GEOG 5 Gillespie Thomas 2012 Fall Week 2 Lecture 4 October 9 2012 Announcements 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 Lecture Theory 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 microscope Made 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 Ancestor Developed characteristics Predators 500 mya Seasquirt Backbone 400 mya Fish Eyes Bigger fish 300 mya Reptile Nails Brains Bigger reptiles 225 mya Early Mammals Hair Glands Dinosaurs These 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 2 mya Homo Here we begin to lose characteristics that are no longer necessary Carnivores 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 ago 2 200 000 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 environment w out competition The Polynesians hunted the birds whilst simultaneously bringing new non native animals 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 wiped out native people who had evolved with no resistance to such illnesses