Unformatted text preview: ORD RECORD 2. THEY WILL BE FOUND 1861 31,000 Invertebrate Fossil Species Known 1900 48,000 “ “ “ 1900 1970 193,000 “ “ “ 1970 1985 250,000 “ “ “ Today ????? Lots more Lots 3. PUNCTUATED EQULIBRIUM
Transitional Species don’t last long Transitional Clicker Question Clicker In which environment are fossils most likely to be In formed? formed? 1) Jungle 2) Temperate forests like New York 3) Deserts 3) 4) Ocean sediments 4) 5) Prairies 5) 35 Fossil interpretation Fossil Troubles with fossil interpretation Troubles Evolution of the Horse Increase in size Decrease in the Decrease number of toes number Increase in Increase complexity of the molars molars Originally believed to be a linear path Most fossil lineages are probably branching branching Four
horse species in Africa Whale Phylogeny Whale
Terrestrial Amphibious Aquatic TRENDS IN WHALE EVOLUTION TRENDS Whale Evolution Whale Nostrils Whale End of snout Middle of snout Top of head (Blowhole) Loss of Legs Loss
Ambulocetus 50 mya Basilosaurus 37 mya Sperm Whale Today Basilosaurus leg skeleton Basilosaurus Ambulocetus hears through ears directly Evolution of Whale Ears Whale Basilosaurus vibrations transmitted by vibrations lower jaw to middle ear lower Modern toothed whale Ecolocation-melon directs Ecolocation-melon sounds & lower jaw receives echoes receives Whale Evolution Whale
Old Idea Based on anatomy New Idea Based on DNA...
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