Are there favorable mutations?
There are, but it can be hard to tell. For a number of reasons it is not simple to give examples of favorable mutations. First of all, as we have seen, traits [6] may be favorable or unfavorable, depending upon the environment. Secondly it is not usually known to what extent a trait is genetically fixed and to what extent it reflects a reaction to the environment. Thirdly we don’t usually know what genes effect which traits. Moreover a mutation may be favorable in the sense that it permits survival in an unfavorable environment and yet be unfavorable in a better environment. However there are a number of good examples: • Antibiotic resistance in bacteria In modern times antibiotics, drugs that target specific features of bacteria, have become very popular. Bacteria evolve very quickly so it is not surprising that they have evolved resistance to antibiotics. As a general thing this involves changing the features that antibiotics target. Commonly, but not always, these mutations decrease
