Richard Lewontin's "The Genetic Basis of Evolutionary Change" argues that current population genetic theory is inadequate to explain the vast hereditary variation revealed by molecular techniques and its role in the origin of new species. Lewontin proposes a shift in theoretical focus from the independent evolution of individual genes to the evolution of the genome as a whole, emphasizing the critical importance of gene interactions in evolutionary change.
The book surveys experimental findings in molecular evolution, highlighting the substantial amount of hereditary variation present in individuals and quantifying genetic changes relevant to speciation. It addresses the ongoing challenges in explaining the origin and maintenance of this variation, questioning whether adaptive evolution effectively utilizes this common diversity. Lewontin calls for new theories to integrate genomic evolution, moving beyond the limitations of existing population genetics.
Key concepts
- Hereditary variation — The vast amount of differences in heritable traits among individuals revealed by molecular techniques.
- Genetic changes in origin of new species — Quantifiable alterations in genes that occur during the process of speciation.
- Population genetic theory — Existing theoretical frameworks for understanding the forces that operate on genetic variation within populations.
- Evolution of the genome as a whole — A theoretical approach that considers the interconnected evolution of all genes within an organism's genome.
- Independent evolution of each gene — The traditional view of genes evolving as separate entities, which Lewontin argues is insufficient.