Ah well, there's the crunch, I don't take the bible as an authoritative source for our origin, so while we have that major difference in opinion we will never see eye to eye on evolution. The exchange is a bit pointless.
I'm not sure what you mean "someone can develop beyond his siblings", if you mean some people are more academically gifted than others then sure. I'm the only graduate among my siblings, but to say I "developed beyond them" is just putting an arbitrary label of superiority on academic achievement. If I was living in the middle of a forest, having a higher IQ than my siblings might be seen as a weakness. Physical strength and dexterity might be highly valued in that culture, so my 6.5 foot younger brother would be said to have "developed beyond"
me. My extra "intelligence" might make me more curious than my siblings, so I end up getting killed early because I'm poking a snake with a stick while they chill out. Natural selection!
Whatever, just because I might have a higher IQ that doesn't make me a different animal, a different species does it?