oxygen. 99% of your body is composed of oxygen, nitrogen, hydrogen, calcium. 85% of your body is composed with other elements. I hope that helps!!!
I would say either 2 or 4, but 4 is more likely. New mutations can cause the finch to be able to eat larger seeds, or it can cause it to not be able to eat large things. The environment can also be a big factor. Finches living in the trees are closer to the seeds and the finches living in the logs are closer to the insects.
Hope this is clear enough.
