The basic unit of life is the cell
I think the answer you are looking for is calorie with a lowercase "c". However the substance should be water.
It was the trip that Charles Darwin went on in attempt to find the answer of how animals got on earth in the first place and how they changed over time. This later on helped him discover evolution and natural selection. The most significant find on this voyage was that he found that different types of finches evolved to the food around them. Smaller beaks meant the finch ate more small nutrients but larger beaks meant the finch ate more harder prey such as fish and worms.