Sex: Testes function only in a narrow range of temperature. (Those of mammals hang externally in a scrotal sac because internal body temperatures are too high for their proper function.) A worldwide rise in temperature at the close of the Cretaceous period caused the testes of dinosaurs to stop functioning and led to their extinction by sterilization of males.
Drugs: Angiosperms (flowering plants) first evolved toward the end of the dinosaurs’ reign. Many of these plants contain psychoactive agents, avoided by mammals today as a result of their bitter taste. Dinosaurs had neither means to taste the bitterness nor livers effective enough to detoxify the substances. They died of massive overdoses.
Disasters: A large comet or asteroid struck the earth some 65 million years ago, lofting a cloud of dust into the sky and blocking sunlight, thereby suppressing photosynthesis and so drastically lowering world temperatures that dinosaurs and hosts of other creatures became extinct.
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2. While you read, consider these questions:
What distinguishes speculation from a claim?
What are the characteristics of a testable claim?
Is it possible to prove that a claim is correct?
Who decides if a claim is good or bad?
After you read, discuss each of the following statements in writing:
Scientific ideas are invented.
Scientific ideas are discovered.
The ultimate authority in science is evidence.
The ultimate authority in science depends on the stature of the scientist.
With enough evidence, a scientific explanation can be proven.
With enough evidence, a scientific explanation can be disproven.
Scientific explanations develop to a point where they are beyond question.
Scientific explanations are never beyond question.
Sex, Drugs, Disasters, and the Extinction of Dinosaurs
Stephen Jay Gould
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