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DNA IS AT THE HEART OF EVOLUTION
Darwin Day Celebration
AN INTERNATIONAL RECOGNITION OF SCIENCE AND HUMANITY

2. The Role of Inheritance

The genetic coding for traits is performed by the sequences of DNA nucleotides. But how do the DNA sequences get distributed to the offspring of an organism? This is the process of inheritance, and was one of the missing concepts that Darwin had to guess about when he first wrote On the Origin of Species. Part of the story of inheritance came from the work of Gregor Mendel, an Austrian monk who carefully bred kinds of pure bred pea plants, and then studied the ratios of various characteristics in the offspring. He was able to explain his results with the ideas that parent plants each contributed one copy (“allele”) of a particular “gene”, and the offspring contained a pair of alleles for each kind of gene. Depending on the nature of the two alleles in that pair, various traits could be manifest by the offspring.

Sources and Further Reading:

The Monk in the Garden : The Lost and Found Genius of Gregor Mendel; by Robin Marantz Henig

How are genes inherited?

Variation, Inheritance, and Evolution