GMO vs hybrid, confusion and controversy
A lot of confusion surrounds the idea of GMO, or genetically modified organisms. The most common misconceptions involve confusion between hybridization of plants and genetic engineering.
A hybrid is created by breeding species of the same genus. This is called "conventional breeding" and it employs processes that occur in nature, such as sexual and asexual reproduction. The selected characteristics are not new for the species. Common plant hybrids are Leyland Cypress, peppermint, grapefruit and wheat. You might also picture dog/horse pedigree charts where certain traits are cross bred for specific outcomes. Or perhaps you picture the genetic selection chart from your high school biology or horticulture book, where you charted your family traits or even cross bred a flower.
By definition a GMO product has had its genome altered. This is called recombinant DNA technology. Genetic engineering works primarily through insertion of genetic material. Engineers must also insert a "promoter" gene from a virus to make the inserted gene express itself. This allows insertion of DNA from other genus.
When I teach GMO we always start with taxonomy so that students understand the division of kingdoms(1) and the classification of species(2) within each kingdom. We then look specifically at insect classification (animalia kingdom) to enforce the concept of classification and introduce identification of characteristics (ie:hard/soft bodies, two wings). Hybridization is studied when we identify and classify plant characteristics within the plantae kingdom. I introduce GMO last, after a lab where we extract DNA from a strawberry. GMO can take a gene from a bacteria and put it in a plant. Students then understand that the engineering crosses genus and even kingdoms. DNA "jumps" across the classification chart in opposition to evolution and adaptation.
Look at the chart below and think through the process of extracting Bt bacteria (monera) and introducing it into corn (plantae), a widely talked about GMO controversy. GMO corn contains a soil bacteria that kills the cutworm by "exploding" its intestines. We do not know how this affects humans or animals who eat the corn as feed. This is why many people are upset. There are many benefits to GMO, but there are also many controversies.
GMO products include medicine and vaccines as well as biopesticides and bioherbicides. Other benefits do include increased nutrients, yields and stress tolerance of crops and animals. Environmentally GMOs contribute to conservation of soil, water and energy and provide food security for growing populations.
HOWEVER, there are potential human health impacts including allergies, transfer of antibiotic resistance, and unknown health effects. A major environmental impact that we are already seeing is cross pollination contamination in crops and there are unknown effects on soil microbes and flora and fauna diversity.
Most of the controversy today revolves around intellectual property rights, ethics, labeling and right to know, and societal impact, as well as human health.
Studies indicate that almost all soybeans, corn, alfalfa, cotton and canola grown in the US is GMO. But the US does not require labeling so the average American does not know their food contains GMO. This is possibly the largest controversy, the right to know in a country that prides itself on citizen rights.
Keep in mind that all organisms are evolving and adapting. There are phenomenal examples in nature. I encourage you to seek out and watch Queen of Trees (Nature series). Once we alter a genome evolution and adaptation begins. This is a huge, irreversible, human impact on our environment that everyone should understand.
(1) Five-Kingdom System:
Animal Kingdom – Invertebrates (without backbones) and vertebrates (with backbones), multicellular, no cell walls, obtain energy through respiration
Plant Kingdom – multicellular, have cell walls, obtain energy through photosynthesis. Ex. mosses, ferns, flowering and seed plants
Fungi Kingdom – cells with cell walls but not green and do not carry out photosynthesis, break down other organic materials to obtain food. Ex. mushrooms and molds and yeasts
Protist Kingdom – come in a wide variety of forms, some are animal-like, such as amoeba, paramecium and protozoan. Some are plant-like such as algae and others are fungi-like. Many are single-celled and others are multicellular.
Monera Kingdom – some photosynthesize while others respire. The nucleus of moneran cells are not bounded by nuclear membranes like cells in the other kingdoms. Ex. bacteria and blue-green algae
(2)The classification of humans – Homo sapiens