DID YOU KNOW?
According to research from the University of Pittsburgh School of Medicine, as marine mammals evolved to make water their primary habitat, they lost the ability to make a protein that defends humans and other land-dwelling mammals from the neurotoxic effects of a popular human-made pesticide. As oceans become increasingly polluted by pesticides, this lost protein may come back to haunt them. Through DNA analysis, researchers found that nearly all marine mammals have nonfunctional copies of a gene known as PON1, which encodes an enzyme called paraoxonase that can quickly break down chemicals found in a number of common fertilisers. Today, the increased presence of pesticides in marine ecosystems may have disastrous consequences for these water-dwelling mammals. SIZE MATTERS
Fascinatingly, aquatic mammals tend to be larger than their closest land-bound relatives.
The largest sea lions are twice as big as the largest bears, for example, and manatees outweigh their cat-sized hyrax cousins by nearly 500 kilograms. There is a reason why the blue whale is the largest animal on the planet!
According to the American Association for the Advancement of Science, scientists think this is because it’s too cold to survive in the ocean as a warm-blooded animal without a satisfactory size. The amount of heat your body can generate depends on how many cells you have, and small animals simply don’t have enough to replace the heat they lose to the water.
That means in the frigid sea, it’s better to be bigger.