I find it interesting that a number of points have appeared here relatively quickly.
The first being that we are an evolution, the second that we are an evolution of systematic creation and the third that we are a defected species.
If I may, I would just like to comment on each point.
1. Evolution.
Plain and simple biological, genetic, environmental evolution and species divergence, growth and change. Many circles, even today, debate Charles Darwin's theories of evolution and whilst modern science may proove that his thought-pool was hindered or inaccurate you can't easily put up a placard as say 'Darwin is a Liar and a Cheat, a Mad Man'. In essence, I like AlexandriaC's reference to a tree, in that species evolves like branches from a primary source, the further back in time we go the narrower these branches are and the number becomes smaller.
I would like to argue that due to genetic and external impacts a group of people have evolved with cerebral adaptations whereby the body compensates X for Y.
So, in feeding, the body gets a source from which it interprets a maximum benefit, compared to other sources of energy. In evolutionary theory, if this gene is dominant it will pass on through the ages, if not it will perhaps appear as a recessive trait in many humans only to be awakened by alterations to the brain. Evolution will resolve this if it chooses too.
2. Biblical Evolution - Adam and Eve, Cane and Lilith.
I understand the belief structure behind how through the creation of humans, thanks fo God's punishment he caused the generation of another 'branch' of humanity, so to speak.
However my main issue with this is based upon my intrinsic need for evidence (blame the archaeologist in me ok?).
However, what I feel is a very positive - and strong - thing about this view is that it gives the collective group a source, something in comon and a focus. A belief which can be shared and debated. Something every society has had since pre-history.
But basically from a species development perspective IM inclined to ignore it.
3. Defects
Another valid point made by AlexandiraC - a blind person - or anyone with some 'impairment' has a sensorary compensation. For example, partially sighted people (from birth) often develop heightened senses of touch, smell, taste or hearing. It doesn't mean they are defected it just means they are not 'inbalance'.
I feel, personally, that if you have a defect you sound like a broken sofa, or misshapen car which gets thrown in the reject pile. I refuse to accept that since a lack of understanding or tolerance does not represent that you, I or anyone else here has a defect
Sorry for waffling a bit XD