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