Special Edition

November 6, 2012 Evolution and Gene Expression

Suggested Reading

Prior to accepting the daily challenge, read the following articles.

Mammalian gene expression.
Neutral Theory.

Evolution has its base in genetics. All variation starts with mutation. The addition, deletion or change in the nucleotide sequence of a coding region can result in protein changes. Any mutation, if it has an expressed effect, then becomes subject to the mechanism of Natural Selection.

A great example of this nucleotide alteration is seen in Sickle Cell Anemia. A change in one nucleotide causes a conformational change in the β-hemoglobin chain, which causes the entire expression of the disease (the altered hemoglobin molecule is known as HbS). Review the β-hemoglobin gene sequence and see how just one point-mutation can have such a strong effect. Also note, this is a change in the third nucleotide of a codon.

Optional Challenge

Your task today is to discuss the relationship DNA changes and Gene Expression has with evolution. Sit with the concept for a moment, and come up with a coherent discussion. Feel free to use models such as Sickle Cell Anemia. Remember, this alteration in gene expression sets up the diversity of the population. Natural Selection then acts on the new phenotype.
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