Use the Following Information to Answer the Question Below

question 63

Multiple Choice

Use the following information to answer the question below.
Martin Wikelski and L. Michael Romero (Body size, performance and fitness in Galápagos marine iguanas, Integrative and Comparative Biology 43 [2003]:376-86) measured the snout-to-vent (anus) length of Galápagos marine iguanas and observed the percent survival of different-sized animals, all of the same age. The graph shows the log snout-vent length (SVL, a measure of overall body size) plotted against the percent survival of these different size classes for males and females.

Currently the only predators of Galápagos marine iguanas are Galápagos hawks. Iguana body size is not correlated with risk of hawk predation, although small iguanas can sprint faster than large iguanas. If predators (for example, cats) that preferably catch and eat slower iguanas are introduced to the island, iguana body size is likely to ________ in the absence of other factors; the iguanas would then be under ________ selection.

• A) increase; directional
• B) increase; disruptive
• C) decrease; directional
• D) decrease; disruptive

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Definitions:

Generalization

The process of applying findings from a sample to a larger population, assuming the sample is representative.

Validation

The process of verifying that a product, service, or system meets requirements and specifications and fulfills its intended purpose.

Control

In experimental research, the process of holding factors constant to isolate the effect of the independent variable on the dependent variable.

Epistemologies

The study or theory of the nature, sources, and limits of knowledge, reflecting on how we know what we know.