“the field of macroevolution embraces the excitement of seeking an understanding of the breadth of...

“The field of macroevolution embraces the excitement of seeking an understanding of the breadth of life” -Levinton

Taxonomic-based definition

1. “Evolution above the species level”2. Between species evolution (as opposed to

within species, which is microevolution)

Splitting vs. Budding

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Change in bothdescendants

Change in onedescendant

Bottleneck Effect

• Extreme form of Genetic Drift.• Entire population goes through this.

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Founders Effect

Extreme form of Genetic Drift

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Founders Effect

BONOBO DISTRIBUTION

What is Macroevolution? Macroevolutionary Questions:

• Big Question 1: How do we establish evolutionary relationships among taxa?

Specific:Who are humans’ closest relatives?

www.bushorchimp.com

Why are there still chimps?

• Science does not say we descended from modern chimps

• Does say humans and modern chimps descended from a common ancestor

• The common ancestor probably had some characteristics of both species.

Macroevolutionary QuestionsBig Question 2. What processes/factors

regulate the rates of evolutionary change?

Specific:Do mice evolve faster thanelephants?

Macroevolutionary Questions:

Specific:Why did dinosaurs become extinct?

Big Question 3: What environmental changes regulated the timing of evolutionary radiations and extinctions?

Macroevolutionary QuestionsBig Question 4. Do extinctions affect the

evolution of other groups?

Specific: Did the Extinction of dinosaursallow the radiation ofMammals?

Macroevolutionary Questions• Big Question 5 – What ecological processes

regulate diversity?

Specific: Did ecology contributeto the “Cambrian explosion”?