Question

which is a way that paleontologists have contributed to humans understanding of the history of life?
they found evidence that climate has not changed significantly.
they grouped organisms by the period in which they existed
they discovered that the first humans lived with dinosaurs.
they learned that life has existed since earth was created

Explanation:

Paleontologists study fossils. By examining fossils, they can group organisms according to the geological periods in which the organisms existed. Climate has changed significantly over Earth's history (so the first option is wrong). The first humans did not live with dinosaurs (dinosaurs went extinct about 66 million years ago, and the first humans appeared much later, so the third option is wrong). Life did not exist since Earth was created (Earth formed about 4.54 billion years ago, and the earliest evidence of life is from about 3.5 billion years ago, so the fourth option is wrong).

Answer:

They grouped organisms by the period in which they existed.