To understand how modern breeding works let's go back and use our tomato as an example. Let's say we have the cultivated tomato which is big and juicy but it's very susceptible to something say a virus. Where as the wild tomato has no taste whatsoever, it's poisonous, but it's resistant to the virus. What the plant breeder can do is cross the cultivated tomato with the wild tomato to get an F1 hybrid. Now this F1 hybrid is exactly a cross. Half cultivated, half wild. And we can see that it's intermediate in size and intermediate in color. Genetically what's happening is if we have the genome of the cultivated tomato, which it would show here for example as a library of red books. And the genome of the wild tomato, which we'll call here of a library of white books. When we mix the two, we'll get a library that's partially red and partially white, 50, 50 according to Mendelian genetics. And now what the breeder will do, will take the F1 hybrid, the first generation hybrid, they cross it back to the cultivated tomato, to the red tomato. And then over generations, you can get various traits transferred from the wild tomato into the cultivated tomato. Genetically what we're doing now is we're increasing the amount of red books, the amount of red pages in the genome, so that in the end, we will have the gene for virus resistance, which came from the wild tomato, from the from the white library. Mixed into the predominantly red library, the red genome, which came from the cultivated tomato. The problem comes that this is an inexact science at best. And the reason is that while we have selected for the gene for virus resistance, we may also have inadvertently selected for a gene, for example, for bad taste. And so we have bad traits coming form the wild tomato together with the good traits. So the question is is there a way that I can take just the trait that I want? Just the trait for virus resistance from the wild tomato and put that into the cultivated tomato? Exactly one gene for one trait while leaving the good background of the cultivated tomato. And that we can do through genetic engineering. That's exactly the goal with recombinant DNA methodology. I don't wanna even take one book from the wild tomato. I wanna take one-half of one page. And slip this in to the red library. Slip this one gene into the genome of the cultivated tomato. That way I have a cultivated tomato which still maintains all of its traits such as size and color and taste, but is now resistant to the virus. So what have we done here? We've taken a specific gene from a wild tomato, the gene for virus resistance, placed this gene inside the genome of the cultivated tomato. In classic breeding this can be accomplished over several generations, which means several years. But with also the transfer of deleterious genes as well. In genetic engineering we do this in a targeted relatively exact manor only the gene of choice is transferred and in one generation