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HumanEvolutionLecture.ppt
- 1. Dr Jeremy Pritchard HumanEvolution: an overview
- 6. o Hominoid: Greatapes and humans o Hominid: Closer to us than gorillas and chimps
- 7. o Humans didnot evolve from Apes o You are descended from your mother and father o You are related to your aunt and cousin Dad Mum Aunt Uncle You Cuz
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- 11. Organisms with common featuresare likely to have a more recent common ancestor.
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- 20. 1. Chimpanzee 2.Australopithecus africanus 3. Homo erectus 4. Homo sapiens
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- 22. Primate Characteristics/Trends o Brainslarger than other animals
- 23. Log body weight(g) Log brain weight (g) • Brains larger than other animals Brains larger than other animals in relation to body size
- 25. • sex • age •stature • race/species • pathological conditions • skeletal trauma Information from the skeleton
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- 33. Sahelanthropus tchadensis • closeto the common ancestor of humans and chimpanzees @ 7 million years
- 35. Australopithecus afarensis Lucy, discoveredin Ethiopia in 1974.
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- 38. Don’t run beforeyou can walk
- 40. Homo habilis (ca.2.5-1.6 mya)
- 42. Homo erectus (1.6mya-300 kya)
- 43. 0 500 1000 1500 2000 0 2 46 8 10 Fossil age (MYA) Brain capacity (cm 3 ) Homo neanderthal Homo erectus Homo sapiens ramapithicus Australopithicus africanus Homo habilis
- 45. Skull radius (cm)Brian volume (cm3) 6 454 6.25 513 6.5 577 6.75 646 7 720 7.25 800 7.5 886 7.75 978 8 1075 8.25 1179 8.5 1290 8.75 1407 9 1531 9.25 1662 9.5 1800 9.75 1946 10 2100 10.25 2261 10.5 2431 10.75 2609 11 2795 11.25 2990 11.5 3194
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- 50. Neanderthals (ca. 100-32kya) o Restricted to Europe, eastern Middle East during Ice Age o Evolved to be cold-adapted: – Short and stocky – Large nose (for warming air) – Barrel chest (for warming air) – Long, low, thick skull but with large Brain
- 51. Neanderthals are notour ancestors Homo sapiens sapiens Archaic Homo sapiens Homo sapiens neandertalensis Homo erectus Homo habilis
- 52. Krings et al1997 Neandertal DNA Sequences and the Origin of Modern Humans NOT our ancestors….
- 53. Are we stillevolving? Microevolution: change in gene frequency - YES Macro evolution : formation of species - NO
- 54. Are we stillevolving? • Some parts of Africa have seen an increase in the frequency of a gene called CCR5-32 • Protects against infection with HIV-1. • May have been selected for during bubonic plague
- 56. 25,000 genes 25,000 genes Human Evolution - Chimps are our closest relative
Editor's Notes
- #27 Jaw = 5 year old child, deciduous teeth erupted, permanent teeth waiting to erupt
- #29 Cut marks on skull – iron age – situated near origin of jaw muscles. – deliberate defleshing or injury in battle?
- #30 Cut marks on skull – iron age – situated near origin of jaw muscles. – deliberate defleshing or injury in battle?
- #31 Cut marks on skull – iron age – situated near origin of jaw muscles. – deliberate defleshing or injury in battle?
- #32 Cut marks on skull – iron age – situated near origin of jaw muscles. – deliberate defleshing or injury in battle?
- #42 H. habilis, "handy man", was so called because of evidence of tools found with its remains. Habilis existed between 2.4 and 1.5 million years ago. It is very similar to australopithecines in many ways. The face is still primitive, but it projects less than in A. africanus. The back teeth are smaller, but still considerably larger than in modern humans. The average brain size, at 650 cc, is considerably larger than in australopithecines. Brain size varies between 500 and 800 cc, overlapping the australopithecines at the low end and H. erectus at the high end. The brain shape is also more humanlike. The bulge of Broca's area, essential for speech, is visible in one habilis brain cast, and indicates it was possibly capable of rudimentary speech. Habilis is thought to have been about 127 cm (5'0") tall, and about 45 kg (100 lb) in weight, although females may have been smaller. Habilis has been a controversial species. Originally, some scientists did not accept its validity, believing that all habilis specimens should be assigned to either the australopithecines or Homo erectus. H. habilis is now fully accepted as a species, but it is widely thought that the 'habilis' specimens have too wide a range of variation for a single species, and that some of the specimens should be placed in one or more other species. One suggested species which is accepted by many scientists is Homo rudolfensis, which would contain fossils such as ER 1470.
- #54 Distributions of Pairwise Sequence Differences among Humans, the Neandertal, and ChimpanzeesX axis, the number of sequence differences; Y axis, the percent of pairwise comparisons