The Fifth of the Five Ways

[GrandizerII]

Thomist: The Teleological Argument is actually about the per se cause of the tendency of each creature to an end. The origin of species via evolution is completely irrelevant, as evolution is a per accidens cause.

I answer that,

Natural selection and deep time results in the simulacrum of design. Aquatic mammals resemble fish because their form, after many reproductive iterations, is optimal for their environment. A valid argument from design must first rule out whether the design is merely apparent.

It might be beneficial to ask that person to elaborate on what they mean exactly, so we can avoid responding to strawman arguments.