By studying fossils, scientists can learn how much (or how little) organisms have changed as life developed on Earth. There are gaps in the fossil record because many early forms of life were soft-bodied, which means that they have left few traces behind. This is why scientists cannot be certain about how life began.
Alcoholic fermentation; carbon dioxide. Alcoholic fermentation produces alcohol and carbon dioxide in bread. The alcohol evaporates during the baking process.
Survival of the fittest. If one organism thrives better in an enviornment and the other organism struggles, the one that is more adapted will obviously play a part in helping the less adapted organism die out. Food is a major point along with other aspects