The writer is considering adding the following sentence to the passage (placed after Sentence 3):
"Darwin, in particular, was deeply concerned that Kelvin's timeline did not allow enough time for natural selection to produce the Earth's diverse life forms."
Should the writer make this addition?
[1] In the mid-nineteenth century, the physicist Lord Kelvin attempted to calculate the age of the Earth by measuring its geothermal heat loss. [2] Assuming the Earth began as a molten sphere and had been cooling steadily, Kelvin estimated its age to be between 20 and 400 million years. [3] While this calculation was far longer than the biblical timeline accepted by many at the time, it was hotly contested by geologists and biologists, who argued that evolutionary and geological processes required billions of years. [4] Kelvin's calculations, though mathematically rigorous, were ultimately flawed because he was unaware of radioactivity, which releases heat within the Earth's interior and delays cooling. [5] The discovery of radioactive decay by Henri Becquerel in 1896 eventually provided the key to accurately dating the planet at 4.5 billion years.
- Yes, because it offers a specific, relevant example of a biologist whose theories were challenged by Kelvin’s timeline, supporting the general statement in Sentence 3.Answer
- BYes, because it introduces the primary scientific evidence that was ultimately used to disprove Kelvin’s geothermal calculations.
- CNo, because it introduces a discussion of evolutionary biology that is unrelated to the paragraph's focus on geological time.
- DNo, because it deviates from the passage's primary focus on Lord Kelvin's contributions to the field of physics.