Given below are mechanisms that can facilitate major evolutionary transitions, such as the transition from genes to genomes, from unicellular to multicellular organisms, or from individuals to colonies.
A. Conflict mediation mechanisms maintain cooperation within emergent units.
B. Reduced genetic relatedness among cooperating units accelerates these transitions.
C. Division of labour evolves when specialisation increases group-level fitness more than individual fitness losses.
D. Transitions are irreversible once higher-level individuality is achieved.
Which of the following options is a combination of all correct statements?
Options:

Correct option is C

Correct Answer
(c) A and C only
Explanation
Major evolutionary transitions require mechanisms that reduce conflict and enhance cooperation at a higher level of biological organization. Statement A is correct because conflict mediation (such as policing or regulation) maintains cooperation within emerging higher-level units. Statement C is correct because division of labour is favoured when the increase in group-level fitness outweighs the loss in individual fitness. Statement B is incorrect because higher, not reduced, genetic relatedness promotes cooperation and facilitates transitions. Statement D is incorrect because evolutionary transitions are not always irreversible; breakdowns or reversals can occur under certain conditions.
Information Booster
• Major evolutionary transitions involve shifts in the level of selection
• Cooperation must be stabilized for higher-level units to persist
• Division of labour is a key feature of complex biological systems
• Genetic relatedness supports the evolution of cooperation
Additional Knowledge
Option (a) is incorrect because reduced genetic relatedness weakens cooperation.
Option (b) is incorrect because evolutionary transitions are not strictly irreversible.
Option (d) is incorrect because it includes statement D and omits conflict mediation, which is essential.