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

Individuals with a particular trait may increase in a population as a result of the following:
(i) Natural selection: When that trait offers some survival advantage.
(ii) Genetic drift: When some genes governing that trait become common in a population.
(iii) When that trait gets acquired during the individual’s lifetime.

1. Natural selection,

2. Genetic drift.

There are two ways in which individuals with a particular trait can increase in a population.

They are : 1. Natural selection: Here the organisms which have a particular trait that enhances the survival rate or provides a survival benefit are selected naturally over others.2. Genetic drift: This occurs in a small population where an accident or a chance event can change the frequency of genes, thus increasing a particular trait in a population, even if it provides no survival advantage.

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 provides a survival advantage. That particular trait may thus increase in the population. If may direct evolution of species population by adaptations to fit their environment better. 

ii. Genetic drift and inheritance: 

An accident is 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. 

iii. By mutation: 

iv. Geographical isolation: 

It leads to change in gene frequency leading to expression of one type of traits in a geographically isolated population 

v. Migration: 

It leads to flow of a particular type of gene in a specified population.