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If a fossil is found in a rock with 20% of the isotope carbon 14 left in it. How old is the fossil? Speciation – creation of a new species from an old one. Where do species come from? Microevolution vs. Macroevolution Fast Can see it happen in one human life. Slow Can’t see it happen in one human life. antibiotic resistance dinosaurs and humans Antibiotic Resistance There are millions of bacteria in a host. There are many freaks and variations among the population. Each with unique traits. If antibiotics are given to a person for a long time then all or most of the bacteria is killed. If you stop after a short while the variety that can handle the antibiotic for a short time will be the only ones left. Soon you have a person infected with antibiotic resistant bacteria. Can you see how this might be dangerous? Antibiotic Resistance Antibiotic Resistance Antibiotic Resistance Pesticide Resistance: Bed Bugs http://www.youtube.com/watch?v=SQbLY Oh5hA0 Over use of home treatments cause resistance. Some survive due to variations. They reproduce and the population evolves. Major epidemic in New York. HIV Drug Resistance The same process occurs within the HIV virus. The drugs eventually don’t work because the resistant variants are the only ones to survive. They repopulate the host and levels are back up. They are now all resistant. Darwin’s Dangerous Idea Survival of the fittest & HIV part 1 http://www.youtube.com/watch?v=VYnmJ _IIIIw Survival of the fittest & HIV Part 2 http://www.youtube.com/watch?v=g7j8QL3Z 6qg first 2:00 MRSA Article Natural Selection vs. Artificial Selection Natural Selection – nature selects the traits best suited for an environment. Artificial Selection – humans select the traits we like the best. Crops that produce the most yield. Cows that have the best beef. Fruit trees with the biggest fruit. Dogs All dogs are the same species: Canis Lupus Humans have selected the breeds they like the best and kept breeding those traits. Wild Mustard What is a species? A population that can mate to produce a viable offspring. Frogs and Horses – can’t mate Oliver the Humanzee http://www.youtub e.com/watch?v=9 kJF7hRmKE0 What is going on here? What causes the split? The Galapagos Islands & The MS Beagle Darwin traveled to the Galapagos Islands and studied different finches. Each island had a different finch type. Islands with mountains dividing them in half had 2 types of finches. He asked the question why? Speciation So why don’t all organisms look the same if they all evolve? Why doesn’t the arctic wolf and the African dog look the same? They’re both dogs. Different environments! Where do different species come from? Different environments! Geographic Isolation Whenever a physical barrier divides a population evolution can take different paths. OCEANS MOUNTAINS PACIFIC SIDE DESERTS BOUNDARIES – Changes in land forms ATLANTIC SIDE Creating a New Species Two islands. Both have the same birds. (the same beak variations) Creating a New Species Only one island has a drought and only the large beaked finches survive. On the other island tree worms become abundant and only slender beaks survive. Creating a New Species After some time they can no longer mate together. You now have two different species, each on a different island. Evolution of a Species If there is no geographical isolation then the whole species can evolve into a new one. 1 to 2 If there is geographical isolation then the species can split into two different species. Both can be new or only one. 1 to 1 2 Phylogenetic Tree of Horses Shows the evolution of the species. Speciation new species formed. Extinction species go extinct. Speciation and all evolution Rabbit Evolution Fast Forward http://archive.peabody.yale.edu/exhibits/tr eeoflife/film_discovering.html Chimps evolution http://www.pbs.org/wgbh/evolution/library/ 07/3/l_073_03.html Fossil #1 Fossil #2 A B C D A B C d Fossil #1 A B C D Fossil #3 C A B D Fossil #4 Fossil #5 a B C d a B C d Fossil #2 Fossil #3 Fossil #4 A B C D a B C d A B c d Age: Fossil #2 Fossil #1 20 million years ago A B C D A B C d Age: Fossil #1 80 million years ago A B C D