@Romeo Fabulini,
no that's not the case. I don't know the story of spiders except for th fossil record of their history, but ALL times the evolution of a complex system (like echo location or flight) occurred step by step with an original function being totally different than a final function.
The ID boys hve tried to show that "Irreducible Complexity", when carried back to some beginning, demonstrates that a function just "ppears" out of nowhere (is , substitute God).
Every one of IDers irreducible complexity demonstrations hs been debunked by science. The most famous was Michael Behes "complex enzyme cascade that defined blood clotting in mammals)
The same cascade, except progressively simpler and simpler could be traced to lower animals until finally, in annelids, it was clearly shown that only one chemical enzyme was required to clot the "blood" of a worm.
Ardipithecus is another example of gradualism in achieving something. This fossil was somewhat like us except, besides being an upright walker, its feet were prehensile with a grasping big toe and it had a teeny ape-like skull.
Gradualism is still the example where we see the most fossil changes in phenotypes. Punctuated Equilibrium, though maybe more frequent a mechanism, doesn't leave well made traces in the sedimentary record because geology isn't necessarily being cooperative to make fossils. Its a forensic science, not a worldview
