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Day 5: Evolution.  Traveled on the Beagle to the Galapagos Islands  Studied 13 species of finches on the islands  Hypothesized that all originated.

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Presentation on theme: "Day 5: Evolution.  Traveled on the Beagle to the Galapagos Islands  Studied 13 species of finches on the islands  Hypothesized that all originated."— Presentation transcript:

1 Day 5: Evolution

2  Traveled on the Beagle to the Galapagos Islands  Studied 13 species of finches on the islands  Hypothesized that all originated from 1 ancestor  Explained his theory of NATURAL SELECTION  Published in On the Origin of Species  Influenced by Lyell and Wallace  Strayed from Lamarck’s “inherited traits” theory

3  Survival of the Fittest  Fit = best adapted to environment for survival Mice will display gray coloring rather than white

4  Adaptations  Changes in response to the environment and becomes a new species  Required to survive in the changing world  Reproductive Isolation  A species is separated and becomes two separate species

5  Speciation  Creation of a new species  A species can mate and produce viable offspring  Extinction  A species ceases to exist  Can occur gradually (rainforest plants) or as a mass extinction (dinosaurs)  Biodiversity  Number of different species/organisms  Biodiversity inside a classroom is much lower than the biodiversity outside  Inside: humans, insects  Outside: humans, insects, plants, animals, etc.

6  Gene Pool  Genes available for reproducing  Gene Flow  Introducing genes from one gene pool into another gene pool

7  Gradualism  Punctuated Equilibrium

8  Radioisotope Dating  Provides EXACT age of fossils  Uses the half-lifes of radioactive isotopes (Carbon-14)  Relative Dating  Provides APPROXIMATE age of fossils  Generally, older fossils are found in rock layers beneath younger fossils

9  Analogous Structures  Vestigial Structures  Used by common ancestor but no longer necessary  Homologous Structures

10  Stabilizing Selection  Selects for the central trait  Directional Selection  Selects for one extreme trait  Disruptive Selection  Selects for both extreme traits

11  Variations exists within populations.  Organisms compete for limited natural resources.  Organisms produce more offspring than can survive.  Individuals with variations suitable for their habitat survive and reproduce.

12  Natural selection allows for the resistant bacteria and pests to survive and reproduce offspring that are also resistant  Antibiotic resistance  The overuse of antibiotics leads to “superbugs”  Pesticide resistance  Farmers must increase the use of pesticides on crops as pests become immune/resistant to doses


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