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.
Saying something is âjust a theoryâ is a laypersonâs term that has no relationship to science. To most people a theory is a hunch. In science a theory is the framework for observations and facts, Jaime Tanner, a professor of biology at Marlboro College, told Live Science.