Here is a very nice little video that in less than nine minutes provides a wonderfully accessible introduction to the concept of evolution.  Young science students might find in particularly helpful.  It’s short, presents the consensus view and my be useful even for adults for whom the term “evolution” has unnecessarily sinister connotations.

Here are two others that go on to talk about “genes” & “DNA.”  Both are directly to the point and helpful for anyone new to either concept.

Thanks to a great site called Stated Clearly.  Hope they create a lot more of these.