Why did the giant lizards die out?

In the history of our planet there are phenomena whose causes have not yet been established. For example, why the giant lizards died out more than 60 million years ago. This question was tried in due time by Charles Darwin, who showed that the appearance of some species and the disappearance of others can be caused by changes in the external environment, as well as by the variability of the animals and plants themselves. As a result of these factors, most of the organisms survive, which acquire the characteristics best suited to external conditions. Any other deviations from the norm in the struggle for survival are doomed to extinction. However, in the period when giant lizards died out, one group of animals and plants replaced the other without a noticeable struggle for existence...

For example, why the giant lizards died out more than 60 million years ago

This happened on the verge of the last, Cretaceous period of the Mesozoic Era and the beginning of the modern Cenozoic Era. The hegemony of the giant lizards was undivided and unbreakable. The surface of the continents was shaken by the heavy trot of giant dinosaurs, the innumerable ichthyosaurs plowed the watery surface of the oceans, and winged pterodactyls flew through the air. And suddenly something unexpected happened. For an extremely short historical period, for some reason, all the giant lizards died out, giving way to mammals...

What force destroyed the giant pangolins? Many researchers have tried to connect these changes with various geological processes, as well as changes in the Earth's climate. Others expressed an interesting idea that everything is connected with the action of some cosmic cause. This assumption makes us pay special attention to the cosmic rays. Has the intensity of cosmic rays always remained unchanged during the existence of the Earth? To answer this question, it is necessary to know where cosmic rays come from, where and under what conditions they are born.

In cosmic rays, along with the nuclei of atoms, there are also electrons moving at high velocities. Such electrons, moving in interstellar magnetic fields, should radiate radio waves. These peculiar radio transmissions can be taken with the help of radio telescopes. In this way it is possible to obtain information about places of accumulation of cosmic particles.

For example, the Crab nebula, as well as similar nebulae formed as a result of supernova explosions, are powerful sources of radio emission. Thus, the Crab Nebula contains a huge amount of cosmic rays. With very distant flares, cosmic particles are gradually scattered in space due to the expansion of the gas nebula. Therefore, such flares practically can not exert any influence on the change in the intensity of cosmic radiation coming to Earth.

But if a supernova explosion occurs close enough, at a distance of no more than 25 light years, then after the expanding gas nebula reaches the solar system, the intensity of cosmic rays on Earth can increase substantially for a sufficiently long period.

Scientists have calculated that during the existence of our planet, about 10 outbreaks of close supernovae could occur. Therefore, it can be assumed that in the history of our planet there were periods when, for some time, the density of cosmic radiation was much higher than normal.

What were the consequences of this? As you know, all tissues and organs of living organisms are built from cells. One of the main parts of the cell is its core, inside which are chromosomes, which carry heredity, the molecular structure of which is a kind of coded record of all its many qualities. Thanks to the information contained in the chromosomes of germ cells, these qualities can be inherited.

However, under the influence of radioactive radiations, the so-called mutations, associated with the rearrangement of the molecular structure of chromosomes, can occur. As a result of such a restructuring, the descendants may have new qualities that parents did not have. Mutations can occur not only with artificial irradiation, but also under the influence of various natural factors. Such mutations are called spontaneous, or random. Mutations, as a rule, lead to the formation of defective forms, which under conditions of natural selection are doomed to inevitable extinction. This gives grounds to suppose why the giant lizards died out. Everything could be caused by a sufficiently prolonged increase in the intensity of cosmic radiation, which occurred as a result of the outburst of a nearby supernova.

In this connection, the residual radioactivity of fossil remains of a number of animals that lived on Earth for 400 million years was investigated. It was found that particularly high radioactivity occurs in the bones of various species of dinosaurs belonging to the era of their extinction.

In addition, it is known that on Earth there are such places where archaic forms of plants and animals have survived - in the depths of the seas and oceans, as well as in the depths of the Earth, ie, exactly where through the thickness of the water and layers of rocks cosmic rays do not penetrate.

The hypothesis about the effect of supernova explosions on the Earth and why the giant lizards have died out is only a hypothesis. Whether it is true or not, time will tell.