<<Disclaimer: Verify this information before applying it to your situation.>>
 
For up-to-date information on biotechnology and it's use in agriculture, I
suggest the International Food Information Council's Foundation web site
(http://www.ificinfo.health.org).  Check out both the consumer information
and the information for media and professionals.  They have very complete
information on the transfer of genetic material (which is not the same as a
protein) and how that is used to increase desirable factors in production of
food crops.
 
Genetic engineering has been used for a LONG time, it's just that now the
scientists have tools that can be used to manipulate smaller pieces of
genetic materials.  By increasing resistance to a herbicide, Monsanto was
probably increasing the availability of soil nutrients to the soybean plants
rather than the weeds (which the Round-Up would kill along with the soybean
plants if they weren't resistant).