Question

How is natural selection a major mechanism of evolution?

Answer 1

Natural selection as a major mechanism of evolution:

1. Natural selection is the mechanism via which populations of living organisms adapt and change.
2. Individuals in a population are naturally variable which means that they are all different in some ways.
3. This variety means that some individuals have traits better suited to the environment than others.
4. Natural selection causes differential survival and reproduction capacity of organisms due to variations in their phenotype.
5. It occurs when the populations of the organisms are subjected to the environment.
6. An example of natural selection is the origin of giraffes' long necks.
7. The ancestors of modern giraffes were animals similar to deer or antelope, with necks of ordinary length.
8. One another example of recent natural selection in humans involves that the ability to tolerate the sugar, and lactose, in milk.
9. Adults are unable to drink milk because their body switches off the intestinal production of lactase which is an enzyme that digests the sugar in the milk, after weaning.
10. Due to problems in digesting milk, they suffer symptoms including bloating, vomiting, diarrhea, etc.