Fiddling with science

"Although man does not cause variability and cannot even prevent it, he can select, preserve, and accumulate the variations given to him by the hand of nature almost in any way which he chooses; and thus he can certainly produce a great result" - Charles Darwin.

Charles Darwin is a hero of mine, not for his most obvious work on natural selection and survival of the fittest, but for his smaller experiments, his potting-shed projects and back-lawn experiments. He is famously known as the naturalist on-board the Beagle, charting various stretches of the coast of South America. But some of his most interesting work was done when he was back on dryland, experimenting, dissecting, and making observations in the meadows and woodlands surrounding his home at Down House.

Darwin tinkered with his science. He played music to earthworms to understand whether they could ''hear'' and played with his venus fly-traps in the conservatory to understand what triggered the traps to snap shut. He soaked different seeds in sea-water to see which could be dispersed on oceanic currents from mainland to islands. He floated a dead-pigeon in salt water for thirty days to see whether seeds from the pigeon's crop would germinate [they did]. He spent eight years fiddling about with barnacles, and wrote a book on barnacle taxonomy. He got into pigeon breeding and had sixteen different breeds at the height of his hobby. He was genuinely curious about the natural world.

Knowledge about Darwin's little experiments has prompted me to try something at home in my back-garden - How quickly can selective breeding bring about change in fruit size in poroporo?

Some thoughts I have had in the past week:
1. The birds are eating all my strawberries at the moment, before they are fully ripe and the boys get to them.   Will the birds leave my fruiting poroporo alone, or do I need bird-netting to keep them off?
2. If I don't use bird-netting, will the entire shire of Karori be covered in poroporo seedlings in the next few years, dispersed by birds from my back garden?!
3. Will the natural pollinators cross-pollinate my experimental plants with those in the wild, and mute any breeding effort to increase fruit size?
4. Will the fruit end up so large that birds can no longer disperse them?
5. And perhaps most importantly, will poroporo jam taste any good?