> "Are eggs vertebrate or not"
>
> Since they don't have a skeleton, they are not vertebrates. Eggs
> could be a food we are genetically adapted to, just like invertebrates.

What we need to clarify here, in my opinion, is the reason why we should
care whether something is vertebrate or not.  Why would food choices of our
ancestors be divided along the vertebrate/invertebrate line?  Seems to me it
would be divided along the lines of whether a particular animal food was
available or not.

As to whether eggs are vertebrates or not, the answer is that it depends on
what animal the egg comes from!  Eggs from vertebrates are vertebrates!.  It
doesn't matter that the skeleton hasn't developed yet.  We're talking about
a classification, not whether there's a spine on your plate.  Saying eggs
are invertebrates because they have no spine nullifies the whole
vertebrate/invertebrate delineation.  By that reasoning, I could say that
chicken livers are invertebrate because the liver has no spine!

C