GEOG 5Gillespie, Thomas2012 FallWeek 2Lecture 4October 9, 2012Announcements- Required readings: Chapters 2 and 7 Outline of Last Lecture I. Discussion of the various different biomes and their characteristics Outline of Today’s Lecture II. History of ‘you’ III. Distribution and conquest of humans Today’s LectureTheory of Evolution: - Species evolve due to changes in genetic material and environment - Natural selection is the mechanism that causes evolution (survival of the fittest)- Evidence: Physical fossils, DNA – Deoxyribonucleic Acid Discovered in 1958 by Watson and Crick after discovery of Rosaland Franklin began this research when looking at DNA through a microscopeMade up of Adenine - Thymine (AT) and Cytosine – Guanine (CG)Using DNA we can see how similar the species are, for example humans are 99.5% similar to each other, 95% similar to chimps, and are 50% similar to worms! - Ancestor Worship – this is the idea that every single one of our ancestors made it to reproductive age Year Before Present (BP)Common AncestorDeveloped characteristics Predators 500 mya Seasquirt Backbone400 mya Fish Eyes Bigger fish300 mya Reptile Nails, Brains Bigger reptiles 225 mya Early Mammals Hair, Glands DinosaursThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.(shrew)36 mya Primates Thumb, tails, Carnivores2 mya Homo Here we begin to lose characteristics that are no longer necessary.Homo Sapiens evolved 200,000 years ago Current reasons for US Mortality - Heart disease - Cancer - Lung disease- Accidents How humans evolved: (See handout from this lecture) 1. Common Mother and Father: - Mitochondrial DNA – we all had a common mother 200,000 years ago - Y Chromosome – we all had a common father 142,000 years ago2. 200,000 to 10,000 years ago:- Humans were hunter-gatherers- Mega fauna – large mammals which occupied same land as humans (still exists in Africa as they evolved with humans therefore gained characteristics essential to survival)- Competition very effective for survival (in sense of evolution) 3. Evolution in Isolation:- Gigantism – e.g. Moa – a gigantic bird evolved to great size due to isolation - Lose their fear – e.g. Dodo – makes them very vulnerable as they become slow and lose mobility 4. The New World: (12,000 years BP)- Over kill hypothesis: theory by Paul Martin. Explains the extinction of all mega fauna in the New World (and the rest of the earth, e.g. Australia, New Zealand) due to the hunting of invading humans. - Evidence for the over kill hypothesis: Clovis point – bite marks in bone fossils proving that humans were eating the mega fauna 5. Hawaii: - Discovered 1,500 years ago by Polynesians - Birds – evolved from a finch, and adapted to fill all the niches of the environmentw/out competition- The Polynesians hunted the birds, whilst simultaneously bringing new, non-nativeanimals into Hawaii (e.g. rats, pigs, mosquitoes) these new animals and the hunting caused the extinction of indigenous animals- The mosquitoes: were brought over in 1850. These mosquitoes passed malaria from non-native birds to native birds. This caused the native birds to die almost immediately as they had not been exposed to this disease. 6. 2,000 ya – Humans vs. Humans Competition - Diseases were contracted due to the domestication of animals in Europe. E.g. Cattle – Tuberculosis, measles, smallpox, Pigs – Flu Birds – SARS, flu Monkey – H.I.V AIDs - As the Europeans began to colonize new areas (New World) these diseases wipedout native people who had evolved with no resistance to such