By himself, Adam was incapable of doing his job, incapable of either filling the earth or subduing it. So God created a helper suitable for the job. Woman was not an afterthought, or just someone for Adam to talk to, or someone who would make him sandwiches while he did all the filling and subduing of the earth. She was essential to the entire program. When God gave Eve to Adam, He was handing Adam an amplifier. Adam alone is just Adam. Adam with Eve . . . becomes the human race.