Not sure if this is the right place to post this but...
How do you define the complexity of an organism?
One evidence of the occurrence of macroevolution is the fossil record observation that invertebrates were on the earth much longer than vertebrates. Thus showing that "complex" organisms evolved from "simple" organisms. But how do you define a complex organism? Having more cells? Having a skeletal structure? Is it possible to say that an organism with a skeletal structure is "more complex" than an organism without it and why?
Well, to be precise, which I am even in my sleep, it is possible to say it, but I challenge anyone to mean anything by it.
Are you sure this is true, I mean I'm looking at a wikipedia article right now saying "More complex organisms such as...". I mean can't you say that a multicellular organism is more complex than a single-celled organism?