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Published byBenjamin Shepherd Modified over 8 years ago
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Defined: Collection of every known fossil Most fossils found in sedimentary rock Age determined by depth –Law of Superposition: new rock forms on top of older rock Evidence Conclusions: –1) Newer fossils are more complex –2) Common ancestors: similarities between ancient & modern life
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Comparing old fossil to modern life shows change Ancient Kelp Modern Kelp
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Radiometric Dating Helps determine age of fossils Isotopes: atoms of the same element with differing neutrons –Ex: 12 C and 14 C 12 C = 6 protons + 6 neutrons 14 C = 6 protons + 8 neutrons When organism dies: 14 C starts to decay Fossil age determined by comparing ratio of 12 C to 14 C Both are Carbon
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(LUCA)prokaryotes Land prokaryotes Unicellulareukaryotes Multicellular plants Fish (first vertebrates) Land plants & fungi Land animals (amphibians) Amniotic egg (reptiles) Dinosaurs extinct Apes 24 Hour Earth Timeline Dinosaurs appear Outside links Link 1 Link 2 Scale: 1 minute = 3 million years
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AKA: Transition Fossils –Archaeopteryx: shares both bird & reptile features –Basilosaurus: shares whale & land mammal features –Tiktaalik: shares fish & amphibian features Evidence Conclusion : Indicates common ancestry Reptile Evidence Teeth Bony tail Bird Evidence Wishbone Features Whale Evidence Long spine Found in dried up oceans Land Evidence Wolf-like teeth Hind legs Fish evidence Scales Fins Found in dried-up oceans Amphibian evidence Eyes on top of head Wrist bones
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Defined: similar body structures with very different functions Different environments lead to adaptations –Ex: The forelimbs of animals Evidence Conclusion : Indicates common ancestry
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Defined: Organs which have lost most or all their original function Vestigial Human Parts: –Gill slits = once used to breath oxygen in water –Yolk sac = once used to nourish developing embryo –Tailbone = once used for balance –Appendix = once used to digest plants –Wisdom teeth = once used to grind plant tissue Evidence Conclusion : Indicates common ancestry
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Human Embryo w/ Vestigial Structures
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Pythons have tiny femurs (leg bone)
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DNA, RNA, proteins compared Genetic code same for most life More related species have more similar biochemistry Evidence Conclusion : Indicates common ancestry
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Different species show similar development patterns Different body plans become noticeable later in development Evidence Conclusion : Indicates common ancestry
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Antibiotics: drugs designed to kill bacteria –Obtained from fungi Antibiotic Resistance: Bacteria are adapting to the use of antibiotics –Misuse of antibiotics speeds up the process –Importance: Bacteria infections are becoming harder to treat –Example of natural selection Fungus Bacteria
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Antibiotic Resistance GoodBad The antibiotics kill the bacteria, so the area around them are clear The antibiotics don’t kill the bacteria, that’s why there is no clear area around them.
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Pesticides –Chemicals designed to kill pests (rodents, insects, etc…) –Pesticides sprayed on crops to kill pests Pesticide Resistance: pests are adapting to the use of pesticides –“Strong” pests survive to reproduce –Importance: Crops are being destroyed by pests
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First life on earth were prokaryotes (bacteria) Changing environments lead to adaptation Much evidence indicates life has common ancestors
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