A mutation could do that.
Stabilizing because the graph of this will be higher in the middle.
A good vector to genetically altered respiratory cells might be A VIRUS THAT HAS BEEN GENETICALLY ALTERED TO CARRY NORMAL HUMAN DNA.
Gene therapy is a medical method of treatment which uses genes to prevent or treat diseases. The method is used to correct the defects in genes which is causing a disease. In order to insert a normal gene to replace the defective one, a vector, which will carry the gene is needed. The vector that is usually used in this case is a virus, which has been doctored to carry a normal human DNA.
<span>After a long time, a mature community is established and this community does not change unless it is disturbed.</span>