Short answer type question
How does genetic diversity affect the sustenance of a species?
Genetic diversity includes variation within a population and diversity between populations that are associated with adaptation to local conditions.
Genetic variations (e.g. allelic genes) lead to individual differences within species. Such variations eventually lead to evolution. They also improve the chances of continuation of species in the changing environmental conditions or allow the best adapted to survive.
The greater the genetic diversity, the better would be the sustenance of a species.
a. Existence of subspecies or races
b. There are about 1000 varieties of mangoes and 50,000 varieties of rice or wheat in India.
c. A medicinal plant Rauwolfia vomitoria which secretes active component reserpine is found in different Himalayan ranges. This plant shows variations in terms of potency and concentration of the active chemical, from location to location.