It Was Once Thought That Cetaceans Had Evolved from an Extinct

question 69

Multiple Choice

It was once thought that cetaceans had evolved from an extinct group of mammals called the mesonychids. If, in the future, it is determined that some organisms currently classified as cetaceans did actually evolve from mesonychids, whereas other cetaceans evolved from artiodactyl stock, then what will be true of the order Cetacea?

• A) It will be paraphyletic.
• B) It will be polyphyletic.
• C) It will need to be thrown out or modified if classification is to reflect evolutionary history.
• D) Two of the responses are correct.

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Definitions:

Room Temperature

A general description of a comfortable indoor environment, typically considered to be around 20°C (68°F) to 22°C (72°F).

Noise Level

The measurement of the ambient level of sound, often referring to the background sound present in a given environment.

Internal Validity

The degree to which a study’s results are attributable to the independent variable, rather than other factors, indicating the study accurately reflects the relationship being tested.

Confounding Variable

An external influence that can affect the results of an experiment by varying along with the independent variable, potentially misleading the outcome.