Describe how the use of glyphosate use has created weeds that are resistant to it?
This is the same as bacteria and antibiotics. Let's say you have a field full of weeds and you spray it with glyphosate. Let's say it's not enough to kill everything, maybe 5-10% of the plants survive. Now you let those plants grow back and fill the field again in a year or two. This new crop of weeds is descended from those few plants that had a natural resistance to glyphosate. So now you need to use a lot more glyphosate to kill them. Let's say that again you kill 95% of the weeds and they grow back again. Now you need MUCH more glyphosate to do the same job. In a few generations, glyphosate becomes effectively useless. We are doing the same thing with antibiotics these days. We're overusing them and as a result we're growing antibiotic-resistant bacteria. So we need to always develop new antibiotics. And in a foreseeable future antibiotics will be totally useless and we might see horrible pandemics of diseases coming back, like tuberculosis and bubonic plague!