I believe the biosphere is fragile, because over time all of the pollution us humans have made; If its from air pulloution, acid rain or even water pollution. the toxic acids over time have made the biosphere and the ozon layer weaker and more thin. which causes the biosphere to become weaker.
        
                    
             
        
        
        
Hello,
Here is your answer:
The proper answer to this question is "the destruction of cells or tissues".
If you need anymore help feel free to ask me!
Hope this helps!
        
             
        
        
        
Creationists criticize the idea of natural selection as a circular argument, or tautology, claiming "the fittest are those that survive, and survival is how fitness is defined. " 
The definition of natural selection is not tautological because natural selection is measured by contribution to the next generation, not simply survival of an individual organism.
Tautologies or circular arguments are true at all times and therefore are not productive as theories since they cannot be disproved. A tautology is a statement which is true by necessity.
Natural selection is the prevalent theory which explains biological change by predicting the mechanism behind evolution. 
Nevertheless, natural selection can be explained non-tautologically. It should be described as the theory which tries to speculate as well as retrodict evolutionary change by environmental forces affecting the organisms.
To learn more about natural selection here
brainly.com/question/9830102
#SPJ4
 
        
             
        
        
        
If the comet were to strike the planet, the impact energy would be about 300 times that of the asteroid collision that was thought to have caused the Cretaceous-Tertiary extinction that killed the dinosaurs about 65 million years ago.
 
        
             
        
        
        
 Oxygen and carbon dioxide travels to and from tiny air sacs in the lungs, through the walls of the capillaries, into the blood. Blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs.
Oxygen and carbon dioxide travels to and from tiny air sacs in the lungs, through the walls of the capillaries, into the blood. Blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs.
