Anti-evolutionary thinkers sometimes argue that natural selection could not produce a complex structure like the vertebrate eye. They claim that all of the parts of the eye must have arisen at once, asking why natural selection would favor the development of part of an eye that is not yet capable of forming a focused image. Which of the following statements is consistent with a survey of eye structure in the molluscs?
A. The argument has a great deal of merit. Only full-blown image-forming eyes are present in modern organisms.
B. There are many intermediate stages of eye complexity that fulfill different adaptive functions.
C. The vertebrate eye is the ancestral form, and other types of organisms have degenerate eyes that have lost most of their original structure and function.
D. The vertebrate eye works in a way that is completely different from the eyes found in molluscs and other invertebrates.
Answer:B
Anti-evolutionary thinkers sometimes argue that natural selection could not produce a complex structure like the vertebrate eye. They claim that all of the parts of the eye must have arisen at once, asking why natural selection would favor the development of part of an eye that is not yet capable of forming a focused image. Which of the following statements is consistent with a survey of eye structure in the molluscs?
A. The argument has a great deal of merit. Only full-blown image-forming eyes are present in modern organisms. B. There are many intermediate stages of eye complexity that fulfill different adaptive functions. C. The vertebrate eye is the ancestral form, and other types of organisms have degenerate eyes that have lost most of their original structure and function. D. The vertebrate eye works in a way that is completely different from the eyes found in molluscs and other invertebrates.