It was beneficial for northern Europeans to be lactose tolerant when lactose intolerance was more common in most other places because of the fact of the lactase mutation and natural refrigeration of the climate
<u>Explanation:</u>
The most of the places in the world was lactose intolerant as when a child is born, the baby is lactose tolerant and so uptakes as many lactose as needs for it but then while growing up, the enzyme to digest those lactose are lactase which are found to be decreasing in the adult and so adult becomes lactose intolerants.
But in the North Europe and some parts of Central Europe, the climate served to be the natural refrigerator and by the advent of mutation. Northern Europeans became lactose tolerant, as they tend to retain the lactase enzyme. This was assisted with the famine conditions which let the adult have milk as the only option of food and energy.
Turtles are excellent divers, but from time to time they must go back to the surface to breathe. As turtles have a carapace, they can not extend and contract the ribs to breathe. Instead, they use their fin muscles and swimming movement to bomb air from inside to outside of the lungs. Many turtles species can not dive in deeps because their carapace is so hard that it might crush as they are diving because of water pressure. But some other species are adapted to deep-diving. These marine turtles keep huge amounts of oxygen in their muscles and blood instead of keeping them in the lungs. They can dive for a very long time in the deep, most of the time foraging, escaping from predators or to regulate their body temperature. These species can handle the pressure because their carapace is not that hard, so it allows the body to compress and not to be crushed by water pressure.
Most aquatic snakes are known to dive near the surface, where water is warmer and helps them to regulate their body temperature. But some other species are adapted to dive up to 250 meters deep where they can forage over a wider amount of prey. Independently of how deep they can swim, all of these aquatic animals must go back to the surface for gas exchanging. They can hold the breath for 5 or 6 hours, but after that period they must breathe. Some marine snakes are adapted to deep diving: their bodies are very laterally comprised and they can face the breathing problem through skin gas exchanging. Although they have developed these adaptations, at some point they must breathe.
Water Lilies need light and warm water to grow. They grow fast and colonize illuminated places, in warm and shallow water. The deeper the plant is located, the slower it will grow. These plants can not live in waters over five feet deep, because deep water is cold and poorly lighted, and tubers and rhizomes take a long time to establish in these places.
Mangrove trees have roots called pneumatophores that allow them to take oxygen from the air and produce gas exchange. They can resist a periodic submersion but they need to drain. If these roots are constantly underwater they can not accomplish their respiratory function and the tree eventually dies. These species have different strategies to deal with salt, one of excreting it by their leaves. If leaves are underwater, they are not able to do this, increasing salt levels in their system.
<span>An organism may not be able to survive on just fermentation because the fermentation process does not produce very much energy. If an organism were to be able to survive on fermentation alone, the organism would have to be extremely small.</span>