Motoo Kimura, author of the book, The Neutral Theory of Molecular Evolution, published in 1983, more than a hundred years after Darwin's masterpiece.

The picture of Nature revealed by Kimura and Goodenough is new and striking. Nature loves to gamble. Nature thrives by taking risks. She scrambles mating-system genes so as to increase the risk that individual parents will fail to find mates.

Kimura's theory explains the diversity paradox that puzzled Darwin. Why are we surrounded by such an astonishing diversity of birds and insects and microbes? From the point of view of Darwin, a small number of dominant species would have been sufficient. Kimura explains the mystery by invoking the power of genetic drift, which becomes suddenly rapid and effective just when it is needed, when small populations can vary fast enough to become genetically isolated and form new species.

Sewall Wright, then 98 years old but still in full possession of his wits. He gave me a first-hand account of how he read Mendel's paper and decided to devote his life to understanding the consequences of Mendel's ideas. Wright understood that the inheritance of genes would cause a fundamental randomness in all evolutionary processes. The phenomenon of randomness in evolution was called Genetic Drift. Kimura came to Wisconsin to learn about Genetic Drift, and then returned to Japan. He built Genetic Drift into a mathematical theory which he called the Neutral Theory of Molecular Evolution.