Question

Anthropogenic action can hasten evolution. Explain with the help of a suitable example.

Answer 1

A)

Anthropogenic actions, i.e. human activities have been found to hasten evolution. Resistant organisms / cells are appearing in a time scale of months or years and not centuries. Example to illustrate this: Use of DDT has resulted in evolution of DDT-resistant mosquitoes. When DDT was used for the first time, many mosquitoes died, but a few survived. These few mosquitoes showed resistance to DDT and reproduced in the presence of DDT. Most of the offspring were also resistant to DDT. Hence, the mosquito populations of today consist mainly of DDT-resistant mosquitoes and hence, DDT is not effective. In the absence of DDT, these DDT-resistant mosquitoes had no advantage over those mosquitoes, which were sensitive to DDT.