Evolution Spring 2014 Theory of Evolution the change

• Theory of Evolution = the change in the inherited characteristics of biological

It was previously thought that you could obtain traits in your lifetime to be

Darwin’s Theory of Natural Selection • Natural Selection: Species that are more “fit” will

In your notes… • 1) Write 2 traits or adaptations that would make a

Darwin’s Finches • Darwin observed many species of finches on the Galapagos Islands

• One difference he noticed were the beak sizes • The species were

Adaptations • Adaptations = favorable traits that help an organism to survive • Finch

Types of Selection • Directional: One end of the phenotype is selected for •

Migration • Migration occurs when individuals move between populations

Genetic Drift • =Random events that happen to a population

• Bottleneck Effect: the surviving population does represent the larger population – Many

Evidences of Evolution • 1) Fossil evidence – Fossils are proof that species once

Fossil Evidence • 2) Embryo Development – Most animal’s early embryos have very similar

Evidences of Evolution • 3) Homologous Structures – Many animals share very similar structures,

Evidence of Evolution • 4) Genetic likeness – Many species share the exact or

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Evolution Spring 2014

• Theory of Evolution = the change in the inherited characteristics of biological populations over time – Does not happen quickly!! – Evolution is a theory!

It was previously thought that you could obtain traits in your lifetime to be passed on to your children • “Inheritance of Acquired Characteristics” – Example: Giraffes stretch their necks more and more

Darwin’s Theory of Natural Selection • Natural Selection: Species that are more “fit” will be more likely survive and have offspring

In your notes… • 1) Write 2 traits or adaptations that would make a species more “fit” – Example: Cheetah’s speed • 2) Write 2 things that would make a species less “fit” – Example: Being too brightly colored so you cannot blend in

Darwin’s Finches • Darwin observed many species of finches on the Galapagos Islands

• One difference he noticed were the beak sizes • The species were similar enough that Darwin assumed they were from the same population

Adaptations • Adaptations = favorable traits that help an organism to survive • Finch beaks evolved and changed when the finches were exposed to different types of food and environmental pressures

Types of Selection • Directional: One end of the phenotype is selected for • Stabilizing: Intermediate phenotypes are selected for • Disruptive: Extreme ends are selected for

Migration • Migration occurs when individuals move between populations

Genetic Drift • =Random events that happen to a population

• Bottleneck Effect: the surviving population does represent the larger population – Many alleles are lost

Evidences of Evolution • 1) Fossil evidence – Fossils are proof that species once existed that modern life has evolved from

Fossil Evidence • 2) Embryo Development – Most animal’s early embryos have very similar structures

Evidences of Evolution • 3) Homologous Structures – Many animals share very similar structures, even though they may be adapted to different traits

Evidence of Evolution • 4) Genetic likeness – Many species share the exact or very similar genes for different proteins