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About This Quiz
An atavism is a trait from a distant evolutionary ancestor that has reappeared in a modern-day creature, like a whale with legs. A whale with legs? Take this quiz and learn about atavistic whales and other animals.
What is an atavism?
It is any unusual physical deformity.
It refers to a distasteful stereotype.
It's a trait of a distant ancestor that has reappeared.
Correct Answer
Wrong Answer
An atavism is a trait of a distant ancestor that reappears in the modern day.
One theory says that genes, such as those governing growth of a tail, are not lost in evolution but are inactive. During the development of the embryo something unknown "turns on" that gene.
Back to the whale: How could it once have had legs?
Legs used to help them swim but later became a nuisance and were lost.
They used them to fight with until they perfected other means.
They once walked on dry land.
Correct Answer
Wrong Answer
Scientists believe that millions of years ago the ancestors of the whale walked on land. At some stage they took to the sea, probably in search of food, and since they no longer needed their legs in the water, eventually lost them.
