It Is Difficult to Imagine How Only Part of an Adaptation

question 25

Multiple Choice

It is difficult to imagine how only part of an adaptation could function, but Darwin explained this. How would he answer the question, "What good is 5% of an eye?"

• A) Once an organism has the first 5% of an adaptation, the rest will quickly evolve.
• B) Five percent of an eye is always better than a full eye since it is easier to grow. The difficulty is in explaining fully formed eyes.
• C) Since variation is random, we don't expect to see more than about 5% of an eye in any species.
• D) Five percent of an eye, perhaps a simple light-sensitive spot, is often better than having no eye at all.

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Definitions:

Artery

A blood vessel that carries oxygenated blood away from the heart to various parts of the body.

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A brain condition associated with repeated head impacts, not necessarily concussions, leading to neurodegenerative disease which can result in behavior, mood, and cognitive problems.

Concussions

Brain injuries caused by a blow to the head or a sudden jolt that can disrupt normal brain function.

Autopsy

A postmortem examination to discover the cause of death or the extent of disease.