Download 1-4 Evolution and Classification.notebook

1­4 Evolution and Classification.notebook
January 04, 2016
Evolution and Classification
Lesson 1­4
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1­4 Evolution and Classification.notebook
January 04, 2016
How are evolution and classification related?
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1­4 Evolution and Classification.notebook
January 04, 2016
How are evolution and classification related
When Linnaeus developed his classification system, people thought that species never changed
1859
British naturalists
Charles Darwin
Published an explanation for how species could change over time.
Evolution­ process of change over time
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1­4 Evolution and Classification.notebook
January 04, 2016
Darwin thought evolution occurred by natural selection
Natural selection ­ the process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species
As understanding of evolution increased, biologists changed how they classified organisms
understood organisms may be similar because of common
ancestor or evolutionary history
most similar= more recent common ancestor
Today's classification considers the history of species
Species with similar evolutionary histories are classified more closely together
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1­4 Evolution and Classification.notebook
January 04, 2016
Branching Tree Diagrams
A branching tree diagram shows probable evolutionary relationships among organisms and the order specific characteristics have evolved
start with common ancestor
organisms grouped according to shared derived characteristics­ traits that the common ancestor of a group had passed on to its descendants
organisms to the right of the trait have that trait in common
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1­4 Evolution and Classification.notebook
January 04, 2016
ability to purr
retractable claws
platypus
give birth to live young
hair and mammary glands
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1­4 Evolution and Classification.notebook
January 04, 2016
Determining Evolutionary Relationships
To determined the evolutionary history of a species scientists compare structures
also compare chemical makeup of the organism cell
Sometimes unrelated organisms evolve similar characteristics because they evolved in similar environments
ex. organisms that move through water
or similar types of food
The process by which unrelated organisms evolve characteristics that are similar is called convergent evolution
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1­4 Evolution and Classification.notebook
January 04, 2016
Sometimes when studying the chemical make­up of an organism, new information discovered can result in re­
classification
ex. skunks and weasels
150 years ago they were classified in the same family
when they compared the nucleic acids they noticed differences
put into separate families
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