5.1: EVIDENCE FOR EVOLUTION

Understandings

• Evolution occurs when heritable characteristics of a species change.

• The fossil record provides evidence for evolution.

• Selective breeding of domesticated animals shows that artificial selection can cause evolution.

• Evolution of homologous structures by adaptive radiation explains similarities in structure when there are differences in function.

• Populations of a species can gradually diverge into separate species by evolution.

• Continuous variation across the geographical range of related populations matches the concept of gradual divergence.

Applications and Skills

• A: Development of melanistic insects in polluted areas.• A: Comparison of the

pentadactyl limb of mammal, birds, amphibians, and reptiles with different methods of locomotion.

Charles Darwin1809 - 1882

“……can we doubt (remembering that many more individuals are born than can possibly survive) that individuals having any advantage, however slight, over others, would have the best chance of surviving and procreating their kind? On the other hand, we may feel sure that any variation in the lease injurious would be rigidly destroyed. This preservation of favourable variations and the rejection of injurious variations, I call NATURAL SELECTION.” – On the Origin of Species

Half-life

Whale evolution: http://www.youtube.com/watch?v=I2C-3PjNGok

The Bizarre Truth About Pure Breeds

http://media.outsideonline.com/images/dog-breeds-now-and-then_fe.jpg

http://www2.edc.org/weblabs/ExploringEvolution/evolution.swf

Adaptive Radiation

Transient Polymorphism

TOK

• What are the arguments for and against the peppered moth as an example of evolution?• Should it continue to be used in classrooms as an

example?• When there are disagreeing sides, which one

should we believe?• What have you learned from TOK to help you

make your decision?

• Vocab• Heritable• Speciation• Homologous

structures• Analogous structures• Artificial selection• Adaptive radiation• Niche• Natural selection• Selective pressure

• Pg 222- Challenge Yourself• Pg 228- Exercises

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