What is biological magnification? Explain how DDT as a water pollutant undergoes biological magnification.and Species facing competition might evolve mechanism that promotes coexistence rather than exclusion. Justify this statement in light of Gauss’ competitive exclusion principle, citing a suitable example.
Answers
Explanation:
Biological magnification refers to increase in concentration of toxic substances at successive trophic levels. DDT undergoes biomagnifications when it gets washed away from the fields and enter the water bodies. Example when DDT enters a water body in 0.003ppm undergoes biological magnification as it passes through different trophic levels.
Gause’s ‘Competitive Exclusion principle’ states that two closely related species competing for the same resources cannot co exist indefinitely and the competitively inferior one will be eliminated eventually.” This may be true when resources are limiting and not otherwise. If two species compete for the same resource, they would avoid competition by choosing for instance different times for feeding or different foraging patterns. It has been seen that five closely related species of Warblers ,living on the same tree were able to avoid competition and co exist due to behavioural differences in their foraging activities. From this we can substantiate that species facing competition might evolve mechanism that promotes coexistence rather than exclusion.