The surface tension of a liquid results from an imbalance of intermolecular attractive forces, the cohesive forces between molecules: A molecule in the bulk liquid experiences cohesive forces with other molecules in all directions. A molecule at the surface of a liquid experiences only net inward cohesive forces.
        
             
        
        
        
Answer:
Inbreeding  and greater chance of passing deletereous mutations through generations
Explanation:
There are several reasons why small populations are more prone to genetic diseases. One of them is that in small populations there tends to be more inbreeding
, that is breeding between individuals are closely related. Inbreeding increase the chances of offspring being affected by deletereus homozygous genotypes. 
On the other hand, the acquisition of a deleterious mutation in a small population is more likely to be spread in that small population  than in a large population.
 
        
                    
             
        
        
        
The water goes down to the roots