Chapter 13 Theory of Chapter 13 Theory of EvolutionEvolution

Vocabulary for Ch. 13Vocabulary for Ch. 13

Natural SelectionNatural SelectionVestigial StructureVestigial StructureHomologous StructureHomologous StructurePunctuated EquilibriumPunctuated EquilibriumReproductive Isolation Reproductive Isolation Isolation Isolation Speciation Speciation GradualismGradualism

Charles DarwinCharles Darwin

Proposed a mechanism for Evolution Proposed a mechanism for Evolution that has become widely accepted.that has become widely accepted.

Traveled throughout the world Traveled throughout the world collecting evidence of evolutioncollecting evidence of evolution

Proposed that Natural Selection is Proposed that Natural Selection is driving force in Evolutiondriving force in Evolution

Was influenced by the work of Was influenced by the work of Thomas Malthus (Populations) and Thomas Malthus (Populations) and Charles Lyell (Geology)Charles Lyell (Geology)

Darwin Darwin

Traveled from 1831-1836 on the HMS Traveled from 1831-1836 on the HMS Beagle.Beagle.

Visited Africa, South America and Australia Visited Africa, South America and Australia studying the similarities and difference in studying the similarities and difference in geology and living things.geology and living things.

He spent 5 weeks in the Galapagos Islands He spent 5 weeks in the Galapagos Islands where he observed Giant Land Tortoises, where he observed Giant Land Tortoises, Marine Iguanas, warm weather Penguins Marine Iguanas, warm weather Penguins and most importantly, the Galapagos and most importantly, the Galapagos Finch.Finch.

Journey of the H.M.S. Beagle on it’s 5 year journey in 1831.

Galapagos FinchGalapagos Finch

Each island has a variation of finch Each island has a variation of finch that is best suited to that particular that is best suited to that particular island. island.

The beaks of the finch gives clues as The beaks of the finch gives clues as to the predominant type of food on to the predominant type of food on that Island. that Island.

This indicates that organisms This indicates that organisms develop to the environment in which develop to the environment in which they live.they live.

Galapagos Finches

A new species of finch evolved by using food on the island that other birds were not using. Its beak indicates the food it ate.

Origin of SpeciesOrigin of Species

After writing for more that After writing for more that 25 years, Darwin published 25 years, Darwin published the Origin of Species after….the Origin of Species after….

Accumulation massive amounts of Accumulation massive amounts of evidenceevidence

Scientific cautionScientific caution

Urging of other scientists, including Alfred Urging of other scientists, including Alfred Wallace.Wallace.

“The Origin of Species” published by Charles Darwin in 1859. This book changed how science looked at the natural world from that time on. It was the most important publication in modern scientific times.

Natural SelectionNatural Selection

1. All organisms have variations of traits1. All organisms have variations of traits2. Some variations allow the organism to 2. Some variations allow the organism to

be successful in a particular environment be successful in a particular environment and produce more offspringand produce more offspring

3. Less successful organisms tend to die 3. Less successful organisms tend to die out rapidly producing little if any offspring.out rapidly producing little if any offspring.

4. Competition for survival weeds out 4. Competition for survival weeds out inferior species. (Survival of the Fittest)inferior species. (Survival of the Fittest)

Natural SelectionNatural Selection

Darwin said, “Darwin said, “Individuals Individuals that have physical or that have physical or behavioral traits that better behavioral traits that better suit to their environment are suit to their environment are more likely to survive and more likely to survive and reproduce than those that do reproduce than those that do not have such traitsnot have such traits.” .”

Darwin also wrote many other books about his travels, coral reefs, beetles and other topics.

His most controversial book was “ The Descent of Man” that outlined mans close connection to the Great Apes.

The Origin of Species and the Descent of Man were banned by church authorities because both books contradicted the belief of Devine Creation.