Consider the following statements: Statement-I: Invasive species can outcompete native species. Statement-II: Invasive species ar…

Question

Consider the following statements: Statement-I: Invasive species can outcompete native species. Statement-II: Invasive species are always harmful to ecosystems. Which one of the following is correct in respect of the above statements?

1. A. Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
2. B. Both Statement-I and Statement-II are correct and Statement-II does not explain Statement-I
3. C. Statement-I is correct, but Statement-II is incorrect (Correct answer)
4. D. Statement-I is incorrect, but Statement-II is correct

Correct Answer

Option C — Statement-I is correct, but Statement-II is incorrect

Detailed Solution & Explanation

The correct answer is Statement-I is correct, but Statement-II is incorrect.

Key Points

• Statement-I is correct. Invasive alien species frequently outcompete native species for space, light, nutrients and water. Released from the predators, parasites and pathogens that regulated them in their native range, they can grow and reproduce unchecked — the enemy release hypothesis.
• Statement-II is incorrect because of the word "always". Not every introduced species becomes harmful. Many introduced species never establish, many establish without spreading, and a number are economically valuable — most of India's plantation crops and several staple food crops are introductions. A species is called invasive only when it establishes, spreads and causes ecological or economic damage.
• Absolute qualifiers — *always, never, all, only* — are the standard weak point of a statement, and here they are exactly what makes Statement-II fail.

Additional Information

• Invasive alien species are among the leading drivers of biodiversity loss, ranking with habitat destruction, overexploitation, pollution and climate change. On islands, where native species evolved without competitors or predators, they are often the single greatest cause of extinction.
• Major invasive species in India:
  • *Lantana camara* — introduced as an ornamental, now smothering forest understoreys across much of the country
  • *Parthenium hysterophorus* (congress grass) — arrived with imported wheat in the 1950s, causes dermatitis and allergic rhinitis
  • *Eichhornia crassipes* (water hyacinth), the "Bengal terror" — chokes waterbodies and depletes dissolved oxygen
  • *Prosopis juliflora* — planted for fuelwood in dry regions, now displacing native scrub
  • African catfish, tilapia and the red-eared slider turtle in freshwater systems
• The Convention on Biological Diversity, Article 8(h) requires parties to prevent the introduction of, control or eradicate alien species that threaten ecosystems, habitats or species. Target 6 of the Kunming-Montreal Global Biodiversity Framework addresses invasive species directly.
• The Wild Life (Protection) Amendment Act, 2022 for the first time gave India a statutory framework for regulating invasive alien species, empowering the Centre to regulate or prohibit their import, trade, possession and proliferation.