The debate over the validity of evolutionary theory may be real enough when it comes to religious belief and cultural outlook. But it has nothing to do with science. No evidence seriously contradicts the idea that the plant and animal species found on Earth today are descended from common ancestors that existed long ago. Indeed, the evidence for natural selection is infinitely stronger than it was when Charles Darwin proposed it 150 years ago, mainly because later discoveries in the field of genetics supplied the biological mechanisms to explain the patterns that Darwin and his contemporaries were observing.

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