Key Idea.
Section 1
Solving the Newt Mystery
We can now explain the rough-skinned newt mystery. The environmental pressure was a predator: the Garter Snake.
Snakes began eating the newts. In this environment, "high poison" became an adaptive trait. Newts with low poison were eaten and did not reproduce. Newts with high poison survived the snakes and reproduced.
Section 2
Evolution in Action
Over many generations, the "high poison" genes were passed down repeatedly, while "low poison" genes were lost.
Today, the population is extremely poisonous not because individual newts decided to change, but because Natural Selection removed the less poisonous individuals over hundreds of years.
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Section 1
Solving the Newt Mystery
We can now explain the rough-skinned newt mystery. The environmental pressure was a predator: the Garter Snake.
Snakes began eating the newts. In this environment, "high poison" became an adaptive trait. Newts with low poison were eaten and did not reproduce. Newts with high poison survived the snakes and reproduced.
Section 2
Evolution in Action
Over many generations, the "high poison" genes were passed down repeatedly, while "low poison" genes were lost.
Today, the population is extremely poisonous not because individual newts decided to change, but because Natural Selection removed the less poisonous individuals over hundreds of years.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter