The Upper Forelimbs of Humans and Bats Have Fairly Similar

question 53

Multiple Choice

The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data?

• A) Humans and bats evolved by natural selection, and whales evolved by Lamarckian mechanisms.
• B) Forelimb evolution was adaptive in people and bats, but not in whales.
• C) Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.
• D) Genes mutate faster in whales than in humans or bats.
• E) Whales are not properly classified as mammals.

---

Definitions:

Independent Variable

A variable in an experiment or study that is manipulated or controlled by the researcher to test its effect on the dependent variable.

Exact Value

The precise, unrounded value of a number or expression without any approximation.

Sample Coefficient of Correlation

A measure indicating the degree and direction of linear relationship between two quantitative variables within a sample.

Estimated Regression Line

A line calculated from sample data that best fits the scatterplot of the data points, used to make predictions.