yes, can you duplicate products, but when you do you are creating a new product.
To duplicate a product, go to admin > products, and under the Manage drop down select copy.
You will now have a new product that is an exact copy of the original which you can modify as required. The product you copy becomes a custom product that is not linked to a smart-select catalog and will no longer receive any updates that are pushed to the original product so that is something you need to be mindful of.
I hope that helps, if you need more detailed information please contacft client servies via the ? button in the top blue bar of your admin settings screen.