Being the only child is a unique position in a family. Without any siblings to compete with, the only child monopolizes his parents' attention and resources, not just for a short period of time like a firstborn, but forever.
Like gravity and plate tectonics, evolution is a scientific theory. In science, a theory is the most logical explanation for how a natural phenomenon works. It is well tested and supported by abundant evidence. It means quite the opposite from our informal use of the word theory, which implies an untested opinion or guess. As a scientific theory, evolution enables scientists to make predictions and drives investigations that lead to new kinds of observable evidence.
Scientists are people study things and try to figure out patterns or rules to explain how they work. Scientists might study things like the ocean and its creatures, volcanoes, or machines. They try to. identify scientific laws or processes that can be observed over and over and then explain why the.