Industrial melanism:
• In England, before industrialisation, white-winged moths were more in number than darkwinged moths.
• But after industrialisation, dark-winged moths became more in number than whitewinged moths.
• This is because during industrialisation, the tree trunks covered by white lichens became dark due to deposition of dust and coal particles.
• As a result, white-winged moths could be easily picked up by predators from the dark background and dark-winged moths survived .
Chemical resistance:
• Excessive use of herbicides and pesticides has resulted in evolution of resistant varieties of microbes in much lesser time scale.
• As a result, pathogenic bacteria are appearing in very short period.
