A new study published in Nature has reported a rare and surprising biological phenomenon: queens of the Mediterranean harvester ant species Messor ibericus can give birth to male offspring of an entirely different species, Messor structor. 

The Discovery

• Research team: Conducted by international scientists from France, Italy, Bulgaria, and Austria.
  
• Key finding: While Messor ibericus queens produce normal hybrid worker ants (with genetic material from both ibericus and structor), their male offspring are pure Messor structor.
• Context: In harvester ant colonies:
  • Queens produce eggs,
  • Male drones provide sperm,
  • Sterile female workers perform tasks like nest building and brood care.
• Anomaly noticed: All Messor ibericus workers were hybrids, with ~50% of their DNA from Messor structor. This hinted at an unusual reproductive mechanism.

Significance of the Finding

• Evolutionary biology: This is one of the few known cases where a living organism produces offspring of another species naturally, raising questions about reproductive isolation and species boundaries.
• Genetic studies: It provides a new model to study hybridization, speciation, and the role of unusual reproductive strategies in evolutionary survival.
• Ecological perspective: Such mechanisms may give ants adaptive advantages in colony survival, workforce efficiency, and environmental resilience.

One-Line Wrap

The Messor ibericus ant queens’ ability to give birth to males of another species, Messor structor, is a rare evolutionary exception that blurs traditional species boundaries and opens new avenues in genetics and evolutionary biology research.

Q. Consider the following statements regarding the Mediterranean harvester ant Messor ibericus:

1. Queens of Messor ibericus can produce male offspring of another species, Messor structor.
2. The worker ants in Messor ibericus colonies are hybrids, carrying DNA from both Messor ibericus and Messor structor.
3. The discovery challenges the long-held biological principle that offspring always belong to the same species as their parent(s).

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: (d)