Many pathogenic bacteria species are becoming resistant to antibiotics. explain how such adaptations can develop through the process of natural selectiontions .

Before human-made antibiotics, Antibiotic resistant bacteria existed. A good example is a penicillin, it is produced by antibiotic which is made by mold and the mold which makes the antibiotic to kill the bacteria and the one which would compete for material that mold gets its nutrition’s from.

That’s why we can say before humans developed, there were some penicillin-resistant bacteria. Most of the non-resistant bacteria die when exposed to an antibiotic. Some bacteria may have a resistance to the antibiotic because of mutations. Natural selection is all subject to bacteria. Most of them die if they don’t have the mutation which helps them to survive.

If those bacteria are exposed to a various antibiotic, then the same process occurs and that is how most strains of bacteria comes to multi-antibiotic resistant.

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.