Question -
Answer -
An individual attribute could increase in a population within the following 2 ways:-
(a) Natural selection: if an attribute is useful to a population, it’ll increase naturally.
For example – mosquitoes which are resilient against a particular pesticide will pass on its genes, so that future generations become resistant as well. The mosquitoes which are affected by the pesticide die out.
(b) Genetic drift: if a species faces a catastrophic event where most of the population is wiped out, the surviving population can pass on their traits to the following generations. This may result in a rise of the attribute within the population.