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Evolution Lec 11 11Feb02 http://life.uiuc.edu/animalbiology/105/ ID: eee105 Password: prAIRie The Depth of Evolutionary Time Oldest fossils: ~3.7 billion years ago microbial microfossils Making the history of life proportionate to one year, each day is 10 million years long The Year of Life Earth’s origin was Oct 15 of the previous year Life begins, Jan 1, 12 midnight prokaryotes The Year of Life Earth’s origin was Oct 15 of the previous year Life begins, Jan 1, 12 midnight prokaryotes The Year of Life Life begins, Jan 1, 12 midnight prokaryotes When do our kind of species evolve? Atmosphere goes aerobic on June 19 2 billion years ago Photosynthetic prokaryotes did it The Year of Life Aug 18 1st Eukaryotes 1.4 billion years ago Oct 23 1st Animals 700 million years ago Nov 2 Start fossil record 600 MYA Nov 10 1st Vertebrates a jawless fish an ostracoderm The Year of Life 27 Nov 1st amphibians The Year of Life 27 Nov 1st amphibians 4 Dec 1st reptiles The Year of Life 27 Nov 1st amphibians 4 Dec 1st reptiles 8 Dec - 23 Dec Age of dinosaurs 150 million years ! The Year of Life 27 Nov 1st amphibians 4 Dec 1st reptiles 8 Dec - 23 Dec Age of dinosaurs 150 million years ! 150 million years is a success story The Year of Life the first Dec 14 mammals Dec 16 birds The Year of Life the first Dec 14 mammals Dec 16 Dec 22 birds flowering plants The Year of Life the first Dec 14 mammals Dec 16 Dec 22 birds flowering plants Dec 23 primates The Year of Life the first Dec 14 mammals Dec 16 Dec 22 birds flowering plants Dec 23 primates The Year of Life When humans? Dec 31 ~2 pm first hominids Dec 31 11:45 pm Neanderthals The Year of Life Dec 31 ~2 pm first hominids Dec 31 11:45 pm Neanderthals Dec 31 11:54 pm Homo sapiens Dec 31 11:58 pm last ice age Last 70 seconds Human history Natural selection How evolve adaptations ? Darwin on the Galapagos Galapagos Islands Galapagos Islands “transmutation” of species Natural selection (1) Individuals vary genetic diversity, always results from sexual reproduction (2) Overproduction of progeny N K biotic potential logistics curve t (2) Overproduction of progeny (2) Overproduction of progeny (2) Overproduction of progeny only a few survive N K biotic potential logistics curve lost t (3) Competition between individuals (4) Fittest individuals survive and reproduce Thus, population becomes better adapted e.g. a population of bacteria N now add antibiotic 0% antibiotic resistance 100% (4) Fittest individuals survive and reproduce Thus, population becomes better adapted e.g. a population of bacteria N now add antibiotic 0% antibiotic resistance 100% (4) Fittest individuals survive and reproduce Thus, population becomes better adapted e.g. a population of bacteria N now add antibiotic 0% antibiotic resistance 100% (4) Fittest individuals survive and reproduce Thus, population becomes better adapted e.g. a population of bacteria N now add antibiotic and they reproduce population is antibiotic resistant 0% antibiotic resistance 100% a routine mutant hunt ….. bacterial colonies on petri plate agar + penicillin a routine mutant hunt ….. penicillin-resistant colony bacterial colonies on petri plate agar + penicillin Antibiotic resistance in disease bacteria