For those who only know the movie, there is a scene to the end of the Second Jungle Book where the red dogs arrive; they are enemies of the wolves, who kill everything. Mowgli takes them on, and uses intelligence to make use of small things to beat them and nature to escape them, I won’t give it away to those who have not read it, but it is a lovely bit of problem solving. There is something similar in Gregor Mendel’s work, at least I see the similarity.
One of Darwin’s puzzles about the development of species was why a change wasn’t diluted as each generation mated with those that did not posses it. At the beginning of the twentieth century microscopes improved to the degree that it was possible to see pairs of chromosomes dividing and joining, and it became clear that there was a discrete unit of information from each parent, not a blending. Mendel had already demonstrated that pre-Darwin, but Darwin did not know of his work.
Mendel carefully selected peas and beans until he had varieties that bred pure, and then crossed them. For example he crossed a bean that was always dwarfed with one that always grew tall, or a wrinkled pea with a smooth pea. He discovered that the children of this cross displayed only one characteristic of the parents, they might have been all tall for example. However, when he then bred these offspring together he found one in four of their children grew dwarf again. Of course he had not heard of genes, the word was not invented, but he concluded that each individual carried a pair of ‘sex factors’ and was passing one as a discrete ‘sex factor’ to the offspring.
It is quite a jump, but if you think of one parent with two Gianting genes and one with two dwarfing genes their offspring will get one of each gene.
Now consider if you cross these ‘children’ that carry one of each gene and they each pass one gene, on average you will get one with two dwarfing genes, two with one of each gene, and one with two Giant genes. However the Giant gene is ‘dominant’, that means it is the gene that shows in the actual plant, only the one with two dwarfing genes comes out dwarf.
The similarity with Mowgli? Well they both solved complex problems using available, natural resources. I suppose Mendel covered his flowers with little muslin bags and used a paint brush to pollinate only from a known source, but that is pretty minimal technology. I won’t hold it against him, compared to tearing cells apart, staining them, and putting them under a microscope it is minimal.
Biologists call that first generation, with one of each gene, the F1 generation, the next one is the F2. When you buy seeds that are an ‘F1 hybrid’ that is what it means. People tell me that I mustn’t save seed from them, ‘It will be no good’. Well, that is not how I read it, half of them will be like their parents, and a quarter will be like each grandparent. To me that means that half will be great, and, as nobody would bother hybridising rubbish, the other half will be pretty good.
I am a great one for saving seed, if you save seed from the best of things it is not long before you have selected for a plant ideally suited to your location and soil. Someone did a study recently of exotic vegetables imported by immigrants and grown on allotments, they were consistently much better than seed of the same species supplied by a commercial seedsman. Natural selection takes generations, but by being selective yourself you introduce the ‘intelligent design’ element that is lacking in nature; play ‘God’ for a few years and you can have the best runner beans ever.