Match the following
1. Temporal isolation a) Potential mates meet, but choose members of their own species.
2. Ecological isolation b) Individuals of different species do not mate because they are active at different times of the day or in different seasons.
3. Behavioral isolation c) Copulation is attempted, but a transfer of sperm does not take place.
4. Mechanical isolation d) Individuals mate in their preferred habitat, and therefore do not meet individuals of other species with different ecological preferences.

1a,2c,3b,4d

1c,2d,3b.,4a

1a,2b,3c,4d

1b.,2d.,3a.,4c.

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Concepts Covered - 1

Mechanism of Evolution: Reproductive Isolation

Isolation refers to the prevention of mating amongst interbreeding groups due to physical and biotic barriers.
Any factor which prevents interbreeding is called an isolating mechanism.
Pre-mating isolating mechanisms: Factors that cause species to mate with their own kind (assortative mating). It is of following types:
- Temporal isolation: Individuals of different species do not mate because they are active at different times of the day or in different seasons.
- Ecological isolation: Individuals mate in their preferred habitat, and therefore do not meet individuals of other species with different ecological preferences.
- Behavioral isolation: Potential mates meet, but choose members of their own species.
- Mechanical isolation: Copulation is attempted, but transfer of sperm does not take place.
Post-mating isolating mechanisms: Genomic incompatibility, hybrid inviability or sterility.
- Gametic incompatibility: Sperm transfer takes place, but the egg is not fertilized.
- Zygotic mortality: Egg is fertilized, but zygote does not develop.
- Hybrid inviability: Hybrid embryo forms, but of reduced viability.
- Hybrid sterility: Hybrid is viable, but the resulting adult is sterile.
- Hybrid breakdown: First generation (F1) hybrids are viable and fertile, but further hybrid generations (F2 and backcrosses) may be inviable or sterile.