Theories of Biological Evolution

Explaining evolution required more than documenting that it happens — biologists needed a mechanism for how heritable change accumulates across generations. Jean-Baptiste de Lamarck offered the first formal theory in 1809; Charles Darwin's natural-selection model followed half a century later and remains the foundation of modern evolutionary biology; Hugo de Vries then proposed that sudden large mutations, not gradual change, drive speciation; and the twentieth-century Modern Synthesis reconciled Darwinian selection with the discoveries of genetics. Two further real-world case studies — indu …