The Following Questions Refer to the Evolutionary Tree in Figure

question 39

Multiple Choice

The following questions refer to the evolutionary tree in Figure 22.2.
The horizontal axis of the cladogram depicted below is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V-Z) represent various common ancestors. Let's say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.

Figure 22.2
-Which of the five common ancestors, labeled V-Z, has been least successful in terms of the percent of its derived species that are extant?

• A) V
• B) W
• C) X
• D) Y
• E) Z

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Definitions:

Population Proportion

The fraction or percentage of the population that shares a particular characteristic or attribute.

Chi-squared Goodness-of-fit

A specific type of goodness-of-fit test that uses the chi-squared statistic to test the hypothesis that an observed frequency distribution fits a claimed distribution.

One-tail Test

A statistical test where the region of rejection is on only one side of the sampling distribution, used when testing a directional hypothesis.

Population Proportion

The ratio of members in a population that have a particular attribute, often estimated from sample data.