Why is variation beneficial to the species but not necessarily for the individual?

Explanation

Variations are beneficial to the - species than individuals because sometimes for a species, the environmental conditions change so drastically that their survival becomes difficult. For example, if the temperature of water increases suddenly by global wanning, then most of the bacteria living in that water would die as they cannot adapt to that excessive heat. Only a few variants that have ,resistance to heat would be able to survive. However, if these variants Were not there, then the entire species of bacteria would have been destroyed. Thus, these variants help in the survival of the species. However variations are not necessarily beneficial for the individuals . organisms.