Savannah is the answer you are looking for here.
Answer:
blue whales migrating to mate and give birth
Explanation:
Scientists believed that it was HYDROGEN GAS that was used up before the oxygen gas become abundant in the atmosphere. Research shows that, millions of year ago, carbon dioxide was the most abundant gas in the atmosphere and that there is no oxygen at all. As time goes on and the earth mature, oxygen come into existence.
Dominant Genes!!!
Punnett Squares are fun