While the rise of genetic engineering has created crop species that can withstand droughts, pests, and other challenges, there has been an intense backlash against their use. Many people believe that the research on the long-term impacts of GMO food is incomplete and that they contribute to health problems like allergies. Others worry that the altered genes will make their way into wild plant populations and permanently change the ways they work for the worse.The Demeter certification has a zero tolerance for genetic modification (GM) in agriculture, gardening, packaging (compostable packaging can be made with GMO crops). Demeter standards also forbid the use of any GM organisms and ingredients, including animal feeds.