[jcon40]

I have heard the question but never a good answer put to evolutionists where;

If we only use 5-10% of our brain

and if the demands made on an organizism by its environment is what causes organisms to evolve

how did we ever need or use 100% of or brain at sometime in the past?

[qam1]

If we only use 5-10% of our brain

THis is a myth. We use all of our brains

http://en.wikipedia.org/wiki/10%25_of_brain_myth

Or just type 10% brain myth in any search engine for more