Lecture note on populations genetics ucc

Lecture note

1. SESSION 2 :TIMELINES ON HUMAN EVOLUTION: PRE-AUSTRALOPITHECINE BIO208: POPULATION GENETICS AND EVOLUTION UNIT 6

2. Pierolapithecus catalaunicus Age: 11.9 mya Fossils found: nearly complete cranium, much of torso, arms and legs, parts of hands Adaptations: small monkey-like hands, wider pelvis than predecessors, expanded rib cage for climbing Location found: Spain Notes: may be common ancestor of chimpanzees and humans in the human evolution timeline; probably walked semi-upright using forelimbs PIEROLAPITHECUS CATALAUNICUS

3. Sahelanthropus tchadensis Age: 6 – 7 mya Fossils found: nearly complete cranium, some fragments lower jaw and teeth Brain size: 350 cc Adaptations: ape-like, including small brain size, hominid features: brow ridges, small canine teeth Location found: Chad, Central Africa Notes: close to common ancestor of chimpanzees and humans in the human evolution timeline; unlikely to be bipedal SAHELANTHROPUS TCHADENSIS

4. Orrorin tugenensis Age: 6 mya Brain size: no cranium found Fossils found: 13 fossils; partial femur, bits of jaw and teeth Adaptations: unknown Location found: Kenya, Africa Notes: some indications of bipedality, but evidence is scanty ORRORIN TUGENENSIS

5. Ardipithecus ramidus Age: 5.8 – 4.4 mya Brain size: approx. 400 cc (chimp-size) Fossils found: 110 specimens, almost complete skeleton Adaptations: canine teeth intermediate between earlier apes and A. afarensis Location found: Ethiopia Notes: bipedal forest dweller, Canines smaller, not pointed ARDIPITHECUS RAMIDUS

6. Ardipithecus kadabba Age: 5.8 – 5.2 mya Brain size: no evidence Fossils found: fragments, mostly teeth Adaptations: smaller canines than apes (a feature of hominids) Location found: Ethiopia ARDIPITHECUS KADABBA

7. Pierolapithecus catalaunicus Age: 11.9 mya Sahelanthropus tchadensis Age: 6 – 7 mya Orrorin tugenensis Age: 6 mya Ardipithecus ramidus Age: 5.8 – 4.4 mya Ardipithecus kadabba Age: 5.8 – 5.2 mya