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….. 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