ground  Pithecus = ape  Radimus = root  Discovered in 1994 but fully discovered in 2008