question: What did Darwin learn about variations by observing breeders ?
answer: breeders were able to select such variations and produce huge differences in many generations of selection
turker_answer: Darwin learned breeders were able to select such variations and produce huge difference in many generations of selection , by observing breeders .
rule-based: Darwin learnt breeders were able to select such variations and produce huge differences in many generations of selection about variations by observing breeders .