Chapter 5C •The Evolution of Living Things
Jan 18, 2018
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
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…..
Formation of New Species…..• Speciation – the making of a new species