Transcript CH # 5C
Chapter 5C • The Evolution of Living Things Change Over Time….. • Adaptation – a change that helps an organism survive and reproduce in its environment • Species….. • A group of organisms that can interbreed and produce fertile offspring • Humans can mate with humans to make more humans • Strawberry poison arrow frogs can mate with other strawberry poison arrow frogs and produce fertile offspring. Not Species….. • Horses mate with donkeys and produce mules….which are NOT fertile • Female horse * Male donkey – MULE • Male horse * Female donkey - HINNY Mule….. Hinny….. Do Species Change Over Time? • Scientists the Earth is over 4.6 billion years old • Scientists believe that many species have died out and many have appeared • The process of gradual change over time is called EVOLUTION Evidence of Evolution….. • Fossils – the trace remains of an organism the lived long ago, most commonly preserved in sedimentary rock • Fossil Record – a historical sequence of life indicated by fossils found in layers of the Earth’s crust • Evolution of the Whale….. Comparing Organisms….. Section Two….. •How Does Evolution Happen ? Charles Darwin….. • 1831 @ 21 years of age • College Graduate • Dad wanted him to be a doctor • Earned a degree in theology • Interested in plants and animals • 5 year voyage around the world • Served as the naturalist • British ship --- HMS Beagle • His Adventure….. Darwin’s Finches….. Darwin’s Ideas About Breeding • Many farmers grew plants and animals with desired traits • TRAIT – a characteristic that can be passed from parent to offspring • Selective Breeding – when humans select which plants and animals can reproduce …..Ideas on Population Growth • Spoke with Thomas Malthus • Humans reproduce quickly • Food supplies could not support unlimited population • Limited by starvation, disease, competition, and predation …..Ideas about Earth’s History • Darwin learned from a book Principles of Geology that the Earth was formed over a long period of time. • Long enough for changes to occur Darwin’s Theory of Natural Selection • After 20 years of waiting…….. • Published On the Origin of Species by Means of Natural Selection • Natural Selection – process by which organisms that are better adapted will survive and reproduce more successfully Section 3 • Natural Selection in Action • Changes in Populations • Adapting to Hunting • 1% of Males born with w/out tusks • NOW……15% of Males born w/out tusks Insecticide Resistance….. Competition for Mates….. Formation of New Species….. • Speciation – the making of a new species