Half horse, half whale
The ancestors of the whales lived on land 50 million years ago. Only then did they migrate into the sea and continuously adapt to their altered habitat. But researchers have found that whales still have many genes that mammals on land also have.
According to a study published in the science journal “Science Advances”, at least 85 genes have been suppressed over time to enable evolution from terrestrial to aquatic animals. Not only did the whale ancestors get bigger and bigger: “A gene involved in saliva production has presumably become superfluous, because a dry mouth in the sea is not a problem and the seawater significantly dilutes digestive enzymes in saliva anyway,” the scientists write. In addition, genes involved in blood coagulation changed: blood clots could become a problem, especially in animals that dive deep in the sea, while wound closure through blood coagulation under water is not very practical.