​Invasive species, in general, grow very well in a new area that they invade and often outcompete native species. An explanation for the better growth and propagation of invasive species in comparison to their native counterparts is provided by which one of the following hypotheses?​

Correct option is C

The Enemy Release Hypothesis (ERH) suggests that invasive species thrive in new environments because they escape their natural predators, pathogens, and competitors that controlled their population in their native habitat. This absence of natural enemies allows invasive species to grow faster, spread widely, and outcompete native species.

Key Points of the Enemy Release Hypothesis:

1. Lack of Natural Predators – Native species are regulated by natural enemies (e.g., herbivores, pathogens), but invasive species often escape these pressures.
2. Reduced Competition – In their new environment, invasive species may face less competition for resources, giving them an advantage.
3. Greater Resource Allocation to Growth – Without predation, more energy is invested in growth and reproduction rather than defense mechanisms.
4. Example:
   • Lantana camara: Invasive in India, spreads rapidly due to the absence of herbivores that feed on it in its native range.
   • Water hyacinth (Eichhornia crassipes): Grows aggressively in freshwater ecosystems outside its native South America because of the lack of natural insect herbivores.

Information Booster

1. Invasive Species – Organisms that establish and spread rapidly in non-native environments, often disrupting ecosystems.
2. Impact on Native Species – Can cause biodiversity loss, habitat modification, and economic damage.
3. Control Measures – Biological control, habitat restoration, and mechanical removal of invasive species.
4. Other Hypotheses Related to Invasion Success:
   • Evolution of Increased Competitive Ability (EICA) Hypothesis – Invasive species evolve reduced defense mechanisms and allocate resources to rapid growth.
   • Novel Weapons Hypothesis – Invasive species introduce chemical defenses that native species are not adapted to (e.g., allelopathic chemicals).
5. Management Strategies – Preventing introductions, monitoring ecosystems, and introducing natural enemies to control invasive species.

Additional Information

• Option (1) Ecological Niche Hypothesis (Incorrect):

  • This explains how species coexist by occupying different niches, but does not specifically explain why invasive species dominate new environments.

• Option (2) Intermediate Disturbance Hypothesis (Incorrect):

  • This states that moderate levels of disturbance promote biodiversity, but it does not explain the success of invasive species.

• Option (4) Biotic Resistance Hypothesis (Incorrect):

  • This suggests that native species and ecosystems resist invasions, but many invasive species overcome these resistances due to the lack of natural enemies.