Make sure you post the picture of the tree, so I can answer.
Answer:
The process by which organisms that are better suited to their environment than others produce more offspring. As a result of natural selection, the proportion of organisms in a species with characteristics that are adaptive to a given environment increases with each generation.
Explanation:
I think what they rely on is there experiment and how they do it
Boys shoulders broaden and voice deepen, Girls start having menstrual periods and develop breast. <span />
