Which of the following is a hypothesis the researchers were testing in this study? Which of the following is a hypothesis the researchers were testing in this study? Through evolution, periwinkle populations with a history of predation by crabs have become more vulnerable to crab predation. Through evolution, periwinkle populations without a history of predation by crabs have become less vulnerable to crab predation. Through evolution, all periwinkle populations have become less vulnerable to crab predation. Through evolution, periwinkle populations with a history of predation by crabs have become less vulnerable to crab predation.