What is the species name for humans

What came first egg or chicken? and is tomato a vegetable or a fruit?

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere

Under which of the following circumstances would natural selection not operate on an organism