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12th Biology 2013 Set1 Delhi Board Paper Solution

Question 20

With the help of any two suitable examples explain the effect of anthropogenic actions on organic evolution.

Effect of anthropogenic actions on organic evolutions.
(i) Industial melanism: It was due to smoke and soot coming out of man made industries which caused a shift from white-winged moths on trees to dark winged or melanised moths.
Prior to industrialisation white coloured lichens covered the bark of trees which was favourable for white winged moths.
(ii) Use of herbicides and pesticides has resulted in selection of resistant varieties in very short time scale. Also development of microbes resistant to antibiotics in period of months is due to anthropogenic actions.