From this one migrant species would come many -- at least 13 species of finch evolving from the single ancestor.
This process in which one species gives rise to multiple species that exploit different niches is called adaptive radiation. The ecological niches exert the selection pressures that push the populations in various directions. On various islands, finch species have become adapted for different diets: seeds, insects, flowers, the blood of seabirds, and leaves.
The ancestral finch was a ground-dwelling, seed-eating finch. After the burst of speciation in the Galapagos, a total of 14 species would exist: three species of ground-dwelling seed-eaters; three others living on cactuses and eating seeds; one living in trees and eating seeds; and 7 species of tree-dwelling insect-eaters.
Scientists long after Darwin spent years trying to understand the process that had created so many types of finches that differed mainly in the size and shape of their beaks.
C...the key is that they are photosynthetic...so they produce oxygen (like plants)!
IT IS NOT POSSIBLE to produce malleable cast iron in pieces having large cross sectional dimension. This is because, iron has a very rapid cooling rate and it will not be possible to achieve this rate at different cross sectional areas in a sheet of iron.
Answer: Mixture
Explanation:
If there is and unstable element composition of say, pure graphite an un-pure gold then a chemical reaction will most likely be used to separate the two elements.