Post #13906

Proboscis blenny: How did elephant genes change the life of a tiny animal? What do the proboscis blenny and the elephant have in common? As is expected in such articles, the most obvious answer is the most incorrect answer. The proboscis of elephants and dogs were formed in completely different ways and have nothing in common. These animals are united by something more important and serious. Something that saves their lives. A long time ago, back in the Cretaceous period, Africa separated from the rest of the continents and for several tens of millions of years turned into a completely autonomous giant island. And on this island a bunch of primitive mammals were stuck, who had to somehow adapt to a variety of niches. This is how afrotheria appeared. Afrotheres are perhaps the most diverse group of mammals on the planet. In addition to giant elephants, it includes, for example, algae-eating sea cows, rodent-like hyraxes and even golden moles - a cuter version of moles. And, of course, our heroes are Peters’ dogs. Dogs are cute insectivorous animals weighing half a kilo, which are known to the world because of their strange intersexual relationships. Dogs are serially monogamous animals that can be faithful to one partner for their entire lives. But at the same time, they are extreme introverts who avoid contact even with their loved ones and prefer to stay away from each other. And they don’t even allow other proboscis dogs into their territory. And this is so different from elephants with their herds, powerful intra-family ties and a matriarch at the head! But at the cellular level they are much more similar. For example, almost all afrotheria have the same antitumor defense mechanism, and this mechanism copes with its task perfectly. It is so effective that it breaks the established rules of biology! Watch your hands, it won't be very easy now. One of the general trends in biology is the following: the larger the animal, the more effective its internal defense against the occurrence of tumors is. Therefore, in rats, tumors are the cause of 30% of non-violent deaths, while in humans, cancer is even less common, and sick elephants are very rare. Cancer in whales is only theoretically possible; in the entire history of observations, people have not found a single sick whale. The reason for this paradox is strict evolutionary selection. The larger the animal, the more cells it contains and, accordingly, the higher the chances that one of them will catch a mutation and degenerate into cancer. Therefore, the ability to fight tumors becomes a critical condition for natural selection. In addition, if a rat dies from cancer, there will be another 5-10 brothers and sisters from this litter alone, while a female whale may not give birth to 10 children in her entire life of almost a century. So it turns out that for large and not very fertile animals it is much more profitable to invest in protection and life expectancy. But, as we sa