Are you saying scientists have found the missing link and solved the mystery of evolution once and for all?
I pretty sure they have not. Just a few months ago they found a human skull that dated back to 1.8 million years ago that basically turned the classification of human species upside down.
http://www.cnn.com/2013/10/17/world/europe/ancient-skull-human-evolution/
Just like pretty much all scientific theories a new discovery can come completely debunk a theory widely considered as scientific truth.
Of course things like gravity, motion, modern medical science etc ARE known in great detail.
But things like the beginning of the universe, the origins of man, etc are things that they dont know and may never know.
I respect their quest for knowledge, but when they say things like they know how many protons are in the universe thats where I stop believing anything they say.