Life on earth will end .. just as it started

Scots scientists from the University of St. Andrew, Edinburgh and Dundee in Scotland, had a few days before the study results regarding how much more likely to last the life on Earth. Life course on earth essentially depends .. moods of the sun. The Sun, very slowly but steadily increases the intensity of the radiation. By this logic, these scientists estimate that approximately one billion years from now the Sun will become so strong that the Earth's average temperature will rise by nearly 100 degrees Celsius compared to current levels. As a result, all water on Earth will evaporate and the Earth will have the fate of the planet Venus. So almost all animal organisms will disappear and with them the human species, unless by then man has found ways and means to move to another planet.
But even that will disappear almost all life forms on Earth, but the microorganisms that live underground, that germs will be able to survive in this really hot atmosphere expected to occur on the planet. Microorganisms subsoil was the first form of life on Earth and is expected to be the last. But as the temperature increases on Earth, even the germs will not survive forever. Thus, it is estimated that about 3 billion years from now, the temperature of the earth will rise so much longer and even where the microbes will not be able to survive, turning a planet Earth without any life form.
For this reason, the Scots scientists arrived at the conclusion that the forms of life on other planets is essentially microorganisms that live underground and left no room for finding the existence of animal life form. Indeed, the more likely it is that planets that have life to have it in the form of microbes only, but this is not absolute. If there's an earth full of life because there are no planets like Earth with animal life and even intelligent beings? Certainly conditions for the existence of life beyond microbes are very difficult to occur after required conditions such as suitable composition of the planet, the ideal distance from its star, the proper motion of the planet, etc. But if the universe is literally endless because at certain points to no planets with appropriate conditions of life like Earth? statistically based should logically there are some other "worlds" like Earth that are full of life but the thing is that the nearest of these "worlds" can be located as far away from Earth where the modern technology make it impossible for the time being discovered this solar system and the planet ..