What did the Scottish geologist and plant-breeder James Hutton claim about a possible evolutionary mechanism similar to natural selection (many years before Charles Darwin and Alfred Russel Wallace)?
a. that only natural selection, not artificial selection, could lead to improved plant and animal species
b. that selection for heritable variation could improve species, but not varieties, of plants and animals
c. that selection for heritable variation could improve varieties, but not species, of plants and animals
d. that only artificial selection, not natural selection, could lead to improved plant and animal species
e. that artificial selection of crops and livestock improves plants and animals more than natural selection