Changing Scientific Knowledge

Question 1

A class is studying two different explanations for why the long-necked dinosaur Brachiosaurus could reach high trees. Explanation A was proposed after one bone was found with a short neck. Explanation B was proposed after scientists examined three different skeletons, a fossilized trackway, and a recent 3‑D scan of the vertebrae. Which statement best follows how scientists decide which explanation is strongest?

Accepted Answer

The explanation that is backed by the most evidence from several sources is the best one.

Answer

The explanation that looks the most surprising is the best one.

Answer

The explanation that was written down first is the best one.

Answer

The explanation that comes from the most famous scientist is the best one.

Question 2

Which statement best illustrates a dinosaur hypothesis that was revised after a new fossil discovery?

Accepted Answer

Paleontologists originally thought the huge sauropod Apatosaurus ate only low‑lying plants because its neck was believed to be too weak to reach high foliage; later, a fossil with specially shaped neck vertebrae demonstrated the neck could support a raised head, leading scientists to revise the feeding‑height idea.

Answer

Scientists once thought all Tyrannosaurus rex had short arms, but a newly found T. rex skeleton with unusually long forearms showed that some individuals had longer arms, so the idea about arm length was changed.

Answer

Researchers believed Stegosaurus walked on its hind legs because its tail was stiff, and finding a fossil with a flexible tail proved it could not walk upright.

Answer

Scientists originally said the feathered dinosaur Archaeopteryx could not fly because its wings were too small, but a new fossil showing larger wing bones proved it could soar across oceans.

Question 3

Scientists are trying to decide whether the dinosaur Dryosaurus lived in groups. Dr. Vega argues that it did because she has three separate pieces of evidence: (1) several Dryosaurus skeletons are found together in the same rock layer, (2) many of those bones show bite marks that match Dryosaurus teeth, and (3) pollen from the same layer shows the same types of plants were present, suggesting a shared environment. Dr. Ortiz also says Dryosaurus lived in groups, but he only cites the first piece of evidence (the grouped skeletons). Which statement best explains why Dr. Vega’s idea is considered the stronger scientific explanation?

Accepted Answer

Because it is supported by several independent lines of evidence, while Dr. Ortiz’s relies on just one.

Answer

Because it was published in a more recent scientific journal.

Answer

Because Dr. Vega is a better‑known paleontologist.

Answer

Because both scientists agree, so the idea must be correct.

Try three questions

Which statement best illustrates a dinosaur hypothesis that was revised after a new fossil discovery?

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