Question

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. There are many intermediate stages of eye complexity that fulfill different adaptive functions.
B. 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.
C. The argument has a great deal of merit. Only full-blown image-forming eyes are present in modern organisms.
D. The vertebrate eye works in a way that is completely different from the eyes found in molluscs and other invertebrates.

Answer 1

The statement that is consistent with a survey of eye structure in mollusks is that many intermediate stages of eye complexity fulfill different adaptive functions. The correct option is A.

Step-by-step explanation:

The statement that is consistent with a survey of eye structure in the mollusks is A. Many intermediate stages of eye complexity fulfill different adaptive functions.

One example of an intermediate stage of eye complexity in mollusks is found in cephalopods such as squids and octopuses. These animals have a more developed eye structure than other mollusks, with a lens and retina that allow for better focus and image formation.

However, their eye structure is still different from the complex vertebrate eye, showing a gradual progression of eye evolution. This supports the idea that complex structures like the vertebrate eye could have evolved through natural selection acting on simpler eye structures over time.