"Variations that confer an advantage to an individual organism only will survive in a population." Justify.
Useful variations give advantage to individuals in obtaining more food, adaptation to environmental changes and higher success in the struggle for existence. They give benefit in survival and reproduction. Differential reproduction increases the useful variations in the populations. Other individuals with harmful variations will be eliminated. For example, some bacteria have ability to tolerate high temperature. In warm environment non-tolerant bacteria will be killed. Others with tolerance to high temperature will survive and multiply.