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Unformatted text preview: tion was impossible. Question: When Charles Darwin came into the picture, he had his own view of the Scala Naturae. What do you think it was? Today we have DNA evidence & traditional taxonomic analysis. Draw a phylogenic tree showing the evolutionary relationships among Monotremes Placental mammals Marsupials Reptiles Birds Early Mammallike animal Hadrocodium from China 195 MYA Monotremes This is a story of how science works
An unknown animal is discovered 2) Scientists try to categorize it by comparing it to known organisms. 3) It defies easy categorization. It isn't a mammal--no mammary glands It isn't a bird--no feathers It isn't a reptile--no scales
1) 4. New information: platypus has * mammary glands but no nipples * cloaca reproductive tract like a bird or reptile * lays leathery eggs * shoulder girdle & ear like reptile Conclusion: Platypus is a transitional species between reptiles & mammals 5. Broad conclusions: Platypus is only one example of thousands of transition species not known to ancients & not in Bible & not in the Linnaeus' system of classification. & the millions of extinct species throw Creationism into question Transition species are expected Extinction is expected The transition species Evolution can explain both: Knowledge is always being refined Science is selfcorrecting...
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- Spring '07