Biology · Evolution · NEET
It is both. The underlying mechanism is natural selection: resistant variants already exist in the population by chance mutation. It is called anthropogenic (human-caused) because the selection pressure — the antibiotic or pesticide — is applied by humans. So it is natural selection driven by human action.
No. This is the most tested idea. The mutation for resistance is pre-existing and random. The antibiotic does not induce it. The drug only kills the non-resistant (sensitive) cells, so the few resistant cells survive and multiply. Believing the drug 'creates' resistance is a Lamarckian error; the correct view is Darwinian selection of a pre-existing variant.
NCERT lists man-made dog breeds under evolution by anthropogenic action, so both involve human action. The usual distinction: artificial selection (domestication) is humans deliberately breeding for desired traits. Anthropogenic resistance is an unintended by-product of humans applying chemicals. In NEET matching questions, both weeds/microbes and man-created dog breeds are accepted as anthropogenic action.
Four accepted examples: herbicide-resistant weeds, pesticide/insecticide-resistant insects, drug/antibiotic-resistant microbes and drug-resistant eukaryotic cells (like cancer cells), and man-created breeds of domesticated animals such as dogs. Darwin's finches are NOT anthropogenic — they evolved naturally by adaptive radiation.
Microbes and insects have very short generation times and huge population sizes, so a helpful mutation can spread through many generations quickly. Constant chemical pressure removes sensitive individuals every generation, sharply raising the frequency of resistant alleles in a few years — much faster than slow natural evolution.
Which of the following refer to correct example(s) of organisms which have evolved due to changes in environment brought about by anthropogenic action? (a) Darwin's Finches of Galapagos islands (b) Herbicide resistant weeds (c) Drug resistant eukaryotes (d) Man-created breeds of domesticated animals like dogs
Match List I with List II. List I | List II (a) Adaptive radiation | (i) Selection of resistant varieties due to excessive use of herbicides and pesticides (b) Convergent evolution | (ii) Bones of forelimbs in Man and Whale (c) Divergent evolution | (iii) Wings of butterfly and birds (d) Evolution by anthropogenic action | (iv) Darwin Finches Choose the correct answer from the options given below
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Yes. It is treated as direct evidence of evolution happening within our own lifetime. It shows the same steps as natural selection — pre-existing variation, selection pressure, differential survival — just occurring in a short time because humans apply the pressure.
Yes, the mechanism is identical. Resistant variants already exist; the pesticide or antibiotic removes the sensitive ones, leaving resistant ones to reproduce. Only the chemical and the organism differ.
It is a high-yield 1-mark topic that appears as example-matching and 'which is/is not anthropogenic' questions (2020, 2021). Knowing which examples count and that Darwin's finches do NOT count usually secures the mark.
Yes. Insects becoming resistant to DDT and other pesticides after repeated spraying is a classic case of pesticide resistance evolving by anthropogenic action.
