Icefishes live in the Southern Ocean, which encircles Antarctica. Icefishes have evolved to produce antifreeze proteins which prevent ice crystals from forming in their blood, when ocean temperatures...

Icefishes live in the Southern Ocean, which encircles Antarctica. Icefishes have evolved to produce antifreeze proteins which prevent ice crystals from forming in their blood, when ocean temperatures drop below the freezing point of fresh water.  The antifreeze proteins, which are produced in different amounts (high, medium and low) in different fishes, help them live in the cold waters.

1. What are the different variations of the antifreeze protein present in the population of icefish?

2. Out of the variations which one is the favorable trait in the environment of the icefish?

3. Which icefishes will natural selection select for?

4. How will the icefish population in very cold waters, change over time?

5. Describe the adaptation in icefish (in terms of allele frequency and reproductive fitness)