What are the different ways in which individuals with a particular trait may increase in a population?

Q. What are the different ways in which individuals with a particular trait may increase in a population? 

 

Answer:- 

The different ways in which individuals with a particular trait may increase in a population, are :
(i) By natural selection – Organisms with a particular trait may be naturally selected because it provided a survival advantage. That particular trait may thus increase in the population. It may direct evolution of species population by adaptations to fit their environment better.
(ii) Genetic drift & inheritance – An accident in small populations may result in surviving of organisms with a particular variant only. This can increase the frequency of some genes in that population, even if they give no survival advantage. This is the notion of genetic drift, which provides diversity without any adaptations.