Acuticle occurs on the surface of organisms of many phyla and appears to be an advantageous feature. why have higher organisms not retained this structure?

While the cuticle has several advantages such as protection, they do not confer much advantage to larger eukaryotes. This is because of their limiting factor to growth (size). The cuticle would also restrict development of different skin structures such as fur.  Additionally, while the cuticle provides leverage for muscular movements on arthropods, nematodes, and flatworms, it is not necessary for larger animals since the same function is rendered by the endoskeleton.

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation: