Millions more are scheduled for release over the next decade. As engineered organisms scatter worldwide, destructive breakouts are ever more likely. Their strategic advantages, designed right in, may include immunity to the herbicides needed to control them. Others germinate earlier, tolerate cold better, or produce their own insecticide. This means that engineered genes in domestic species could spread to native populations and permanently alter their genetic makeup.
Hybrids carrying engineered genes can erode diversity or destroy it entirely.
Such irreversible effects from short-term commercial decisions would be catastrophic. Creating resistant pests For years, organic farmers have sprayed their crops with a natural toxin called Bt, which breaks down rapidly in sunlight, thereby causing no permanent damage. Now, however, biotech companies have inserted Bt genes directly into certain plants. The plant itself becomes a permanent pesticide. The negative outcome is that insects are exposed to Bt over long periods, eventually developing resistance to it.