Sex, Drugs and Disaster: The Extinction of Dinosaurs
1. Before you read, decide which of three explanations for the extinction of the dinosaurs you like best. Write an explanation of why you like it.
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.
1.
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
The
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.
1.
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
The