chapter 11 april 2, 2012. climate and human evolution global warming and mammal size as temperatures...
TRANSCRIPT
Chapter 11
April 2, 2012
Climate and Human Evolution
• Global Warming and Mammal Size
• As temperatures increased, their body size decreased.
• Temperature-size rule
• Epigenetic changes
• Blue eyes
• Smallpox
Sahelanthropus tchadensis
• “Toumai”
• Known from a single skull, 4 jaw fragments, and a few teeth
• Flooded woodland/grassland with distinct dry season
• 6 to 7 myo
Orrorin tugenensis
• Moved on the ground using all four limbs, but also moved around in trees
• Tropical forest environment
• 6.2 to 5.65 mya
Australopithecines
• Appeared between 4 and 3.8 mya
• Disappeared by 1 mya
• Fossils found only in Africa
• 3.3–5 feet; 66–132 pounds; small brains
• Closer to modern chimps and gorillas than modern humans
• No evidence of tool making or fire use
• Ate nuts and grasses
Australopithecus sediba
• 1.95-1.78 Ma descendant of Australopithecus africanus
• The australopithecine most closely resembling Homo
• South Africa
• It shares a number of traits with Homo erectus
• mosaic evolution
Skeletons currently on display at the National Museum of Natural History: (left to right) Homo erectus, 1 million years old; Australopithecus afarensis, 2.5 million years old; Homo neanderthalensis, 32,000 to 100,000 years old. Researchers are using
ancient remains like these to learn more about the effects climate change may have had on evolution.
Early Homo
• Oldest Homo fossils 2.5 myo and from Olduvai Gorge, east Africa
• Homo habilis (handy man)• Small hominid• Bipedal• Increased brain size• Manufacture and use of specialized tools• Oldowan Tradition
Homo habilis
Homo erectus
Acheulean Tradition
Homo sapiens
• More prominent brow and thicker skull than modern-day humans
• Appeared 400,000 years ago in Europe, Africa, and Asia
• Eve Hypothesis – all modern humans descended from one African Homo sapiens female that lived 200,000 years ago
• Multiregional Model – Homo sapiens evolved from Homo erectus separately at two or more geographic locations
• Most Anthropologists support Out of Africa Model
Homo sapiens neanderthalensis
• Fossils from 130,000 to 35,000 years ago• Europe and Near East• Only hominids that unquestionably did not
evolve in sub-Saharan Africa• Not ancestral to modern humans• Evolved from archaic Homo sapiens• Mousterian Tradition• Fire, clothing, shelter, rituals, music
Homo sapiens sapiens
• Adapted to warm conditons and open countryside
• Human Revolution – 50,000 years ago rapid expansion inside of and out of Africa; creating art and ritual burials