Answer: Natural selection can be defined as the differential survival and reproduction of members of the population of a species that have suitable traits to survive in a population of species.
Explanation:
The punctuated changes in the population of species have been found inordinately faster in the geological time scale, but changes per-generation have been relatively slow. Also, the rate of evolution in such a population is also slow. The punctuated changes in the population are because of evolution but the per-generation changes are the outcomes of the natural selection, in which only the beneficial traits are passed from one generation to another.
Viruses need to be inside a living thing (of course the living thing has to have the right temperature which most living things do) . When they're inside a living thing they start injecting the host's cells with its DNA in order to make more copies of itself which allows the virus to spread. So basically viruses need to be inside something living.
