You are studying lizards in the field. The range of the northern population, species 1, overlaps the range of the southern population, species 2. You find hybrids in the zone of overlap. What is happening?
a. the postzygotic isolating mechanisms aren't working.
b. hybrids are best adapted to this region where overlap occurs.
c. reinforcement is occurring.
d. there is not enough information to decide what is happening.
Answer: d. there is not enough information to decide what is happening.
Explanation:
After speciation, the two resulting distinct species may proceed to cohabitate and interact. Their offspring are known as hybrids, and the hybrid zone is the space in which they interact and reproduce.
Whether they go through reinforcement (remain as two different species), or reconnection (going back to being one species), depends on the fitness of the offspring in comparison to the progenitors. Information on the environmental conditions, the population size, and whether or not any reproductive isolation mechanism has been applied are required for a proper evaluation of the situation.
