...between varieties of the same species, and the greater differences between species of the same genus. The external conditions of life, as climate and food,...diminishing organs, seem to have been more potent in their effects. Homologous parts tend to vary in the same way, and homologous parts tend to cohere. Modifications...

...establish in a demonstrable way and left Charles Darwin (1859, p. 137) lamenting, "Not in one case out of a hundred can we pretend to assign any reason why this or that part differs, more or less, from the same part of the parents." Bateson (1894, p. 12) opined that "the only...

...Developmental Biology of the Heart Our ignorance of the laws of variation is profound. Not in one case out of a hundred can we pretend to assign any reason why this or that part differs, more or less, from the same part in the parents. But whenever we have the means of instituting...

...and p. 150 he says : " Our ignorance of the laws of variation is profound. Not in one case out of a hundred can we pretend to assign any reason why this or that part differs, more or less, from the same part of the parents." But this is not Darwin's fault, it lies...