So, the Sun's light takes about 8.3 minutes to reach us. This means that we always see the Sun as it was about 8.3 minutes ago. ... The nearest large galaxy to us, Andromeda, is 2.5 million light-years away. So, we see Andromeda as it was 2.5 million years in the past.
When we talk about evolution we come across the process of natural selection. Genetic variation is always required for the natural selection. A change or variation in the genes may help the individuals in a population to better adapt to the environment. Such changes may be brought by mutations or random mating in the population. Such variations help in the survival of the population by allowing them to adapt to changing environmental conditions.