I majored in biology before engineering. I disagree with your assessment.
Your qualification of "appears to be" is where I agree, on the surface. But looking further, each creature is pretty much it's own. Classifications of flora and fauna tend to both attempt to create a chain from "simplest" to more complex forms of life and segregate the various classifications. However, the gaps segregating the classifications, particularly in the fossil record is what spawned the theory of macro-mutant theory of evolution, IIRC. Again, it requires great faith, IMO.
