Relevance for UPSC: GS Paper 3 – Science & Technology (Genetics, Evolution, and Ecology)

A Puzzling Discovery

In a remarkable breakthrough, scientists have discovered that the ant species Messor ibericus can produce male offspring (drones) belonging to two different species — its own and another closely related species, Messor structor.
This is the first recorded instance in the animal kingdom where a single queen produces males of two species, challenging long-held ideas about reproductive boundaries in nature.

The Genetic Twist

Normally, drones are born from unfertilised eggs and thus contain only the mother’s genetic material. However, in Messor ibericus, some drones were found to carry the genetic signature of Messor structor.

Scientists suspect this might have resulted from ancient hybridisation between the two species. Over generations, Messor ibericus may have evolved caste-biasing genes — genetic factors that decide whether female larvae become queens or workers.

By producing Messor structor-type drones, the colony may be generating hybrid offspring that bypass caste restrictions and help maintain a balanced workforce — a rare example of nature “rewriting” its own genetic code for survival.

Why It Matters

This discovery offers new insights into evolutionary genetics, hybridisation, and social insect behaviour.
It shows how hybridisation — once thought to weaken species — can actually promote adaptability and evolutionary resilience. Such findings deepen our understanding of how life evolves complex survival strategies, even at the smallest scale of an ant colony.

Key Concepts

• Drones: Male ants produced from unfertilised eggs; they mate with queens.
  
• Hybridisation: Mixing of two different species to produce hybrid offspring.
  
• Caste-biasing genes: Genetic elements influencing whether an ant larva becomes a worker or queen.
  
• Speciation: The formation of new species through genetic divergence.
  
• Evolutionary resilience: The ability of organisms to adapt and survive changing conditions.
  

One-line Wrap:

Even the tiniest creatures prove that evolution has endless ways of surprising us.

UPSC Prelims Question:

Recently, scientists discovered that Messor ibericus ants can produce drones of two species. What explains this phenomenon?
(a) Cloning of the queen’s genetic material
(b) Hybridisation leading to cross-species offspring
(c) Asexual reproduction through budding
(d) Symbiotic fusion with another colony
Answer: (b)