I asked this question on Twitter responding to a Mother Earth News comment and didn't receive any responses.
So, I found and read a USDA white paper on Executive Order (E.O.) 13112, Invasive Species, dtd.Feb 3, 1999 (link #1 below) along with the actual EO document and read an interesting definition. E.O.13112 defines an invasive species as “an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.”.
The USDA white paper specifically lists "Altered Business"as an example of harm while the EO lists the full definitions used on page one of source#2 below.
To start the discussion I'll list my humble opinions:
A. GMO are not a natural propgation, (man-made origin). GMO crops are therefore not native to any ecosystem.
B. Farmers being sued and taken over by business growing GMO crops that contaminated or "invaded" the non-GMO crop are examples of altered business opportunities.
C. Decrease in beneficial insects and increase in weed resistance are environmental impacts and
D. Likely human health impact is still unknown, therefore should be considered harmful until proven otherwise.
Following the definition of harm coupled with the populous surge against GMOs, the question is something to mull over with your morning coffee and of course add to this discussion.
USDA White Paper http://www.invasivespeciesinfo.gov/laws/execorder.shtml
E.O. 13112. Invasive Species. http://www.gpo.gov/fdsys/pkg/FR-1999-02-08/pdf/99-3184.pdf