Because natural selection can only increase or decrease frequency of alleles that already exist in the population
Just as the organs in an organ system work together to accomplish their task, so the different organ systems also cooperate to keep the body running. For example, the respiratory system and the circulatory system work closely together to deliver oxygen to cells and to get rid of the carbon dioxide the cells produce.
Answer:
4
Explanation:
Science is fun but isn't the greatest thing
I hope you have a amazing week to and only good things happen to you!!!!
I would say Calcite im i right?
