On the Genesis of Species

The author examines and critiques the explanatory reach of natural selection, arguing it cannot account for infinitesimal incipient stages of complex organs and for the simultaneous modification of many individuals. He analyzes cases such as the giraffe's neck, mimicry, eyes and ears, mammary glands, and other morphological coincidences to argue for multiple origins of similar structures and for causes beyond natural selection. The work surveys comparative anatomy, development, and geographical distribution, considers the reception of evolutionary ideas within religious debate, and suggests that prevailing evolutionary explanations require supplementation to resolve persistent difficulties.