We are separate from animals, a unique creation in His image--contrary to evolution that states we are merely evolved animals. Not one verse you have posted has proven your theory.
Each individual life form is according to God's design at each
moment of it's existence. So you need to disqualify
that position,
not the position of heathens.
Your position is that God needed to put a mark on Cain, so that as he
wandered the world, his brothers, sisters, nieces and nephews would
be able to identify him and not kill him.
That's quite a stretch for him to be so worried about immediate family
not listed anywhere in scripture.
Your position is that all of Adam and Eve's children intermarried.
That's quite a stretch for people not listed anywhere in scripture
and in light of rules that prohibit such behavior.
You need to add a whole lot of sisters and brothers to scripture (not found in scripture)
to all intermarry (not found in scripture) to fill the world and have
Cain worried about being killed by them.
In my investigation of this problem of adding 100's of offspring
to intermarry and fill the world, I noticed that Adam and Eve were
not created Ex Nihilo. I also noticed that "all life" had previoulsy
been produced
by the land.
I'm not trying to prove any position. I'm attempting to change
what scripture says as little as possible. Generations of people
KNOW
that you shouldn't breed with your siblings, scripture states this,
and so we can't expect God to have them swallow that story
without comment and conditional approval by scripture.
Without any noted comment on insest, we must assume that
New Testament writers knew about humans outside of the Garden
Paradise.
These people are who Cain was afraid would kill him and who
married with Adams offspring.
So Adam would not be the first food producer. Instead of living
a "life of ease" fully under God's communion, with God walking
even at his side, instead Adam was kicked out of paradise and
would have to work hard to produce food and Eve would bear
children in pain, not under the guiding hand of God, who evidently
would have children born without pain. It would have been nice.
On the other hand, perhaps Adam was the first to till the soil.
Hard to say.