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Quiz Time! Put away all materials except for

something to write with.

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Aim: How does natural selection work? Date: September 13, 2013

Agenda

S  Lamarck

S  Darwin

S  Natural Selection

S  Sickle Cell Disease

S  Group Work

Lamarck

S  Idea that organisms can pass on traits acquired during its life to offspring.

S The changes are driven by needs of the animal.

S Also thought things were always trying to become more complex.

Darwin

S Traveled to Galapagos islands on HMS Beagle at age of 22.

S Noticed strange fossils and wildlife. Began to construct theory of natural selection.

Darwin

S Came with theory around the same time as Alfred Wallace.

S Published On the Origin of Species

Natural Selection

1.   There is variation in traits

2.   There is differential reproduction

3.   The traits can be passed on

Natural Selection

S  http://media.hhmi.org/fittest/HD/human_selection_HD.m4v

S  In your tribes, answer the following questions by discussing with one another. You will be asked to explain answers.

1.   Why did sickle cell disease became so prevalent in certain East African populations?

2.   Is the following statement true or false? “Malaria caused the sickle cell allele to appear." Justify your answer in one or two sentences.

3.   Due to climate change, the range of malaria is expected to spread to areas where it was previously not a problem. Given this piece of evidence, predict what will happen to the frequency of the sickle cell allele in areas where malaria is introduced.